Check retval value and convert to error in generated RPC client code

Change-Id: I816b4802cb5fc46239f6db0480fa4cf3645fe2f0
Signed-off-by: Ondrej Fabry <ofabry@cisco.com>

292 files changed, 809 insertions, 13273 deletions

diff --git a/binapi/abf/abf.ba.go b/binapi/abf/abf.ba.go
index 2b28afe..fc4351b 100644
--- a/binapi/abf/abf.ba.go
+++ b/binapi/abf/abf.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/abf.api.json
 
 // Package abf contains generated bindings for API file abf.api.
diff --git a/binapi/abf/abf_rest.ba.go b/binapi/abf/abf_rest.ba.go
deleted file mode 100644
index e05e834..0000000
--- a/binapi/abf/abf_rest.ba.go
+++ /dev/null
@@ -1,74 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package abf
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/abf_itf_attach_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AbfItfAttachAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AbfItfAttachAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/abf_plugin_get_version", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AbfPluginGetVersion)
-		reply, err := rpc.AbfPluginGetVersion(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/abf_policy_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AbfPolicyAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AbfPolicyAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/abf/abf_rpc.ba.go b/binapi/abf/abf_rpc.ba.go
index 9498ff6..5b2f825 100644
--- a/binapi/abf/abf_rpc.ba.go
+++ b/binapi/abf/abf_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  abf.
+// RPCService defines RPC service abf.
 type RPCService interface {
 	AbfItfAttachAddDel(ctx context.Context, in *AbfItfAttachAddDel) (*AbfItfAttachAddDelReply, error)
 	AbfItfAttachDump(ctx context.Context, in *AbfItfAttachDump) (RPCService_AbfItfAttachDumpClient, error)
@@ -34,7 +34,7 @@ func (c *serviceClient) AbfItfAttachAddDel(ctx context.Context, in *AbfItfAttach
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) AbfItfAttachDump(ctx context.Context, in *AbfItfAttachDump) (RPCService_AbfItfAttachDumpClient, error) {
@@ -91,7 +91,7 @@ func (c *serviceClient) AbfPolicyAddDel(ctx context.Context, in *AbfPolicyAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) AbfPolicyDump(ctx context.Context, in *AbfPolicyDump) (RPCService_AbfPolicyDumpClient, error) {
diff --git a/binapi/acl/acl.ba.go b/binapi/acl/acl.ba.go
index 1f47a01..c1114f1 100644
--- a/binapi/acl/acl.ba.go
+++ b/binapi/acl/acl.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/acl.api.json
 
 // Package acl contains generated bindings for API file acl.api.
diff --git a/binapi/acl/acl_rest.ba.go b/binapi/acl/acl_rest.ba.go
deleted file mode 100644
index 0dd8c94..0000000
--- a/binapi/acl/acl_rest.ba.go
+++ /dev/null
@@ -1,300 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package acl
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/acl_add_replace", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ACLAddReplace)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ACLAddReplace(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/acl_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ACLDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ACLDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/acl_interface_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ACLInterfaceAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ACLInterfaceAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/acl_interface_set_acl_list", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ACLInterfaceSetACLList)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ACLInterfaceSetACLList(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/acl_interface_set_etype_whitelist", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ACLInterfaceSetEtypeWhitelist)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ACLInterfaceSetEtypeWhitelist(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/acl_plugin_control_ping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ACLPluginControlPing)
-		reply, err := rpc.ACLPluginControlPing(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/acl_plugin_get_conn_table_max_entries", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ACLPluginGetConnTableMaxEntries)
-		reply, err := rpc.ACLPluginGetConnTableMaxEntries(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/acl_plugin_get_version", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ACLPluginGetVersion)
-		reply, err := rpc.ACLPluginGetVersion(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/acl_stats_intf_counters_enable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ACLStatsIntfCountersEnable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ACLStatsIntfCountersEnable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/macip_acl_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MacipACLAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MacipACLAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/macip_acl_add_replace", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MacipACLAddReplace)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MacipACLAddReplace(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/macip_acl_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MacipACLDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MacipACLDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/macip_acl_interface_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MacipACLInterfaceAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MacipACLInterfaceAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/macip_acl_interface_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MacipACLInterfaceGet)
-		reply, err := rpc.MacipACLInterfaceGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/acl/acl_rpc.ba.go b/binapi/acl/acl_rpc.ba.go
index d1d2220..da1ecca 100644
--- a/binapi/acl/acl_rpc.ba.go
+++ b/binapi/acl/acl_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  acl.
+// RPCService defines RPC service acl.
 type RPCService interface {
 	ACLAddReplace(ctx context.Context, in *ACLAddReplace) (*ACLAddReplaceReply, error)
 	ACLDel(ctx context.Context, in *ACLDel) (*ACLDelReply, error)
@@ -48,7 +48,7 @@ func (c *serviceClient) ACLAddReplace(ctx context.Context, in *ACLAddReplace) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ACLDel(ctx context.Context, in *ACLDel) (*ACLDelReply, error) {
@@ -57,7 +57,7 @@ func (c *serviceClient) ACLDel(ctx context.Context, in *ACLDel) (*ACLDelReply, e
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ACLDump(ctx context.Context, in *ACLDump) (RPCService_ACLDumpClient, error) {
@@ -105,7 +105,7 @@ func (c *serviceClient) ACLInterfaceAddDel(ctx context.Context, in *ACLInterface
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ACLInterfaceEtypeWhitelistDump(ctx context.Context, in *ACLInterfaceEtypeWhitelistDump) (RPCService_ACLInterfaceEtypeWhitelistDumpClient, error) {
@@ -192,7 +192,7 @@ func (c *serviceClient) ACLInterfaceSetACLList(ctx context.Context, in *ACLInter
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ACLInterfaceSetEtypeWhitelist(ctx context.Context, in *ACLInterfaceSetEtypeWhitelist) (*ACLInterfaceSetEtypeWhitelistReply, error) {
@@ -201,7 +201,7 @@ func (c *serviceClient) ACLInterfaceSetEtypeWhitelist(ctx context.Context, in *A
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ACLPluginControlPing(ctx context.Context, in *ACLPluginControlPing) (*ACLPluginControlPingReply, error) {
@@ -210,7 +210,7 @@ func (c *serviceClient) ACLPluginControlPing(ctx context.Context, in *ACLPluginC
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ACLPluginGetConnTableMaxEntries(ctx context.Context, in *ACLPluginGetConnTableMaxEntries) (*ACLPluginGetConnTableMaxEntriesReply, error) {
@@ -237,7 +237,7 @@ func (c *serviceClient) ACLStatsIntfCountersEnable(ctx context.Context, in *ACLS
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MacipACLAdd(ctx context.Context, in *MacipACLAdd) (*MacipACLAddReply, error) {
@@ -246,7 +246,7 @@ func (c *serviceClient) MacipACLAdd(ctx context.Context, in *MacipACLAdd) (*Maci
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MacipACLAddReplace(ctx context.Context, in *MacipACLAddReplace) (*MacipACLAddReplaceReply, error) {
@@ -255,7 +255,7 @@ func (c *serviceClient) MacipACLAddReplace(ctx context.Context, in *MacipACLAddR
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MacipACLDel(ctx context.Context, in *MacipACLDel) (*MacipACLDelReply, error) {
@@ -264,7 +264,7 @@ func (c *serviceClient) MacipACLDel(ctx context.Context, in *MacipACLDel) (*Maci
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MacipACLDump(ctx context.Context, in *MacipACLDump) (RPCService_MacipACLDumpClient, error) {
@@ -312,7 +312,7 @@ func (c *serviceClient) MacipACLInterfaceAddDel(ctx context.Context, in *MacipAC
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MacipACLInterfaceGet(ctx context.Context, in *MacipACLInterfaceGet) (*MacipACLInterfaceGetReply, error) {
diff --git a/binapi/acl_types/acl_types.ba.go b/binapi/acl_types/acl_types.ba.go
index 0c8efc2..27f951f 100644
--- a/binapi/acl_types/acl_types.ba.go
+++ b/binapi/acl_types/acl_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/acl_types.api.json
 
 // Package acl_types contains generated bindings for API file acl_types.api.
diff --git a/binapi/af_packet/af_packet.ba.go b/binapi/af_packet/af_packet.ba.go
index 750e2ce..9cde877 100644
--- a/binapi/af_packet/af_packet.ba.go
+++ b/binapi/af_packet/af_packet.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/af_packet.api.json
 
 // Package af_packet contains generated bindings for API file af_packet.api.
diff --git a/binapi/af_packet/af_packet_rest.ba.go b/binapi/af_packet/af_packet_rest.ba.go
deleted file mode 100644
index e6c498c..0000000
--- a/binapi/af_packet/af_packet_rest.ba.go
+++ /dev/null
@@ -1,83 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package af_packet
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/af_packet_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AfPacketCreate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AfPacketCreate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/af_packet_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AfPacketDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AfPacketDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/af_packet_set_l4_cksum_offload", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AfPacketSetL4CksumOffload)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AfPacketSetL4CksumOffload(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/af_packet/af_packet_rpc.ba.go b/binapi/af_packet/af_packet_rpc.ba.go
index 0603e3b..f8c3732 100644
--- a/binapi/af_packet/af_packet_rpc.ba.go
+++ b/binapi/af_packet/af_packet_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  af_packet.
+// RPCService defines RPC service af_packet.
 type RPCService interface {
 	AfPacketCreate(ctx context.Context, in *AfPacketCreate) (*AfPacketCreateReply, error)
 	AfPacketDelete(ctx context.Context, in *AfPacketDelete) (*AfPacketDeleteReply, error)
@@ -33,7 +33,7 @@ func (c *serviceClient) AfPacketCreate(ctx context.Context, in *AfPacketCreate)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) AfPacketDelete(ctx context.Context, in *AfPacketDelete) (*AfPacketDeleteReply, error) {
@@ -42,7 +42,7 @@ func (c *serviceClient) AfPacketDelete(ctx context.Context, in *AfPacketDelete)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) AfPacketDump(ctx context.Context, in *AfPacketDump) (RPCService_AfPacketDumpClient, error) {
@@ -90,5 +90,5 @@ func (c *serviceClient) AfPacketSetL4CksumOffload(ctx context.Context, in *AfPac
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/arp/arp.ba.go b/binapi/arp/arp.ba.go
index 90ff55b..e36c837 100644
--- a/binapi/arp/arp.ba.go
+++ b/binapi/arp/arp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/arp.api.json
 
 // Package arp contains generated bindings for API file arp.api.
diff --git a/binapi/arp/arp_rest.ba.go b/binapi/arp/arp_rest.ba.go
deleted file mode 100644
index 71a07d9..0000000
--- a/binapi/arp/arp_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package arp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/proxy_arp_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ProxyArpAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ProxyArpAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/proxy_arp_intfc_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ProxyArpIntfcEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ProxyArpIntfcEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/arp/arp_rpc.ba.go b/binapi/arp/arp_rpc.ba.go
index 8bb64ce..6e60bf3 100644
--- a/binapi/arp/arp_rpc.ba.go
+++ b/binapi/arp/arp_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  arp.
+// RPCService defines RPC service arp.
 type RPCService interface {
 	ProxyArpAddDel(ctx context.Context, in *ProxyArpAddDel) (*ProxyArpAddDelReply, error)
 	ProxyArpDump(ctx context.Context, in *ProxyArpDump) (RPCService_ProxyArpDumpClient, error)
@@ -33,7 +33,7 @@ func (c *serviceClient) ProxyArpAddDel(ctx context.Context, in *ProxyArpAddDel)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ProxyArpDump(ctx context.Context, in *ProxyArpDump) (RPCService_ProxyArpDumpClient, error) {
@@ -120,5 +120,5 @@ func (c *serviceClient) ProxyArpIntfcEnableDisable(ctx context.Context, in *Prox
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/avf/avf.ba.go b/binapi/avf/avf.ba.go
index edfa26e..0dc1ac0 100644
--- a/binapi/avf/avf.ba.go
+++ b/binapi/avf/avf.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/avf.api.json
 
 // Package avf contains generated bindings for API file avf.api.
diff --git a/binapi/avf/avf_rest.ba.go b/binapi/avf/avf_rest.ba.go
deleted file mode 100644
index 1a9d7f3..0000000
--- a/binapi/avf/avf_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package avf
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/avf_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AvfCreate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AvfCreate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/avf_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AvfDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AvfDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/avf/avf_rpc.ba.go b/binapi/avf/avf_rpc.ba.go
index 46aa77c..5747834 100644
--- a/binapi/avf/avf_rpc.ba.go
+++ b/binapi/avf/avf_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  avf.
+// RPCService defines RPC service avf.
 type RPCService interface {
 	AvfCreate(ctx context.Context, in *AvfCreate) (*AvfCreateReply, error)
 	AvfDelete(ctx context.Context, in *AvfDelete) (*AvfDeleteReply, error)
@@ -28,7 +28,7 @@ func (c *serviceClient) AvfCreate(ctx context.Context, in *AvfCreate) (*AvfCreat
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) AvfDelete(ctx context.Context, in *AvfDelete) (*AvfDeleteReply, error) {
@@ -37,5 +37,5 @@ func (c *serviceClient) AvfDelete(ctx context.Context, in *AvfDelete) (*AvfDelet
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/bfd/bfd.ba.go b/binapi/bfd/bfd.ba.go
index 65b828f..624bc22 100644
--- a/binapi/bfd/bfd.ba.go
+++ b/binapi/bfd/bfd.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/bfd.api.json
 
 // Package bfd contains generated bindings for API file bfd.api.
diff --git a/binapi/bfd/bfd_rest.ba.go b/binapi/bfd/bfd_rest.ba.go
deleted file mode 100644
index 2f25f8b..0000000
--- a/binapi/bfd/bfd_rest.ba.go
+++ /dev/null
@@ -1,272 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package bfd
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/bfd_auth_del_key", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdAuthDelKey)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BfdAuthDelKey(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bfd_auth_set_key", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdAuthSetKey)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BfdAuthSetKey(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bfd_udp_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdUDPAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BfdUDPAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bfd_udp_auth_activate", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdUDPAuthActivate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BfdUDPAuthActivate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bfd_udp_auth_deactivate", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdUDPAuthDeactivate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BfdUDPAuthDeactivate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bfd_udp_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdUDPDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BfdUDPDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bfd_udp_del_echo_source", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdUDPDelEchoSource)
-		reply, err := rpc.BfdUDPDelEchoSource(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bfd_udp_get_echo_source", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdUDPGetEchoSource)
-		reply, err := rpc.BfdUDPGetEchoSource(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bfd_udp_mod", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdUDPMod)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BfdUDPMod(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bfd_udp_session_set_flags", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdUDPSessionSetFlags)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BfdUDPSessionSetFlags(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bfd_udp_set_echo_source", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BfdUDPSetEchoSource)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BfdUDPSetEchoSource(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/want_bfd_events", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(WantBfdEvents)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.WantBfdEvents(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/bfd/bfd_rpc.ba.go b/binapi/bfd/bfd_rpc.ba.go
index 68a9893..a2e5c5c 100644
--- a/binapi/bfd/bfd_rpc.ba.go
+++ b/binapi/bfd/bfd_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  bfd.
+// RPCService defines RPC service bfd.
 type RPCService interface {
 	BfdAuthDelKey(ctx context.Context, in *BfdAuthDelKey) (*BfdAuthDelKeyReply, error)
 	BfdAuthKeysDump(ctx context.Context, in *BfdAuthKeysDump) (RPCService_BfdAuthKeysDumpClient, error)
@@ -43,7 +43,7 @@ func (c *serviceClient) BfdAuthDelKey(ctx context.Context, in *BfdAuthDelKey) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BfdAuthKeysDump(ctx context.Context, in *BfdAuthKeysDump) (RPCService_BfdAuthKeysDumpClient, error) {
@@ -91,7 +91,7 @@ func (c *serviceClient) BfdAuthSetKey(ctx context.Context, in *BfdAuthSetKey) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BfdUDPAdd(ctx context.Context, in *BfdUDPAdd) (*BfdUDPAddReply, error) {
@@ -100,7 +100,7 @@ func (c *serviceClient) BfdUDPAdd(ctx context.Context, in *BfdUDPAdd) (*BfdUDPAd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BfdUDPAuthActivate(ctx context.Context, in *BfdUDPAuthActivate) (*BfdUDPAuthActivateReply, error) {
@@ -109,7 +109,7 @@ func (c *serviceClient) BfdUDPAuthActivate(ctx context.Context, in *BfdUDPAuthAc
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BfdUDPAuthDeactivate(ctx context.Context, in *BfdUDPAuthDeactivate) (*BfdUDPAuthDeactivateReply, error) {
@@ -118,7 +118,7 @@ func (c *serviceClient) BfdUDPAuthDeactivate(ctx context.Context, in *BfdUDPAuth
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BfdUDPDel(ctx context.Context, in *BfdUDPDel) (*BfdUDPDelReply, error) {
@@ -127,7 +127,7 @@ func (c *serviceClient) BfdUDPDel(ctx context.Context, in *BfdUDPDel) (*BfdUDPDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BfdUDPDelEchoSource(ctx context.Context, in *BfdUDPDelEchoSource) (*BfdUDPDelEchoSourceReply, error) {
@@ -136,7 +136,7 @@ func (c *serviceClient) BfdUDPDelEchoSource(ctx context.Context, in *BfdUDPDelEc
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BfdUDPGetEchoSource(ctx context.Context, in *BfdUDPGetEchoSource) (*BfdUDPGetEchoSourceReply, error) {
@@ -145,7 +145,7 @@ func (c *serviceClient) BfdUDPGetEchoSource(ctx context.Context, in *BfdUDPGetEc
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BfdUDPMod(ctx context.Context, in *BfdUDPMod) (*BfdUDPModReply, error) {
@@ -154,7 +154,7 @@ func (c *serviceClient) BfdUDPMod(ctx context.Context, in *BfdUDPMod) (*BfdUDPMo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BfdUDPSessionDump(ctx context.Context, in *BfdUDPSessionDump) (RPCService_BfdUDPSessionDumpClient, error) {
@@ -202,7 +202,7 @@ func (c *serviceClient) BfdUDPSessionSetFlags(ctx context.Context, in *BfdUDPSes
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BfdUDPSetEchoSource(ctx context.Context, in *BfdUDPSetEchoSource) (*BfdUDPSetEchoSourceReply, error) {
@@ -211,7 +211,7 @@ func (c *serviceClient) BfdUDPSetEchoSource(ctx context.Context, in *BfdUDPSetEc
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) WantBfdEvents(ctx context.Context, in *WantBfdEvents) (*WantBfdEventsReply, error) {
@@ -220,5 +220,5 @@ func (c *serviceClient) WantBfdEvents(ctx context.Context, in *WantBfdEvents) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/bier/bier.ba.go b/binapi/bier/bier.ba.go
index f024d80..76b1c77 100644
--- a/binapi/bier/bier.ba.go
+++ b/binapi/bier/bier.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/bier.api.json
 
 // Package bier contains generated bindings for API file bier.api.
diff --git a/binapi/bier/bier_rest.ba.go b/binapi/bier/bier_rest.ba.go
deleted file mode 100644
index f65f8f3..0000000
--- a/binapi/bier/bier_rest.ba.go
+++ /dev/null
@@ -1,152 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package bier
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/bier_disp_entry_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BierDispEntryAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BierDispEntryAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bier_disp_table_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BierDispTableAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BierDispTableAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bier_imp_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BierImpAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BierImpAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bier_imp_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BierImpDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BierImpDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bier_route_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BierRouteAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BierRouteAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bier_table_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BierTableAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BierTableAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/bier/bier_rpc.ba.go b/binapi/bier/bier_rpc.ba.go
index f2e44c6..56b027c 100644
--- a/binapi/bier/bier_rpc.ba.go
+++ b/binapi/bier/bier_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  bier.
+// RPCService defines RPC service bier.
 type RPCService interface {
 	BierDispEntryAddDel(ctx context.Context, in *BierDispEntryAddDel) (*BierDispEntryAddDelReply, error)
 	BierDispEntryDump(ctx context.Context, in *BierDispEntryDump) (RPCService_BierDispEntryDumpClient, error)
@@ -40,7 +40,7 @@ func (c *serviceClient) BierDispEntryAddDel(ctx context.Context, in *BierDispEnt
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BierDispEntryDump(ctx context.Context, in *BierDispEntryDump) (RPCService_BierDispEntryDumpClient, error) {
@@ -88,7 +88,7 @@ func (c *serviceClient) BierDispTableAddDel(ctx context.Context, in *BierDispTab
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BierDispTableDump(ctx context.Context, in *BierDispTableDump) (RPCService_BierDispTableDumpClient, error) {
@@ -136,7 +136,7 @@ func (c *serviceClient) BierImpAdd(ctx context.Context, in *BierImpAdd) (*BierIm
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BierImpDel(ctx context.Context, in *BierImpDel) (*BierImpDelReply, error) {
@@ -145,7 +145,7 @@ func (c *serviceClient) BierImpDel(ctx context.Context, in *BierImpDel) (*BierIm
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BierImpDump(ctx context.Context, in *BierImpDump) (RPCService_BierImpDumpClient, error) {
@@ -193,7 +193,7 @@ func (c *serviceClient) BierRouteAddDel(ctx context.Context, in *BierRouteAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BierRouteDump(ctx context.Context, in *BierRouteDump) (RPCService_BierRouteDumpClient, error) {
@@ -241,7 +241,7 @@ func (c *serviceClient) BierTableAddDel(ctx context.Context, in *BierTableAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BierTableDump(ctx context.Context, in *BierTableDump) (RPCService_BierTableDumpClient, error) {
diff --git a/binapi/bond/bond.ba.go b/binapi/bond/bond.ba.go
index c9e7027..61aafc7 100644
--- a/binapi/bond/bond.ba.go
+++ b/binapi/bond/bond.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/bond.api.json
 
 // Package bond contains generated bindings for API file bond.api.
diff --git a/binapi/bond/bond_rest.ba.go b/binapi/bond/bond_rest.ba.go
deleted file mode 100644
index c1893d5..0000000
--- a/binapi/bond/bond_rest.ba.go
+++ /dev/null
@@ -1,129 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package bond
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/bond_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BondCreate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BondCreate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bond_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BondDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BondDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bond_detach_slave", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BondDetachSlave)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BondDetachSlave(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bond_enslave", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BondEnslave)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BondEnslave(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_bond_weight", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetBondWeight)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetBondWeight(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/bond/bond_rpc.ba.go b/binapi/bond/bond_rpc.ba.go
index 8e3b254..67fc538 100644
--- a/binapi/bond/bond_rpc.ba.go
+++ b/binapi/bond/bond_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  bond.
+// RPCService defines RPC service bond.
 type RPCService interface {
 	BondCreate(ctx context.Context, in *BondCreate) (*BondCreateReply, error)
 	BondDelete(ctx context.Context, in *BondDelete) (*BondDeleteReply, error)
@@ -36,7 +36,7 @@ func (c *serviceClient) BondCreate(ctx context.Context, in *BondCreate) (*BondCr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BondDelete(ctx context.Context, in *BondDelete) (*BondDeleteReply, error) {
@@ -45,7 +45,7 @@ func (c *serviceClient) BondDelete(ctx context.Context, in *BondDelete) (*BondDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BondDetachSlave(ctx context.Context, in *BondDetachSlave) (*BondDetachSlaveReply, error) {
@@ -54,7 +54,7 @@ func (c *serviceClient) BondDetachSlave(ctx context.Context, in *BondDetachSlave
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BondEnslave(ctx context.Context, in *BondEnslave) (*BondEnslaveReply, error) {
@@ -63,7 +63,7 @@ func (c *serviceClient) BondEnslave(ctx context.Context, in *BondEnslave) (*Bond
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceBondDump(ctx context.Context, in *SwInterfaceBondDump) (RPCService_SwInterfaceBondDumpClient, error) {
@@ -111,7 +111,7 @@ func (c *serviceClient) SwInterfaceSetBondWeight(ctx context.Context, in *SwInte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSlaveDump(ctx context.Context, in *SwInterfaceSlaveDump) (RPCService_SwInterfaceSlaveDumpClient, error) {
diff --git a/binapi/builtinurl/builtinurl.ba.go b/binapi/builtinurl/builtinurl.ba.go
index 6b0350d..2c3ccf2 100644
--- a/binapi/builtinurl/builtinurl.ba.go
+++ b/binapi/builtinurl/builtinurl.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/builtinurl.api.json
 
 // Package builtinurl contains generated bindings for API file builtinurl.api.
diff --git a/binapi/builtinurl/builtinurl_rest.ba.go b/binapi/builtinurl/builtinurl_rest.ba.go
deleted file mode 100644
index a4373f1..0000000
--- a/binapi/builtinurl/builtinurl_rest.ba.go
+++ /dev/null
@@ -1,27 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package builtinurl
-
-import (
-	"encoding/json"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/builtinurl_enable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BuiltinurlEnable)
-		reply, err := rpc.BuiltinurlEnable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/builtinurl/builtinurl_rpc.ba.go b/binapi/builtinurl/builtinurl_rpc.ba.go
index 2edf7d5..f44e843 100644
--- a/binapi/builtinurl/builtinurl_rpc.ba.go
+++ b/binapi/builtinurl/builtinurl_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  builtinurl.
+// RPCService defines RPC service builtinurl.
 type RPCService interface {
 	BuiltinurlEnable(ctx context.Context, in *BuiltinurlEnable) (*BuiltinurlEnableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) BuiltinurlEnable(ctx context.Context, in *BuiltinurlEnab
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/cdp/cdp.ba.go b/binapi/cdp/cdp.ba.go
index 5430d74..dbee58e 100644
--- a/binapi/cdp/cdp.ba.go
+++ b/binapi/cdp/cdp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/cdp.api.json
 
 // Package cdp contains generated bindings for API file cdp.api.
diff --git a/binapi/cdp/cdp_rest.ba.go b/binapi/cdp/cdp_rest.ba.go
deleted file mode 100644
index b414757..0000000
--- a/binapi/cdp/cdp_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package cdp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/cdp_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(CdpEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.CdpEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/cdp/cdp_rpc.ba.go b/binapi/cdp/cdp_rpc.ba.go
index 1933d2f..8eac86c 100644
--- a/binapi/cdp/cdp_rpc.ba.go
+++ b/binapi/cdp/cdp_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  cdp.
+// RPCService defines RPC service cdp.
 type RPCService interface {
 	CdpEnableDisable(ctx context.Context, in *CdpEnableDisable) (*CdpEnableDisableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) CdpEnableDisable(ctx context.Context, in *CdpEnableDisab
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/classify/classify.ba.go b/binapi/classify/classify.ba.go
index 16bc4b8..89be260 100644
--- a/binapi/classify/classify.ba.go
+++ b/binapi/classify/classify.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/classify.api.json
 
 // Package classify contains generated bindings for API file classify.api.
diff --git a/binapi/classify/classify_rest.ba.go b/binapi/classify/classify_rest.ba.go
deleted file mode 100644
index f50fefd..0000000
--- a/binapi/classify/classify_rest.ba.go
+++ /dev/null
@@ -1,258 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package classify
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/classify_add_del_session", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ClassifyAddDelSession)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ClassifyAddDelSession(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/classify_add_del_table", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ClassifyAddDelTable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ClassifyAddDelTable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/classify_set_interface_ip_table", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ClassifySetInterfaceIPTable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ClassifySetInterfaceIPTable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/classify_set_interface_l2_tables", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ClassifySetInterfaceL2Tables)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ClassifySetInterfaceL2Tables(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/classify_table_by_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ClassifyTableByInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ClassifyTableByInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/classify_table_ids", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ClassifyTableIds)
-		reply, err := rpc.ClassifyTableIds(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/classify_table_info", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ClassifyTableInfo)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ClassifyTableInfo(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/flow_classify_set_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(FlowClassifySetInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.FlowClassifySetInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/input_acl_set_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(InputACLSetInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.InputACLSetInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/output_acl_set_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OutputACLSetInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OutputACLSetInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/policer_classify_set_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PolicerClassifySetInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PolicerClassifySetInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/classify/classify_rpc.ba.go b/binapi/classify/classify_rpc.ba.go
index de29fa5..5bbb43b 100644
--- a/binapi/classify/classify_rpc.ba.go
+++ b/binapi/classify/classify_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  classify.
+// RPCService defines RPC service classify.
 type RPCService interface {
 	ClassifyAddDelSession(ctx context.Context, in *ClassifyAddDelSession) (*ClassifyAddDelSessionReply, error)
 	ClassifyAddDelTable(ctx context.Context, in *ClassifyAddDelTable) (*ClassifyAddDelTableReply, error)
@@ -43,7 +43,7 @@ func (c *serviceClient) ClassifyAddDelSession(ctx context.Context, in *ClassifyA
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ClassifyAddDelTable(ctx context.Context, in *ClassifyAddDelTable) (*ClassifyAddDelTableReply, error) {
@@ -52,7 +52,7 @@ func (c *serviceClient) ClassifyAddDelTable(ctx context.Context, in *ClassifyAdd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ClassifySessionDump(ctx context.Context, in *ClassifySessionDump) (RPCService_ClassifySessionDumpClient, error) {
@@ -100,7 +100,7 @@ func (c *serviceClient) ClassifySetInterfaceIPTable(ctx context.Context, in *Cla
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ClassifySetInterfaceL2Tables(ctx context.Context, in *ClassifySetInterfaceL2Tables) (*ClassifySetInterfaceL2TablesReply, error) {
@@ -109,7 +109,7 @@ func (c *serviceClient) ClassifySetInterfaceL2Tables(ctx context.Context, in *Cl
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ClassifyTableByInterface(ctx context.Context, in *ClassifyTableByInterface) (*ClassifyTableByInterfaceReply, error) {
@@ -118,7 +118,7 @@ func (c *serviceClient) ClassifyTableByInterface(ctx context.Context, in *Classi
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ClassifyTableIds(ctx context.Context, in *ClassifyTableIds) (*ClassifyTableIdsReply, error) {
@@ -127,7 +127,7 @@ func (c *serviceClient) ClassifyTableIds(ctx context.Context, in *ClassifyTableI
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ClassifyTableInfo(ctx context.Context, in *ClassifyTableInfo) (*ClassifyTableInfoReply, error) {
@@ -136,7 +136,7 @@ func (c *serviceClient) ClassifyTableInfo(ctx context.Context, in *ClassifyTable
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) FlowClassifyDump(ctx context.Context, in *FlowClassifyDump) (RPCService_FlowClassifyDumpClient, error) {
@@ -184,7 +184,7 @@ func (c *serviceClient) FlowClassifySetInterface(ctx context.Context, in *FlowCl
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) InputACLSetInterface(ctx context.Context, in *InputACLSetInterface) (*InputACLSetInterfaceReply, error) {
@@ -193,7 +193,7 @@ func (c *serviceClient) InputACLSetInterface(ctx context.Context, in *InputACLSe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OutputACLSetInterface(ctx context.Context, in *OutputACLSetInterface) (*OutputACLSetInterfaceReply, error) {
@@ -202,7 +202,7 @@ func (c *serviceClient) OutputACLSetInterface(ctx context.Context, in *OutputACL
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PolicerClassifyDump(ctx context.Context, in *PolicerClassifyDump) (RPCService_PolicerClassifyDumpClient, error) {
@@ -250,5 +250,5 @@ func (c *serviceClient) PolicerClassifySetInterface(ctx context.Context, in *Pol
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/cop/cop.ba.go b/binapi/cop/cop.ba.go
index 14f0b11..6159982 100644
--- a/binapi/cop/cop.ba.go
+++ b/binapi/cop/cop.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/cop.api.json
 
 // Package cop contains generated bindings for API file cop.api.
diff --git a/binapi/cop/cop_rest.ba.go b/binapi/cop/cop_rest.ba.go
deleted file mode 100644
index d9ed487..0000000
--- a/binapi/cop/cop_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package cop
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/cop_interface_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(CopInterfaceEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.CopInterfaceEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/cop_whitelist_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(CopWhitelistEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.CopWhitelistEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/cop/cop_rpc.ba.go b/binapi/cop/cop_rpc.ba.go
index 2768c23..120613d 100644
--- a/binapi/cop/cop_rpc.ba.go
+++ b/binapi/cop/cop_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  cop.
+// RPCService defines RPC service cop.
 type RPCService interface {
 	CopInterfaceEnableDisable(ctx context.Context, in *CopInterfaceEnableDisable) (*CopInterfaceEnableDisableReply, error)
 	CopWhitelistEnableDisable(ctx context.Context, in *CopWhitelistEnableDisable) (*CopWhitelistEnableDisableReply, error)
@@ -28,7 +28,7 @@ func (c *serviceClient) CopInterfaceEnableDisable(ctx context.Context, in *CopIn
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) CopWhitelistEnableDisable(ctx context.Context, in *CopWhitelistEnableDisable) (*CopWhitelistEnableDisableReply, error) {
@@ -37,5 +37,5 @@ func (c *serviceClient) CopWhitelistEnableDisable(ctx context.Context, in *CopWh
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ct6/ct6.ba.go b/binapi/ct6/ct6.ba.go
index 5dc6097..40394db 100644
--- a/binapi/ct6/ct6.ba.go
+++ b/binapi/ct6/ct6.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/ct6.api.json
 
 // Package ct6 contains generated bindings for API file ct6.api.
diff --git a/binapi/ct6/ct6_rest.ba.go b/binapi/ct6/ct6_rest.ba.go
deleted file mode 100644
index a3ffcde..0000000
--- a/binapi/ct6/ct6_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ct6
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ct6_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ct6EnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ct6EnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ct6/ct6_rpc.ba.go b/binapi/ct6/ct6_rpc.ba.go
index d165339..fcae22d 100644
--- a/binapi/ct6/ct6_rpc.ba.go
+++ b/binapi/ct6/ct6_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  ct6.
+// RPCService defines RPC service ct6.
 type RPCService interface {
 	Ct6EnableDisable(ctx context.Context, in *Ct6EnableDisable) (*Ct6EnableDisableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) Ct6EnableDisable(ctx context.Context, in *Ct6EnableDisab
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/dhcp/dhcp.ba.go b/binapi/dhcp/dhcp.ba.go
index 4adc88b..db84847 100644
--- a/binapi/dhcp/dhcp.ba.go
+++ b/binapi/dhcp/dhcp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/dhcp.api.json
 
 // Package dhcp contains generated bindings for API file dhcp.api.
diff --git a/binapi/dhcp/dhcp_rest.ba.go b/binapi/dhcp/dhcp_rest.ba.go
deleted file mode 100644
index 4a4d9d1..0000000
--- a/binapi/dhcp/dhcp_rest.ba.go
+++ /dev/null
@@ -1,249 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package dhcp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/dhcp6_clients_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCP6ClientsEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DHCP6ClientsEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dhcp6_duid_ll_set", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCP6DuidLlSet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DHCP6DuidLlSet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dhcp6_pd_send_client_message", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCP6PdSendClientMessage)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DHCP6PdSendClientMessage(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dhcp6_send_client_message", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCP6SendClientMessage)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DHCP6SendClientMessage(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dhcp_client_config", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCPClientConfig)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DHCPClientConfig(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dhcp_plugin_control_ping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCPPluginControlPing)
-		reply, err := rpc.DHCPPluginControlPing(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dhcp_plugin_get_version", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCPPluginGetVersion)
-		reply, err := rpc.DHCPPluginGetVersion(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dhcp_proxy_config", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCPProxyConfig)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DHCPProxyConfig(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dhcp_proxy_set_vss", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCPProxySetVss)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DHCPProxySetVss(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/want_dhcp6_pd_reply_events", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(WantDHCP6PdReplyEvents)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.WantDHCP6PdReplyEvents(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/want_dhcp6_reply_events", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(WantDHCP6ReplyEvents)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.WantDHCP6ReplyEvents(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/dhcp/dhcp_rpc.ba.go b/binapi/dhcp/dhcp_rpc.ba.go
index 384fc9a..6309d8e 100644
--- a/binapi/dhcp/dhcp_rpc.ba.go
+++ b/binapi/dhcp/dhcp_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  dhcp.
+// RPCService defines RPC service dhcp.
 type RPCService interface {
 	DHCP6ClientsEnableDisable(ctx context.Context, in *DHCP6ClientsEnableDisable) (*DHCP6ClientsEnableDisableReply, error)
 	DHCP6DuidLlSet(ctx context.Context, in *DHCP6DuidLlSet) (*DHCP6DuidLlSetReply, error)
@@ -42,7 +42,7 @@ func (c *serviceClient) DHCP6ClientsEnableDisable(ctx context.Context, in *DHCP6
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DHCP6DuidLlSet(ctx context.Context, in *DHCP6DuidLlSet) (*DHCP6DuidLlSetReply, error) {
@@ -51,7 +51,7 @@ func (c *serviceClient) DHCP6DuidLlSet(ctx context.Context, in *DHCP6DuidLlSet)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DHCP6PdSendClientMessage(ctx context.Context, in *DHCP6PdSendClientMessage) (*DHCP6PdSendClientMessageReply, error) {
@@ -60,7 +60,7 @@ func (c *serviceClient) DHCP6PdSendClientMessage(ctx context.Context, in *DHCP6P
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DHCP6SendClientMessage(ctx context.Context, in *DHCP6SendClientMessage) (*DHCP6SendClientMessageReply, error) {
@@ -69,7 +69,7 @@ func (c *serviceClient) DHCP6SendClientMessage(ctx context.Context, in *DHCP6Sen
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DHCPClientConfig(ctx context.Context, in *DHCPClientConfig) (*DHCPClientConfigReply, error) {
@@ -78,7 +78,7 @@ func (c *serviceClient) DHCPClientConfig(ctx context.Context, in *DHCPClientConf
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DHCPClientDump(ctx context.Context, in *DHCPClientDump) (RPCService_DHCPClientDumpClient, error) {
@@ -126,7 +126,7 @@ func (c *serviceClient) DHCPPluginControlPing(ctx context.Context, in *DHCPPlugi
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DHCPPluginGetVersion(ctx context.Context, in *DHCPPluginGetVersion) (*DHCPPluginGetVersionReply, error) {
@@ -144,7 +144,7 @@ func (c *serviceClient) DHCPProxyConfig(ctx context.Context, in *DHCPProxyConfig
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DHCPProxyDump(ctx context.Context, in *DHCPProxyDump) (RPCService_DHCPProxyDumpClient, error) {
@@ -192,7 +192,7 @@ func (c *serviceClient) DHCPProxySetVss(ctx context.Context, in *DHCPProxySetVss
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) WantDHCP6PdReplyEvents(ctx context.Context, in *WantDHCP6PdReplyEvents) (*WantDHCP6PdReplyEventsReply, error) {
@@ -201,7 +201,7 @@ func (c *serviceClient) WantDHCP6PdReplyEvents(ctx context.Context, in *WantDHCP
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) WantDHCP6ReplyEvents(ctx context.Context, in *WantDHCP6ReplyEvents) (*WantDHCP6ReplyEventsReply, error) {
@@ -210,5 +210,5 @@ func (c *serviceClient) WantDHCP6ReplyEvents(ctx context.Context, in *WantDHCP6R
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp.ba.go b/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp.ba.go
index 4fcb012..ca4f01d 100644
--- a/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp.ba.go
+++ b/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/dhcp6_ia_na_client_cp.api.json
 
 // Package dhcp6_ia_na_client_cp contains generated bindings for API file dhcp6_ia_na_client_cp.api.
diff --git a/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp_rest.ba.go b/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp_rest.ba.go
deleted file mode 100644
index 0fd5ce2..0000000
--- a/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package dhcp6_ia_na_client_cp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/dhcp6_client_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCP6ClientEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DHCP6ClientEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp_rpc.ba.go b/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp_rpc.ba.go
index 1083167..3fbf238 100644
--- a/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp_rpc.ba.go
+++ b/binapi/dhcp6_ia_na_client_cp/dhcp6_ia_na_client_cp_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  dhcp6_ia_na_client_cp.
+// RPCService defines RPC service dhcp6_ia_na_client_cp.
 type RPCService interface {
 	DHCP6ClientEnableDisable(ctx context.Context, in *DHCP6ClientEnableDisable) (*DHCP6ClientEnableDisableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) DHCP6ClientEnableDisable(ctx context.Context, in *DHCP6C
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp.ba.go b/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp.ba.go
index 7e4e2bb..f5690d1 100644
--- a/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp.ba.go
+++ b/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/dhcp6_pd_client_cp.api.json
 
 // Package dhcp6_pd_client_cp contains generated bindings for API file dhcp6_pd_client_cp.api.
diff --git a/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp_rest.ba.go b/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp_rest.ba.go
deleted file mode 100644
index fa76aa8..0000000
--- a/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package dhcp6_pd_client_cp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/dhcp6_pd_client_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DHCP6PdClientEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DHCP6PdClientEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip6_add_del_address_using_prefix", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IP6AddDelAddressUsingPrefix)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IP6AddDelAddressUsingPrefix(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp_rpc.ba.go b/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp_rpc.ba.go
index 670e012..f531408 100644
--- a/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp_rpc.ba.go
+++ b/binapi/dhcp6_pd_client_cp/dhcp6_pd_client_cp_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  dhcp6_pd_client_cp.
+// RPCService defines RPC service dhcp6_pd_client_cp.
 type RPCService interface {
 	DHCP6PdClientEnableDisable(ctx context.Context, in *DHCP6PdClientEnableDisable) (*DHCP6PdClientEnableDisableReply, error)
 	IP6AddDelAddressUsingPrefix(ctx context.Context, in *IP6AddDelAddressUsingPrefix) (*IP6AddDelAddressUsingPrefixReply, error)
@@ -28,7 +28,7 @@ func (c *serviceClient) DHCP6PdClientEnableDisable(ctx context.Context, in *DHCP
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IP6AddDelAddressUsingPrefix(ctx context.Context, in *IP6AddDelAddressUsingPrefix) (*IP6AddDelAddressUsingPrefixReply, error) {
@@ -37,5 +37,5 @@ func (c *serviceClient) IP6AddDelAddressUsingPrefix(ctx context.Context, in *IP6
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/dns/dns.ba.go b/binapi/dns/dns.ba.go
index fc2324c..8ebb3bf 100644
--- a/binapi/dns/dns.ba.go
+++ b/binapi/dns/dns.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/dns.api.json
 
 // Package dns contains generated bindings for API file dns.api.
diff --git a/binapi/dns/dns_rest.ba.go b/binapi/dns/dns_rest.ba.go
deleted file mode 100644
index e67d971..0000000
--- a/binapi/dns/dns_rest.ba.go
+++ /dev/null
@@ -1,106 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package dns
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/dns_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DNSEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DNSEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dns_name_server_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DNSNameServerAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DNSNameServerAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dns_resolve_ip", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DNSResolveIP)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DNSResolveIP(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dns_resolve_name", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DNSResolveName)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DNSResolveName(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/dns/dns_rpc.ba.go b/binapi/dns/dns_rpc.ba.go
index 6bf3622..deb5be8 100644
--- a/binapi/dns/dns_rpc.ba.go
+++ b/binapi/dns/dns_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  dns.
+// RPCService defines RPC service dns.
 type RPCService interface {
 	DNSEnableDisable(ctx context.Context, in *DNSEnableDisable) (*DNSEnableDisableReply, error)
 	DNSNameServerAddDel(ctx context.Context, in *DNSNameServerAddDel) (*DNSNameServerAddDelReply, error)
@@ -30,7 +30,7 @@ func (c *serviceClient) DNSEnableDisable(ctx context.Context, in *DNSEnableDisab
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DNSNameServerAddDel(ctx context.Context, in *DNSNameServerAddDel) (*DNSNameServerAddDelReply, error) {
@@ -39,7 +39,7 @@ func (c *serviceClient) DNSNameServerAddDel(ctx context.Context, in *DNSNameServ
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DNSResolveIP(ctx context.Context, in *DNSResolveIP) (*DNSResolveIPReply, error) {
@@ -48,7 +48,7 @@ func (c *serviceClient) DNSResolveIP(ctx context.Context, in *DNSResolveIP) (*DN
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DNSResolveName(ctx context.Context, in *DNSResolveName) (*DNSResolveNameReply, error) {
@@ -57,5 +57,5 @@ func (c *serviceClient) DNSResolveName(ctx context.Context, in *DNSResolveName)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/dslite/dslite.ba.go b/binapi/dslite/dslite.ba.go
index efcf240..0837892 100644
--- a/binapi/dslite/dslite.ba.go
+++ b/binapi/dslite/dslite.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/dslite.api.json
 
 // Package dslite contains generated bindings for API file dslite.api.
diff --git a/binapi/dslite/dslite_rest.ba.go b/binapi/dslite/dslite_rest.ba.go
deleted file mode 100644
index eba86b0..0000000
--- a/binapi/dslite/dslite_rest.ba.go
+++ /dev/null
@@ -1,111 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package dslite
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/dslite_add_del_pool_addr_range", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DsliteAddDelPoolAddrRange)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DsliteAddDelPoolAddrRange(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dslite_get_aftr_addr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DsliteGetAftrAddr)
-		reply, err := rpc.DsliteGetAftrAddr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dslite_get_b4_addr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DsliteGetB4Addr)
-		reply, err := rpc.DsliteGetB4Addr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dslite_set_aftr_addr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DsliteSetAftrAddr)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DsliteSetAftrAddr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/dslite_set_b4_addr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DsliteSetB4Addr)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DsliteSetB4Addr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/dslite/dslite_rpc.ba.go b/binapi/dslite/dslite_rpc.ba.go
index 6314fd2..5847cf6 100644
--- a/binapi/dslite/dslite_rpc.ba.go
+++ b/binapi/dslite/dslite_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  dslite.
+// RPCService defines RPC service dslite.
 type RPCService interface {
 	DsliteAddDelPoolAddrRange(ctx context.Context, in *DsliteAddDelPoolAddrRange) (*DsliteAddDelPoolAddrRangeReply, error)
 	DsliteAddressDump(ctx context.Context, in *DsliteAddressDump) (RPCService_DsliteAddressDumpClient, error)
@@ -35,7 +35,7 @@ func (c *serviceClient) DsliteAddDelPoolAddrRange(ctx context.Context, in *Dslit
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DsliteAddressDump(ctx context.Context, in *DsliteAddressDump) (RPCService_DsliteAddressDumpClient, error) {
@@ -83,7 +83,7 @@ func (c *serviceClient) DsliteGetAftrAddr(ctx context.Context, in *DsliteGetAftr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DsliteGetB4Addr(ctx context.Context, in *DsliteGetB4Addr) (*DsliteGetB4AddrReply, error) {
@@ -92,7 +92,7 @@ func (c *serviceClient) DsliteGetB4Addr(ctx context.Context, in *DsliteGetB4Addr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DsliteSetAftrAddr(ctx context.Context, in *DsliteSetAftrAddr) (*DsliteSetAftrAddrReply, error) {
@@ -101,7 +101,7 @@ func (c *serviceClient) DsliteSetAftrAddr(ctx context.Context, in *DsliteSetAftr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DsliteSetB4Addr(ctx context.Context, in *DsliteSetB4Addr) (*DsliteSetB4AddrReply, error) {
@@ -110,5 +110,5 @@ func (c *serviceClient) DsliteSetB4Addr(ctx context.Context, in *DsliteSetB4Addr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ethernet_types/ethernet_types.ba.go b/binapi/ethernet_types/ethernet_types.ba.go
index 63b1034..5956376 100644
--- a/binapi/ethernet_types/ethernet_types.ba.go
+++ b/binapi/ethernet_types/ethernet_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/ethernet_types.api.json
 
 // Package ethernet_types contains generated bindings for API file ethernet_types.api.
diff --git a/binapi/feature/feature.ba.go b/binapi/feature/feature.ba.go
index cc54364..db5cafc 100644
--- a/binapi/feature/feature.ba.go
+++ b/binapi/feature/feature.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/feature.api.json
 
 // Package feature contains generated bindings for API file feature.api.
diff --git a/binapi/feature/feature_rest.ba.go b/binapi/feature/feature_rest.ba.go
deleted file mode 100644
index a1b0604..0000000
--- a/binapi/feature/feature_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package feature
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/feature_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(FeatureEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.FeatureEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/feature/feature_rpc.ba.go b/binapi/feature/feature_rpc.ba.go
index 6c42e4f..811934b 100644
--- a/binapi/feature/feature_rpc.ba.go
+++ b/binapi/feature/feature_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  feature.
+// RPCService defines RPC service feature.
 type RPCService interface {
 	FeatureEnableDisable(ctx context.Context, in *FeatureEnableDisable) (*FeatureEnableDisableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) FeatureEnableDisable(ctx context.Context, in *FeatureEna
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/fib_types/fib_types.ba.go b/binapi/fib_types/fib_types.ba.go
index 3194edf..1fcf29e 100644
--- a/binapi/fib_types/fib_types.ba.go
+++ b/binapi/fib_types/fib_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/fib_types.api.json
 
 // Package fib_types contains generated bindings for API file fib_types.api.
diff --git a/binapi/flowprobe/flowprobe.ba.go b/binapi/flowprobe/flowprobe.ba.go
index b158c6d..3082b52 100644
--- a/binapi/flowprobe/flowprobe.ba.go
+++ b/binapi/flowprobe/flowprobe.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/flowprobe.api.json
 
 // Package flowprobe contains generated bindings for API file flowprobe.api.
diff --git a/binapi/flowprobe/flowprobe_rest.ba.go b/binapi/flowprobe/flowprobe_rest.ba.go
deleted file mode 100644
index 3de76b9..0000000
--- a/binapi/flowprobe/flowprobe_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package flowprobe
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/flowprobe_params", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(FlowprobeParams)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.FlowprobeParams(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/flowprobe_tx_interface_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(FlowprobeTxInterfaceAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.FlowprobeTxInterfaceAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/flowprobe/flowprobe_rpc.ba.go b/binapi/flowprobe/flowprobe_rpc.ba.go
index 97520fd..3b0178d 100644
--- a/binapi/flowprobe/flowprobe_rpc.ba.go
+++ b/binapi/flowprobe/flowprobe_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  flowprobe.
+// RPCService defines RPC service flowprobe.
 type RPCService interface {
 	FlowprobeParams(ctx context.Context, in *FlowprobeParams) (*FlowprobeParamsReply, error)
 	FlowprobeTxInterfaceAddDel(ctx context.Context, in *FlowprobeTxInterfaceAddDel) (*FlowprobeTxInterfaceAddDelReply, error)
@@ -28,7 +28,7 @@ func (c *serviceClient) FlowprobeParams(ctx context.Context, in *FlowprobeParams
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) FlowprobeTxInterfaceAddDel(ctx context.Context, in *FlowprobeTxInterfaceAddDel) (*FlowprobeTxInterfaceAddDelReply, error) {
@@ -37,5 +37,5 @@ func (c *serviceClient) FlowprobeTxInterfaceAddDel(ctx context.Context, in *Flow
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/gbp/gbp.ba.go b/binapi/gbp/gbp.ba.go
index 066371a..efa1bbc 100644
--- a/binapi/gbp/gbp.ba.go
+++ b/binapi/gbp/gbp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/gbp.api.json
 
 // Package gbp contains generated bindings for API file gbp.api.
diff --git a/binapi/gbp/gbp_rest.ba.go b/binapi/gbp/gbp_rest.ba.go
deleted file mode 100644
index 9999a07..0000000
--- a/binapi/gbp/gbp_rest.ba.go
+++ /dev/null
@@ -1,336 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package gbp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/gbp_bridge_domain_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpBridgeDomainAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpBridgeDomainAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_bridge_domain_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpBridgeDomainDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpBridgeDomainDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_contract_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpContractAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpContractAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_endpoint_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpEndpointAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpEndpointAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_endpoint_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpEndpointDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpEndpointDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_endpoint_group_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpEndpointGroupAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpEndpointGroupAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_endpoint_group_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpEndpointGroupDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpEndpointGroupDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_ext_itf_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpExtItfAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpExtItfAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_recirc_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpRecircAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpRecircAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_route_domain_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpRouteDomainAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpRouteDomainAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_route_domain_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpRouteDomainDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpRouteDomainDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_subnet_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpSubnetAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpSubnetAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_vxlan_tunnel_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpVxlanTunnelAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpVxlanTunnelAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gbp_vxlan_tunnel_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GbpVxlanTunnelDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GbpVxlanTunnelDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/gbp/gbp_rpc.ba.go b/binapi/gbp/gbp_rpc.ba.go
index 635394e..4b45ea7 100644
--- a/binapi/gbp/gbp_rpc.ba.go
+++ b/binapi/gbp/gbp_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  gbp.
+// RPCService defines RPC service gbp.
 type RPCService interface {
 	GbpBridgeDomainAdd(ctx context.Context, in *GbpBridgeDomainAdd) (*GbpBridgeDomainAddReply, error)
 	GbpBridgeDomainDel(ctx context.Context, in *GbpBridgeDomainDel) (*GbpBridgeDomainDelReply, error)
@@ -52,7 +52,7 @@ func (c *serviceClient) GbpBridgeDomainAdd(ctx context.Context, in *GbpBridgeDom
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpBridgeDomainDel(ctx context.Context, in *GbpBridgeDomainDel) (*GbpBridgeDomainDelReply, error) {
@@ -61,7 +61,7 @@ func (c *serviceClient) GbpBridgeDomainDel(ctx context.Context, in *GbpBridgeDom
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpBridgeDomainDump(ctx context.Context, in *GbpBridgeDomainDump) (RPCService_GbpBridgeDomainDumpClient, error) {
@@ -109,7 +109,7 @@ func (c *serviceClient) GbpContractAddDel(ctx context.Context, in *GbpContractAd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpContractDump(ctx context.Context, in *GbpContractDump) (RPCService_GbpContractDumpClient, error) {
@@ -157,7 +157,7 @@ func (c *serviceClient) GbpEndpointAdd(ctx context.Context, in *GbpEndpointAdd)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpEndpointDel(ctx context.Context, in *GbpEndpointDel) (*GbpEndpointDelReply, error) {
@@ -166,7 +166,7 @@ func (c *serviceClient) GbpEndpointDel(ctx context.Context, in *GbpEndpointDel)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpEndpointDump(ctx context.Context, in *GbpEndpointDump) (RPCService_GbpEndpointDumpClient, error) {
@@ -214,7 +214,7 @@ func (c *serviceClient) GbpEndpointGroupAdd(ctx context.Context, in *GbpEndpoint
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpEndpointGroupDel(ctx context.Context, in *GbpEndpointGroupDel) (*GbpEndpointGroupDelReply, error) {
@@ -223,7 +223,7 @@ func (c *serviceClient) GbpEndpointGroupDel(ctx context.Context, in *GbpEndpoint
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpEndpointGroupDump(ctx context.Context, in *GbpEndpointGroupDump) (RPCService_GbpEndpointGroupDumpClient, error) {
@@ -271,7 +271,7 @@ func (c *serviceClient) GbpExtItfAddDel(ctx context.Context, in *GbpExtItfAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpExtItfDump(ctx context.Context, in *GbpExtItfDump) (RPCService_GbpExtItfDumpClient, error) {
@@ -319,7 +319,7 @@ func (c *serviceClient) GbpRecircAddDel(ctx context.Context, in *GbpRecircAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpRecircDump(ctx context.Context, in *GbpRecircDump) (RPCService_GbpRecircDumpClient, error) {
@@ -367,7 +367,7 @@ func (c *serviceClient) GbpRouteDomainAdd(ctx context.Context, in *GbpRouteDomai
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpRouteDomainDel(ctx context.Context, in *GbpRouteDomainDel) (*GbpRouteDomainDelReply, error) {
@@ -376,7 +376,7 @@ func (c *serviceClient) GbpRouteDomainDel(ctx context.Context, in *GbpRouteDomai
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpRouteDomainDump(ctx context.Context, in *GbpRouteDomainDump) (RPCService_GbpRouteDomainDumpClient, error) {
@@ -424,7 +424,7 @@ func (c *serviceClient) GbpSubnetAddDel(ctx context.Context, in *GbpSubnetAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpSubnetDump(ctx context.Context, in *GbpSubnetDump) (RPCService_GbpSubnetDumpClient, error) {
@@ -472,7 +472,7 @@ func (c *serviceClient) GbpVxlanTunnelAdd(ctx context.Context, in *GbpVxlanTunne
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpVxlanTunnelDel(ctx context.Context, in *GbpVxlanTunnelDel) (*GbpVxlanTunnelDelReply, error) {
@@ -481,7 +481,7 @@ func (c *serviceClient) GbpVxlanTunnelDel(ctx context.Context, in *GbpVxlanTunne
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GbpVxlanTunnelDump(ctx context.Context, in *GbpVxlanTunnelDump) (RPCService_GbpVxlanTunnelDumpClient, error) {
diff --git a/binapi/gen.go b/binapi/gen.go
index aefde2b..eec87da 100644
--- a/binapi/gen.go
+++ b/binapi/gen.go
@@ -18,4 +18,4 @@ package binapi
 //
 //     go generate ./binapi
 //
-//go:generate binapi-generator -input-dir=/usr/share/vpp/api -output-dir=. -gen=rpc,rest
+//go:generate binapi-generator -input-dir=/usr/share/vpp/api -output-dir=. -gen=rpc
diff --git a/binapi/geneve/geneve.ba.go b/binapi/geneve/geneve.ba.go
index fcd512d..58c5988 100644
--- a/binapi/geneve/geneve.ba.go
+++ b/binapi/geneve/geneve.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/geneve.api.json
 
 // Package geneve contains generated bindings for API file geneve.api.
diff --git a/binapi/geneve/geneve_rest.ba.go b/binapi/geneve/geneve_rest.ba.go
deleted file mode 100644
index 4987b1d..0000000
--- a/binapi/geneve/geneve_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package geneve
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/geneve_add_del_tunnel", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GeneveAddDelTunnel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GeneveAddDelTunnel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_geneve_bypass", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetGeneveBypass)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetGeneveBypass(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/geneve/geneve_rpc.ba.go b/binapi/geneve/geneve_rpc.ba.go
index 88f7aac..f2dacb8 100644
--- a/binapi/geneve/geneve_rpc.ba.go
+++ b/binapi/geneve/geneve_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  geneve.
+// RPCService defines RPC service geneve.
 type RPCService interface {
 	GeneveAddDelTunnel(ctx context.Context, in *GeneveAddDelTunnel) (*GeneveAddDelTunnelReply, error)
 	GeneveTunnelDump(ctx context.Context, in *GeneveTunnelDump) (RPCService_GeneveTunnelDumpClient, error)
@@ -32,7 +32,7 @@ func (c *serviceClient) GeneveAddDelTunnel(ctx context.Context, in *GeneveAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GeneveTunnelDump(ctx context.Context, in *GeneveTunnelDump) (RPCService_GeneveTunnelDumpClient, error) {
@@ -80,5 +80,5 @@ func (c *serviceClient) SwInterfaceSetGeneveBypass(ctx context.Context, in *SwIn
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/gre/gre.ba.go b/binapi/gre/gre.ba.go
index 9fa68cb..4c0b9c0 100644
--- a/binapi/gre/gre.ba.go
+++ b/binapi/gre/gre.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/gre.api.json
 
 // Package gre contains generated bindings for API file gre.api.
diff --git a/binapi/gre/gre_rest.ba.go b/binapi/gre/gre_rest.ba.go
deleted file mode 100644
index d344aa8..0000000
--- a/binapi/gre/gre_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package gre
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/gre_tunnel_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GreTunnelAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GreTunnelAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/gre/gre_rpc.ba.go b/binapi/gre/gre_rpc.ba.go
index 670aeec..f68ef46 100644
--- a/binapi/gre/gre_rpc.ba.go
+++ b/binapi/gre/gre_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  gre.
+// RPCService defines RPC service gre.
 type RPCService interface {
 	GreTunnelAddDel(ctx context.Context, in *GreTunnelAddDel) (*GreTunnelAddDelReply, error)
 	GreTunnelDump(ctx context.Context, in *GreTunnelDump) (RPCService_GreTunnelDumpClient, error)
@@ -31,7 +31,7 @@ func (c *serviceClient) GreTunnelAddDel(ctx context.Context, in *GreTunnelAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GreTunnelDump(ctx context.Context, in *GreTunnelDump) (RPCService_GreTunnelDumpClient, error) {
diff --git a/binapi/gso/gso.ba.go b/binapi/gso/gso.ba.go
index 78e7536..f243772 100644
--- a/binapi/gso/gso.ba.go
+++ b/binapi/gso/gso.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/gso.api.json
 
 // Package gso contains generated bindings for API file gso.api.
diff --git a/binapi/gso/gso_rest.ba.go b/binapi/gso/gso_rest.ba.go
deleted file mode 100644
index d04c3bd..0000000
--- a/binapi/gso/gso_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package gso
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/feature_gso_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(FeatureGsoEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.FeatureGsoEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/gso/gso_rpc.ba.go b/binapi/gso/gso_rpc.ba.go
index 42bb837..0d3ed10 100644
--- a/binapi/gso/gso_rpc.ba.go
+++ b/binapi/gso/gso_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  gso.
+// RPCService defines RPC service gso.
 type RPCService interface {
 	FeatureGsoEnableDisable(ctx context.Context, in *FeatureGsoEnableDisable) (*FeatureGsoEnableDisableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) FeatureGsoEnableDisable(ctx context.Context, in *Feature
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/gtpu/gtpu.ba.go b/binapi/gtpu/gtpu.ba.go
index 96ae51f..5d2a038 100644
--- a/binapi/gtpu/gtpu.ba.go
+++ b/binapi/gtpu/gtpu.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/gtpu.api.json
 
 // Package gtpu contains generated bindings for API file gtpu.api.
diff --git a/binapi/gtpu/gtpu_rest.ba.go b/binapi/gtpu/gtpu_rest.ba.go
deleted file mode 100644
index 6631cd8..0000000
--- a/binapi/gtpu/gtpu_rest.ba.go
+++ /dev/null
@@ -1,83 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package gtpu
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/gtpu_add_del_tunnel", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GtpuAddDelTunnel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GtpuAddDelTunnel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gtpu_offload_rx", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GtpuOffloadRx)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GtpuOffloadRx(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_gtpu_bypass", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetGtpuBypass)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetGtpuBypass(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/gtpu/gtpu_rpc.ba.go b/binapi/gtpu/gtpu_rpc.ba.go
index d5f3263..46a7e7d 100644
--- a/binapi/gtpu/gtpu_rpc.ba.go
+++ b/binapi/gtpu/gtpu_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  gtpu.
+// RPCService defines RPC service gtpu.
 type RPCService interface {
 	GtpuAddDelTunnel(ctx context.Context, in *GtpuAddDelTunnel) (*GtpuAddDelTunnelReply, error)
 	GtpuOffloadRx(ctx context.Context, in *GtpuOffloadRx) (*GtpuOffloadRxReply, error)
@@ -33,7 +33,7 @@ func (c *serviceClient) GtpuAddDelTunnel(ctx context.Context, in *GtpuAddDelTunn
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GtpuOffloadRx(ctx context.Context, in *GtpuOffloadRx) (*GtpuOffloadRxReply, error) {
@@ -42,7 +42,7 @@ func (c *serviceClient) GtpuOffloadRx(ctx context.Context, in *GtpuOffloadRx) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GtpuTunnelDump(ctx context.Context, in *GtpuTunnelDump) (RPCService_GtpuTunnelDumpClient, error) {
@@ -90,5 +90,5 @@ func (c *serviceClient) SwInterfaceSetGtpuBypass(ctx context.Context, in *SwInte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/http_static/http_static.ba.go b/binapi/http_static/http_static.ba.go
index 2116a8b..811bb0d 100644
--- a/binapi/http_static/http_static.ba.go
+++ b/binapi/http_static/http_static.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/http_static.api.json
 
 // Package http_static contains generated bindings for API file http_static.api.
diff --git a/binapi/http_static/http_static_rest.ba.go b/binapi/http_static/http_static_rest.ba.go
deleted file mode 100644
index f488f5a..0000000
--- a/binapi/http_static/http_static_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package http_static
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/http_static_enable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(HTTPStaticEnable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.HTTPStaticEnable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/http_static/http_static_rpc.ba.go b/binapi/http_static/http_static_rpc.ba.go
index 67329dd..12bd4c1 100644
--- a/binapi/http_static/http_static_rpc.ba.go
+++ b/binapi/http_static/http_static_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  http_static.
+// RPCService defines RPC service http_static.
 type RPCService interface {
 	HTTPStaticEnable(ctx context.Context, in *HTTPStaticEnable) (*HTTPStaticEnableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) HTTPStaticEnable(ctx context.Context, in *HTTPStaticEnab
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/igmp/igmp.ba.go b/binapi/igmp/igmp.ba.go
index a43b599..2bbe575 100644
--- a/binapi/igmp/igmp.ba.go
+++ b/binapi/igmp/igmp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/igmp.api.json
 
 // Package igmp contains generated bindings for API file igmp.api.
diff --git a/binapi/igmp/igmp_rest.ba.go b/binapi/igmp/igmp_rest.ba.go
deleted file mode 100644
index c3869ff..0000000
--- a/binapi/igmp/igmp_rest.ba.go
+++ /dev/null
@@ -1,175 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package igmp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/igmp_clear_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IgmpClearInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IgmpClearInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/igmp_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IgmpEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IgmpEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/igmp_group_prefix_set", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IgmpGroupPrefixSet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IgmpGroupPrefixSet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/igmp_listen", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IgmpListen)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IgmpListen(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/igmp_proxy_device_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IgmpProxyDeviceAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IgmpProxyDeviceAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/igmp_proxy_device_add_del_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IgmpProxyDeviceAddDelInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IgmpProxyDeviceAddDelInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/want_igmp_events", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(WantIgmpEvents)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.WantIgmpEvents(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/igmp/igmp_rpc.ba.go b/binapi/igmp/igmp_rpc.ba.go
index c1ef9e5..3cda04c 100644
--- a/binapi/igmp/igmp_rpc.ba.go
+++ b/binapi/igmp/igmp_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  igmp.
+// RPCService defines RPC service igmp.
 type RPCService interface {
 	IgmpClearInterface(ctx context.Context, in *IgmpClearInterface) (*IgmpClearInterfaceReply, error)
 	IgmpDump(ctx context.Context, in *IgmpDump) (RPCService_IgmpDumpClient, error)
@@ -38,7 +38,7 @@ func (c *serviceClient) IgmpClearInterface(ctx context.Context, in *IgmpClearInt
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IgmpDump(ctx context.Context, in *IgmpDump) (RPCService_IgmpDumpClient, error) {
@@ -86,7 +86,7 @@ func (c *serviceClient) IgmpEnableDisable(ctx context.Context, in *IgmpEnableDis
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IgmpGroupPrefixDump(ctx context.Context, in *IgmpGroupPrefixDump) (RPCService_IgmpGroupPrefixDumpClient, error) {
@@ -134,7 +134,7 @@ func (c *serviceClient) IgmpGroupPrefixSet(ctx context.Context, in *IgmpGroupPre
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IgmpListen(ctx context.Context, in *IgmpListen) (*IgmpListenReply, error) {
@@ -143,7 +143,7 @@ func (c *serviceClient) IgmpListen(ctx context.Context, in *IgmpListen) (*IgmpLi
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IgmpProxyDeviceAddDel(ctx context.Context, in *IgmpProxyDeviceAddDel) (*IgmpProxyDeviceAddDelReply, error) {
@@ -152,7 +152,7 @@ func (c *serviceClient) IgmpProxyDeviceAddDel(ctx context.Context, in *IgmpProxy
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IgmpProxyDeviceAddDelInterface(ctx context.Context, in *IgmpProxyDeviceAddDelInterface) (*IgmpProxyDeviceAddDelInterfaceReply, error) {
@@ -161,7 +161,7 @@ func (c *serviceClient) IgmpProxyDeviceAddDelInterface(ctx context.Context, in *
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) WantIgmpEvents(ctx context.Context, in *WantIgmpEvents) (*WantIgmpEventsReply, error) {
@@ -170,5 +170,5 @@ func (c *serviceClient) WantIgmpEvents(ctx context.Context, in *WantIgmpEvents)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ikev2/ikev2.ba.go b/binapi/ikev2/ikev2.ba.go
index 5fc68c3..8313ece 100644
--- a/binapi/ikev2/ikev2.ba.go
+++ b/binapi/ikev2/ikev2.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/ikev2.api.json
 
 // Package ikev2 contains generated bindings for API file ikev2.api.
diff --git a/binapi/ikev2/ikev2_rest.ba.go b/binapi/ikev2/ikev2_rest.ba.go
deleted file mode 100644
index 9ffdffa..0000000
--- a/binapi/ikev2/ikev2_rest.ba.go
+++ /dev/null
@@ -1,419 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ikev2
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ikev2_initiate_del_child_sa", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2InitiateDelChildSa)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2InitiateDelChildSa(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_initiate_del_ike_sa", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2InitiateDelIkeSa)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2InitiateDelIkeSa(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_initiate_rekey_child_sa", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2InitiateRekeyChildSa)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2InitiateRekeyChildSa(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_initiate_sa_init", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2InitiateSaInit)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2InitiateSaInit(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_plugin_get_version", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2PluginGetVersion)
-		reply, err := rpc.Ikev2PluginGetVersion(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_profile_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2ProfileAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2ProfileAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_profile_set_auth", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2ProfileSetAuth)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2ProfileSetAuth(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_profile_set_id", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2ProfileSetID)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2ProfileSetID(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_profile_set_ipsec_udp_port", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2ProfileSetIpsecUDPPort)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2ProfileSetIpsecUDPPort(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_profile_set_liveness", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2ProfileSetLiveness)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2ProfileSetLiveness(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_profile_set_ts", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2ProfileSetTs)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2ProfileSetTs(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_profile_set_udp_encap", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2ProfileSetUDPEncap)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2ProfileSetUDPEncap(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_set_esp_transforms", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2SetEspTransforms)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2SetEspTransforms(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_set_ike_transforms", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2SetIkeTransforms)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2SetIkeTransforms(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_set_local_key", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2SetLocalKey)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2SetLocalKey(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_set_responder", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2SetResponder)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2SetResponder(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_set_sa_lifetime", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2SetSaLifetime)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2SetSaLifetime(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ikev2_set_tunnel_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ikev2SetTunnelInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ikev2SetTunnelInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ikev2/ikev2_rpc.ba.go b/binapi/ikev2/ikev2_rpc.ba.go
index 3491c54..955c440 100644
--- a/binapi/ikev2/ikev2_rpc.ba.go
+++ b/binapi/ikev2/ikev2_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  ikev2.
+// RPCService defines RPC service ikev2.
 type RPCService interface {
 	Ikev2InitiateDelChildSa(ctx context.Context, in *Ikev2InitiateDelChildSa) (*Ikev2InitiateDelChildSaReply, error)
 	Ikev2InitiateDelIkeSa(ctx context.Context, in *Ikev2InitiateDelIkeSa) (*Ikev2InitiateDelIkeSaReply, error)
@@ -44,7 +44,7 @@ func (c *serviceClient) Ikev2InitiateDelChildSa(ctx context.Context, in *Ikev2In
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2InitiateDelIkeSa(ctx context.Context, in *Ikev2InitiateDelIkeSa) (*Ikev2InitiateDelIkeSaReply, error) {
@@ -53,7 +53,7 @@ func (c *serviceClient) Ikev2InitiateDelIkeSa(ctx context.Context, in *Ikev2Init
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2InitiateRekeyChildSa(ctx context.Context, in *Ikev2InitiateRekeyChildSa) (*Ikev2InitiateRekeyChildSaReply, error) {
@@ -62,7 +62,7 @@ func (c *serviceClient) Ikev2InitiateRekeyChildSa(ctx context.Context, in *Ikev2
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2InitiateSaInit(ctx context.Context, in *Ikev2InitiateSaInit) (*Ikev2InitiateSaInitReply, error) {
@@ -71,7 +71,7 @@ func (c *serviceClient) Ikev2InitiateSaInit(ctx context.Context, in *Ikev2Initia
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2PluginGetVersion(ctx context.Context, in *Ikev2PluginGetVersion) (*Ikev2PluginGetVersionReply, error) {
@@ -89,7 +89,7 @@ func (c *serviceClient) Ikev2ProfileAddDel(ctx context.Context, in *Ikev2Profile
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2ProfileSetAuth(ctx context.Context, in *Ikev2ProfileSetAuth) (*Ikev2ProfileSetAuthReply, error) {
@@ -98,7 +98,7 @@ func (c *serviceClient) Ikev2ProfileSetAuth(ctx context.Context, in *Ikev2Profil
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2ProfileSetID(ctx context.Context, in *Ikev2ProfileSetID) (*Ikev2ProfileSetIDReply, error) {
@@ -107,7 +107,7 @@ func (c *serviceClient) Ikev2ProfileSetID(ctx context.Context, in *Ikev2ProfileS
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2ProfileSetIpsecUDPPort(ctx context.Context, in *Ikev2ProfileSetIpsecUDPPort) (*Ikev2ProfileSetIpsecUDPPortReply, error) {
@@ -116,7 +116,7 @@ func (c *serviceClient) Ikev2ProfileSetIpsecUDPPort(ctx context.Context, in *Ike
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2ProfileSetLiveness(ctx context.Context, in *Ikev2ProfileSetLiveness) (*Ikev2ProfileSetLivenessReply, error) {
@@ -125,7 +125,7 @@ func (c *serviceClient) Ikev2ProfileSetLiveness(ctx context.Context, in *Ikev2Pr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2ProfileSetTs(ctx context.Context, in *Ikev2ProfileSetTs) (*Ikev2ProfileSetTsReply, error) {
@@ -134,7 +134,7 @@ func (c *serviceClient) Ikev2ProfileSetTs(ctx context.Context, in *Ikev2ProfileS
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2ProfileSetUDPEncap(ctx context.Context, in *Ikev2ProfileSetUDPEncap) (*Ikev2ProfileSetUDPEncapReply, error) {
@@ -143,7 +143,7 @@ func (c *serviceClient) Ikev2ProfileSetUDPEncap(ctx context.Context, in *Ikev2Pr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2SetEspTransforms(ctx context.Context, in *Ikev2SetEspTransforms) (*Ikev2SetEspTransformsReply, error) {
@@ -152,7 +152,7 @@ func (c *serviceClient) Ikev2SetEspTransforms(ctx context.Context, in *Ikev2SetE
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2SetIkeTransforms(ctx context.Context, in *Ikev2SetIkeTransforms) (*Ikev2SetIkeTransformsReply, error) {
@@ -161,7 +161,7 @@ func (c *serviceClient) Ikev2SetIkeTransforms(ctx context.Context, in *Ikev2SetI
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2SetLocalKey(ctx context.Context, in *Ikev2SetLocalKey) (*Ikev2SetLocalKeyReply, error) {
@@ -170,7 +170,7 @@ func (c *serviceClient) Ikev2SetLocalKey(ctx context.Context, in *Ikev2SetLocalK
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2SetResponder(ctx context.Context, in *Ikev2SetResponder) (*Ikev2SetResponderReply, error) {
@@ -179,7 +179,7 @@ func (c *serviceClient) Ikev2SetResponder(ctx context.Context, in *Ikev2SetRespo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2SetSaLifetime(ctx context.Context, in *Ikev2SetSaLifetime) (*Ikev2SetSaLifetimeReply, error) {
@@ -188,7 +188,7 @@ func (c *serviceClient) Ikev2SetSaLifetime(ctx context.Context, in *Ikev2SetSaLi
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ikev2SetTunnelInterface(ctx context.Context, in *Ikev2SetTunnelInterface) (*Ikev2SetTunnelInterfaceReply, error) {
@@ -197,5 +197,5 @@ func (c *serviceClient) Ikev2SetTunnelInterface(ctx context.Context, in *Ikev2Se
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/interface/interface.ba.go b/binapi/interface/interface.ba.go
index 822c325..cef8994 100644
--- a/binapi/interface/interface.ba.go
+++ b/binapi/interface/interface.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/interface.api.json
 
 // Package interfaces contains generated bindings for API file interface.api.
diff --git a/binapi/interface/interface_rest.ba.go b/binapi/interface/interface_rest.ba.go
deleted file mode 100644
index da5b899..0000000
--- a/binapi/interface/interface_rest.ba.go
+++ /dev/null
@@ -1,594 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package interfaces
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/collect_detailed_interface_stats", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(CollectDetailedInterfaceStats)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.CollectDetailedInterfaceStats(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/create_loopback", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(CreateLoopback)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.CreateLoopback(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/create_loopback_instance", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(CreateLoopbackInstance)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.CreateLoopbackInstance(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/create_subif", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(CreateSubif)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.CreateSubif(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/create_vlan_subif", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(CreateVlanSubif)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.CreateVlanSubif(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/delete_loopback", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DeleteLoopback)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DeleteLoopback(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/delete_subif", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DeleteSubif)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DeleteSubif(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/hw_interface_set_mtu", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(HwInterfaceSetMtu)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.HwInterfaceSetMtu(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/interface_name_renumber", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(InterfaceNameRenumber)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.InterfaceNameRenumber(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_add_del_address", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceAddDelAddress)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceAddDelAddress(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_add_del_mac_address", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceAddDelMacAddress)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceAddDelMacAddress(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_address_replace_begin", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceAddressReplaceBegin)
-		reply, err := rpc.SwInterfaceAddressReplaceBegin(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_address_replace_end", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceAddressReplaceEnd)
-		reply, err := rpc.SwInterfaceAddressReplaceEnd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_clear_stats", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceClearStats)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceClearStats(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_get_mac_address", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceGetMacAddress)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceGetMacAddress(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_get_table", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceGetTable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceGetTable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_flags", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetFlags)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetFlags(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_ip_directed_broadcast", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetIPDirectedBroadcast)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetIPDirectedBroadcast(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_mac_address", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetMacAddress)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetMacAddress(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_mtu", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetMtu)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetMtu(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_rx_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetRxMode)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetRxMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_rx_placement", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetRxPlacement)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetRxPlacement(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_table", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetTable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetTable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_unnumbered", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetUnnumbered)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetUnnumbered(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_tag_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceTagAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceTagAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/want_interface_events", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(WantInterfaceEvents)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.WantInterfaceEvents(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/interface/interface_rpc.ba.go b/binapi/interface/interface_rpc.ba.go
index 94d89ec..f797346 100644
--- a/binapi/interface/interface_rpc.ba.go
+++ b/binapi/interface/interface_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  interface.
+// RPCService defines RPC service interface.
 type RPCService interface {
 	CollectDetailedInterfaceStats(ctx context.Context, in *CollectDetailedInterfaceStats) (*CollectDetailedInterfaceStatsReply, error)
 	CreateLoopback(ctx context.Context, in *CreateLoopback) (*CreateLoopbackReply, error)
@@ -57,7 +57,7 @@ func (c *serviceClient) CollectDetailedInterfaceStats(ctx context.Context, in *C
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) CreateLoopback(ctx context.Context, in *CreateLoopback) (*CreateLoopbackReply, error) {
@@ -66,7 +66,7 @@ func (c *serviceClient) CreateLoopback(ctx context.Context, in *CreateLoopback)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) CreateLoopbackInstance(ctx context.Context, in *CreateLoopbackInstance) (*CreateLoopbackInstanceReply, error) {
@@ -75,7 +75,7 @@ func (c *serviceClient) CreateLoopbackInstance(ctx context.Context, in *CreateLo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) CreateSubif(ctx context.Context, in *CreateSubif) (*CreateSubifReply, error) {
@@ -84,7 +84,7 @@ func (c *serviceClient) CreateSubif(ctx context.Context, in *CreateSubif) (*Crea
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) CreateVlanSubif(ctx context.Context, in *CreateVlanSubif) (*CreateVlanSubifReply, error) {
@@ -93,7 +93,7 @@ func (c *serviceClient) CreateVlanSubif(ctx context.Context, in *CreateVlanSubif
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DeleteLoopback(ctx context.Context, in *DeleteLoopback) (*DeleteLoopbackReply, error) {
@@ -102,7 +102,7 @@ func (c *serviceClient) DeleteLoopback(ctx context.Context, in *DeleteLoopback)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DeleteSubif(ctx context.Context, in *DeleteSubif) (*DeleteSubifReply, error) {
@@ -111,7 +111,7 @@ func (c *serviceClient) DeleteSubif(ctx context.Context, in *DeleteSubif) (*Dele
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) HwInterfaceSetMtu(ctx context.Context, in *HwInterfaceSetMtu) (*HwInterfaceSetMtuReply, error) {
@@ -120,7 +120,7 @@ func (c *serviceClient) HwInterfaceSetMtu(ctx context.Context, in *HwInterfaceSe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) InterfaceNameRenumber(ctx context.Context, in *InterfaceNameRenumber) (*InterfaceNameRenumberReply, error) {
@@ -129,7 +129,7 @@ func (c *serviceClient) InterfaceNameRenumber(ctx context.Context, in *Interface
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceAddDelAddress(ctx context.Context, in *SwInterfaceAddDelAddress) (*SwInterfaceAddDelAddressReply, error) {
@@ -138,7 +138,7 @@ func (c *serviceClient) SwInterfaceAddDelAddress(ctx context.Context, in *SwInte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceAddDelMacAddress(ctx context.Context, in *SwInterfaceAddDelMacAddress) (*SwInterfaceAddDelMacAddressReply, error) {
@@ -147,7 +147,7 @@ func (c *serviceClient) SwInterfaceAddDelMacAddress(ctx context.Context, in *SwI
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceAddressReplaceBegin(ctx context.Context, in *SwInterfaceAddressReplaceBegin) (*SwInterfaceAddressReplaceBeginReply, error) {
@@ -156,7 +156,7 @@ func (c *serviceClient) SwInterfaceAddressReplaceBegin(ctx context.Context, in *
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceAddressReplaceEnd(ctx context.Context, in *SwInterfaceAddressReplaceEnd) (*SwInterfaceAddressReplaceEndReply, error) {
@@ -165,7 +165,7 @@ func (c *serviceClient) SwInterfaceAddressReplaceEnd(ctx context.Context, in *Sw
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceClearStats(ctx context.Context, in *SwInterfaceClearStats) (*SwInterfaceClearStatsReply, error) {
@@ -174,7 +174,7 @@ func (c *serviceClient) SwInterfaceClearStats(ctx context.Context, in *SwInterfa
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceDump(ctx context.Context, in *SwInterfaceDump) (RPCService_SwInterfaceDumpClient, error) {
@@ -222,7 +222,7 @@ func (c *serviceClient) SwInterfaceGetMacAddress(ctx context.Context, in *SwInte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceGetTable(ctx context.Context, in *SwInterfaceGetTable) (*SwInterfaceGetTableReply, error) {
@@ -231,7 +231,7 @@ func (c *serviceClient) SwInterfaceGetTable(ctx context.Context, in *SwInterface
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceRxPlacementDump(ctx context.Context, in *SwInterfaceRxPlacementDump) (RPCService_SwInterfaceRxPlacementDumpClient, error) {
@@ -279,7 +279,7 @@ func (c *serviceClient) SwInterfaceSetFlags(ctx context.Context, in *SwInterface
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetIPDirectedBroadcast(ctx context.Context, in *SwInterfaceSetIPDirectedBroadcast) (*SwInterfaceSetIPDirectedBroadcastReply, error) {
@@ -288,7 +288,7 @@ func (c *serviceClient) SwInterfaceSetIPDirectedBroadcast(ctx context.Context, i
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetMacAddress(ctx context.Context, in *SwInterfaceSetMacAddress) (*SwInterfaceSetMacAddressReply, error) {
@@ -297,7 +297,7 @@ func (c *serviceClient) SwInterfaceSetMacAddress(ctx context.Context, in *SwInte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetMtu(ctx context.Context, in *SwInterfaceSetMtu) (*SwInterfaceSetMtuReply, error) {
@@ -306,7 +306,7 @@ func (c *serviceClient) SwInterfaceSetMtu(ctx context.Context, in *SwInterfaceSe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetRxMode(ctx context.Context, in *SwInterfaceSetRxMode) (*SwInterfaceSetRxModeReply, error) {
@@ -315,7 +315,7 @@ func (c *serviceClient) SwInterfaceSetRxMode(ctx context.Context, in *SwInterfac
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetRxPlacement(ctx context.Context, in *SwInterfaceSetRxPlacement) (*SwInterfaceSetRxPlacementReply, error) {
@@ -324,7 +324,7 @@ func (c *serviceClient) SwInterfaceSetRxPlacement(ctx context.Context, in *SwInt
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetTable(ctx context.Context, in *SwInterfaceSetTable) (*SwInterfaceSetTableReply, error) {
@@ -333,7 +333,7 @@ func (c *serviceClient) SwInterfaceSetTable(ctx context.Context, in *SwInterface
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetUnnumbered(ctx context.Context, in *SwInterfaceSetUnnumbered) (*SwInterfaceSetUnnumberedReply, error) {
@@ -342,7 +342,7 @@ func (c *serviceClient) SwInterfaceSetUnnumbered(ctx context.Context, in *SwInte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceTagAddDel(ctx context.Context, in *SwInterfaceTagAddDel) (*SwInterfaceTagAddDelReply, error) {
@@ -351,7 +351,7 @@ func (c *serviceClient) SwInterfaceTagAddDel(ctx context.Context, in *SwInterfac
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) WantInterfaceEvents(ctx context.Context, in *WantInterfaceEvents) (*WantInterfaceEventsReply, error) {
@@ -360,5 +360,5 @@ func (c *serviceClient) WantInterfaceEvents(ctx context.Context, in *WantInterfa
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/interface_types/interface_types.ba.go b/binapi/interface_types/interface_types.ba.go
index f7f8c2e..d2a848a 100644
--- a/binapi/interface_types/interface_types.ba.go
+++ b/binapi/interface_types/interface_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/interface_types.api.json
 
 // Package interface_types contains generated bindings for API file interface_types.api.
diff --git a/binapi/ioam_cache/ioam_cache.ba.go b/binapi/ioam_cache/ioam_cache.ba.go
index 2f9f0ef..1bae621 100644
--- a/binapi/ioam_cache/ioam_cache.ba.go
+++ b/binapi/ioam_cache/ioam_cache.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/ioam_cache.api.json
 
 // Package ioam_cache contains generated bindings for API file ioam_cache.api.
diff --git a/binapi/ioam_cache/ioam_cache_rest.ba.go b/binapi/ioam_cache/ioam_cache_rest.ba.go
deleted file mode 100644
index 4090307..0000000
--- a/binapi/ioam_cache/ioam_cache_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ioam_cache
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ioam_cache_ip6_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IoamCacheIP6EnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IoamCacheIP6EnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ioam_cache/ioam_cache_rpc.ba.go b/binapi/ioam_cache/ioam_cache_rpc.ba.go
index 0705965..9847365 100644
--- a/binapi/ioam_cache/ioam_cache_rpc.ba.go
+++ b/binapi/ioam_cache/ioam_cache_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  ioam_cache.
+// RPCService defines RPC service ioam_cache.
 type RPCService interface {
 	IoamCacheIP6EnableDisable(ctx context.Context, in *IoamCacheIP6EnableDisable) (*IoamCacheIP6EnableDisableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) IoamCacheIP6EnableDisable(ctx context.Context, in *IoamC
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ioam_export/ioam_export.ba.go b/binapi/ioam_export/ioam_export.ba.go
index 47dd4e2..b272777 100644
--- a/binapi/ioam_export/ioam_export.ba.go
+++ b/binapi/ioam_export/ioam_export.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/ioam_export.api.json
 
 // Package ioam_export contains generated bindings for API file ioam_export.api.
diff --git a/binapi/ioam_export/ioam_export_rest.ba.go b/binapi/ioam_export/ioam_export_rest.ba.go
deleted file mode 100644
index 06ee0bc..0000000
--- a/binapi/ioam_export/ioam_export_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ioam_export
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ioam_export_ip6_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IoamExportIP6EnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IoamExportIP6EnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ioam_export/ioam_export_rpc.ba.go b/binapi/ioam_export/ioam_export_rpc.ba.go
index 9cf5396..0e0da2e 100644
--- a/binapi/ioam_export/ioam_export_rpc.ba.go
+++ b/binapi/ioam_export/ioam_export_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  ioam_export.
+// RPCService defines RPC service ioam_export.
 type RPCService interface {
 	IoamExportIP6EnableDisable(ctx context.Context, in *IoamExportIP6EnableDisable) (*IoamExportIP6EnableDisableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) IoamExportIP6EnableDisable(ctx context.Context, in *Ioam
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe.ba.go b/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe.ba.go
index 7d1bb35..226071f 100644
--- a/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe.ba.go
+++ b/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/ioam_vxlan_gpe.api.json
 
 // Package ioam_vxlan_gpe contains generated bindings for API file ioam_vxlan_gpe.api.
diff --git a/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe_rest.ba.go b/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe_rest.ba.go
deleted file mode 100644
index bc34d36..0000000
--- a/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe_rest.ba.go
+++ /dev/null
@@ -1,152 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ioam_vxlan_gpe
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/vxlan_gpe_ioam_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanGpeIoamDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanGpeIoamDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vxlan_gpe_ioam_enable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanGpeIoamEnable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanGpeIoamEnable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vxlan_gpe_ioam_transit_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanGpeIoamTransitDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanGpeIoamTransitDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vxlan_gpe_ioam_transit_enable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanGpeIoamTransitEnable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanGpeIoamTransitEnable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vxlan_gpe_ioam_vni_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanGpeIoamVniDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanGpeIoamVniDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vxlan_gpe_ioam_vni_enable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanGpeIoamVniEnable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanGpeIoamVniEnable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe_rpc.ba.go b/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe_rpc.ba.go
index eca5d4c..19bdbb2 100644
--- a/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe_rpc.ba.go
+++ b/binapi/ioam_vxlan_gpe/ioam_vxlan_gpe_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  ioam_vxlan_gpe.
+// RPCService defines RPC service ioam_vxlan_gpe.
 type RPCService interface {
 	VxlanGpeIoamDisable(ctx context.Context, in *VxlanGpeIoamDisable) (*VxlanGpeIoamDisableReply, error)
 	VxlanGpeIoamEnable(ctx context.Context, in *VxlanGpeIoamEnable) (*VxlanGpeIoamEnableReply, error)
@@ -32,7 +32,7 @@ func (c *serviceClient) VxlanGpeIoamDisable(ctx context.Context, in *VxlanGpeIoa
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanGpeIoamEnable(ctx context.Context, in *VxlanGpeIoamEnable) (*VxlanGpeIoamEnableReply, error) {
@@ -41,7 +41,7 @@ func (c *serviceClient) VxlanGpeIoamEnable(ctx context.Context, in *VxlanGpeIoam
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanGpeIoamTransitDisable(ctx context.Context, in *VxlanGpeIoamTransitDisable) (*VxlanGpeIoamTransitDisableReply, error) {
@@ -50,7 +50,7 @@ func (c *serviceClient) VxlanGpeIoamTransitDisable(ctx context.Context, in *Vxla
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanGpeIoamTransitEnable(ctx context.Context, in *VxlanGpeIoamTransitEnable) (*VxlanGpeIoamTransitEnableReply, error) {
@@ -59,7 +59,7 @@ func (c *serviceClient) VxlanGpeIoamTransitEnable(ctx context.Context, in *Vxlan
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanGpeIoamVniDisable(ctx context.Context, in *VxlanGpeIoamVniDisable) (*VxlanGpeIoamVniDisableReply, error) {
@@ -68,7 +68,7 @@ func (c *serviceClient) VxlanGpeIoamVniDisable(ctx context.Context, in *VxlanGpe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanGpeIoamVniEnable(ctx context.Context, in *VxlanGpeIoamVniEnable) (*VxlanGpeIoamVniEnableReply, error) {
@@ -77,5 +77,5 @@ func (c *serviceClient) VxlanGpeIoamVniEnable(ctx context.Context, in *VxlanGpeI
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ip/ip.ba.go b/binapi/ip/ip.ba.go
index b036e9c..ce8278c 100644
--- a/binapi/ip/ip.ba.go
+++ b/binapi/ip/ip.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/ip.api.json
 
 // Package ip contains generated bindings for API file ip.api.
diff --git a/binapi/ip/ip_rest.ba.go b/binapi/ip/ip_rest.ba.go
deleted file mode 100644
index 245ffed..0000000
--- a/binapi/ip/ip_rest.ba.go
+++ /dev/null
@@ -1,474 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ip
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ioam_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IoamDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IoamDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ioam_enable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IoamEnable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IoamEnable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_container_proxy_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPContainerProxyAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPContainerProxyAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_mroute_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPMrouteAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPMrouteAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_punt_police", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPPuntPolice)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPPuntPolice(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_punt_redirect", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPPuntRedirect)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPPuntRedirect(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_reassembly_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPReassemblyEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPReassemblyEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_reassembly_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPReassemblyGet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPReassemblyGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_reassembly_set", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPReassemblySet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPReassemblySet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_route_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPRouteAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPRouteAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_route_lookup", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPRouteLookup)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPRouteLookup(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_source_and_port_range_check_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPSourceAndPortRangeCheckAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPSourceAndPortRangeCheckAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_source_and_port_range_check_interface_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPSourceAndPortRangeCheckInterfaceAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPSourceAndPortRangeCheckInterfaceAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_table_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPTableAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPTableAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_table_flush", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPTableFlush)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPTableFlush(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_table_replace_begin", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPTableReplaceBegin)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPTableReplaceBegin(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_table_replace_end", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPTableReplaceEnd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPTableReplaceEnd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/set_ip_flow_hash", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SetIPFlowHash)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SetIPFlowHash(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_ip6_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceIP6EnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceIP6EnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_ip6_set_link_local_address", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceIP6SetLinkLocalAddress)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceIP6SetLinkLocalAddress(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ip/ip_rpc.ba.go b/binapi/ip/ip_rpc.ba.go
index a27c082..32ea1b5 100644
--- a/binapi/ip/ip_rpc.ba.go
+++ b/binapi/ip/ip_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  ip.
+// RPCService defines RPC service ip.
 type RPCService interface {
 	IoamDisable(ctx context.Context, in *IoamDisable) (*IoamDisableReply, error)
 	IoamEnable(ctx context.Context, in *IoamEnable) (*IoamEnableReply, error)
@@ -59,7 +59,7 @@ func (c *serviceClient) IoamDisable(ctx context.Context, in *IoamDisable) (*Ioam
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IoamEnable(ctx context.Context, in *IoamEnable) (*IoamEnableReply, error) {
@@ -68,7 +68,7 @@ func (c *serviceClient) IoamEnable(ctx context.Context, in *IoamEnable) (*IoamEn
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPAddressDump(ctx context.Context, in *IPAddressDump) (RPCService_IPAddressDumpClient, error) {
@@ -116,7 +116,7 @@ func (c *serviceClient) IPContainerProxyAddDel(ctx context.Context, in *IPContai
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPContainerProxyDump(ctx context.Context, in *IPContainerProxyDump) (RPCService_IPContainerProxyDumpClient, error) {
@@ -203,7 +203,7 @@ func (c *serviceClient) IPMrouteAddDel(ctx context.Context, in *IPMrouteAddDel)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPMrouteDump(ctx context.Context, in *IPMrouteDump) (RPCService_IPMrouteDumpClient, error) {
@@ -290,7 +290,7 @@ func (c *serviceClient) IPPuntPolice(ctx context.Context, in *IPPuntPolice) (*IP
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPPuntRedirect(ctx context.Context, in *IPPuntRedirect) (*IPPuntRedirectReply, error) {
@@ -299,7 +299,7 @@ func (c *serviceClient) IPPuntRedirect(ctx context.Context, in *IPPuntRedirect)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPPuntRedirectDump(ctx context.Context, in *IPPuntRedirectDump) (RPCService_IPPuntRedirectDumpClient, error) {
@@ -347,7 +347,7 @@ func (c *serviceClient) IPReassemblyEnableDisable(ctx context.Context, in *IPRea
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPReassemblyGet(ctx context.Context, in *IPReassemblyGet) (*IPReassemblyGetReply, error) {
@@ -356,7 +356,7 @@ func (c *serviceClient) IPReassemblyGet(ctx context.Context, in *IPReassemblyGet
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPReassemblySet(ctx context.Context, in *IPReassemblySet) (*IPReassemblySetReply, error) {
@@ -365,7 +365,7 @@ func (c *serviceClient) IPReassemblySet(ctx context.Context, in *IPReassemblySet
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPRouteAddDel(ctx context.Context, in *IPRouteAddDel) (*IPRouteAddDelReply, error) {
@@ -374,7 +374,7 @@ func (c *serviceClient) IPRouteAddDel(ctx context.Context, in *IPRouteAddDel) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPRouteDump(ctx context.Context, in *IPRouteDump) (RPCService_IPRouteDumpClient, error) {
@@ -422,7 +422,7 @@ func (c *serviceClient) IPRouteLookup(ctx context.Context, in *IPRouteLookup) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPSourceAndPortRangeCheckAddDel(ctx context.Context, in *IPSourceAndPortRangeCheckAddDel) (*IPSourceAndPortRangeCheckAddDelReply, error) {
@@ -431,7 +431,7 @@ func (c *serviceClient) IPSourceAndPortRangeCheckAddDel(ctx context.Context, in
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPSourceAndPortRangeCheckInterfaceAddDel(ctx context.Context, in *IPSourceAndPortRangeCheckInterfaceAddDel) (*IPSourceAndPortRangeCheckInterfaceAddDelReply, error) {
@@ -440,7 +440,7 @@ func (c *serviceClient) IPSourceAndPortRangeCheckInterfaceAddDel(ctx context.Con
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPTableAddDel(ctx context.Context, in *IPTableAddDel) (*IPTableAddDelReply, error) {
@@ -449,7 +449,7 @@ func (c *serviceClient) IPTableAddDel(ctx context.Context, in *IPTableAddDel) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPTableDump(ctx context.Context, in *IPTableDump) (RPCService_IPTableDumpClient, error) {
@@ -497,7 +497,7 @@ func (c *serviceClient) IPTableFlush(ctx context.Context, in *IPTableFlush) (*IP
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPTableReplaceBegin(ctx context.Context, in *IPTableReplaceBegin) (*IPTableReplaceBeginReply, error) {
@@ -506,7 +506,7 @@ func (c *serviceClient) IPTableReplaceBegin(ctx context.Context, in *IPTableRepl
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPTableReplaceEnd(ctx context.Context, in *IPTableReplaceEnd) (*IPTableReplaceEndReply, error) {
@@ -515,7 +515,7 @@ func (c *serviceClient) IPTableReplaceEnd(ctx context.Context, in *IPTableReplac
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPUnnumberedDump(ctx context.Context, in *IPUnnumberedDump) (RPCService_IPUnnumberedDumpClient, error) {
@@ -602,7 +602,7 @@ func (c *serviceClient) SetIPFlowHash(ctx context.Context, in *SetIPFlowHash) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceIP6EnableDisable(ctx context.Context, in *SwInterfaceIP6EnableDisable) (*SwInterfaceIP6EnableDisableReply, error) {
@@ -611,7 +611,7 @@ func (c *serviceClient) SwInterfaceIP6EnableDisable(ctx context.Context, in *SwI
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceIP6SetLinkLocalAddress(ctx context.Context, in *SwInterfaceIP6SetLinkLocalAddress) (*SwInterfaceIP6SetLinkLocalAddressReply, error) {
@@ -620,5 +620,5 @@ func (c *serviceClient) SwInterfaceIP6SetLinkLocalAddress(ctx context.Context, i
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ip6_nd/ip6_nd.ba.go b/binapi/ip6_nd/ip6_nd.ba.go
index a5f308e..9149861 100644
--- a/binapi/ip6_nd/ip6_nd.ba.go
+++ b/binapi/ip6_nd/ip6_nd.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/ip6_nd.api.json
 
 // Package ip6_nd contains generated bindings for API file ip6_nd.api.
diff --git a/binapi/ip6_nd/ip6_nd_rest.ba.go b/binapi/ip6_nd/ip6_nd_rest.ba.go
deleted file mode 100644
index 2bd060d..0000000
--- a/binapi/ip6_nd/ip6_nd_rest.ba.go
+++ /dev/null
@@ -1,129 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ip6_nd
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ip6nd_proxy_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IP6ndProxyAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IP6ndProxyAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip6nd_send_router_solicitation", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IP6ndSendRouterSolicitation)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IP6ndSendRouterSolicitation(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_ip6nd_ra_config", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceIP6ndRaConfig)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceIP6ndRaConfig(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_ip6nd_ra_prefix", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceIP6ndRaPrefix)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceIP6ndRaPrefix(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/want_ip6_ra_events", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(WantIP6RaEvents)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.WantIP6RaEvents(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ip6_nd/ip6_nd_rpc.ba.go b/binapi/ip6_nd/ip6_nd_rpc.ba.go
index 49e75cc..24e345f 100644
--- a/binapi/ip6_nd/ip6_nd_rpc.ba.go
+++ b/binapi/ip6_nd/ip6_nd_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  ip6_nd.
+// RPCService defines RPC service ip6_nd.
 type RPCService interface {
 	IP6ndProxyAddDel(ctx context.Context, in *IP6ndProxyAddDel) (*IP6ndProxyAddDelReply, error)
 	IP6ndProxyDump(ctx context.Context, in *IP6ndProxyDump) (RPCService_IP6ndProxyDumpClient, error)
@@ -35,7 +35,7 @@ func (c *serviceClient) IP6ndProxyAddDel(ctx context.Context, in *IP6ndProxyAddD
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IP6ndProxyDump(ctx context.Context, in *IP6ndProxyDump) (RPCService_IP6ndProxyDumpClient, error) {
@@ -83,7 +83,7 @@ func (c *serviceClient) IP6ndSendRouterSolicitation(ctx context.Context, in *IP6
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceIP6ndRaConfig(ctx context.Context, in *SwInterfaceIP6ndRaConfig) (*SwInterfaceIP6ndRaConfigReply, error) {
@@ -92,7 +92,7 @@ func (c *serviceClient) SwInterfaceIP6ndRaConfig(ctx context.Context, in *SwInte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceIP6ndRaPrefix(ctx context.Context, in *SwInterfaceIP6ndRaPrefix) (*SwInterfaceIP6ndRaPrefixReply, error) {
@@ -101,7 +101,7 @@ func (c *serviceClient) SwInterfaceIP6ndRaPrefix(ctx context.Context, in *SwInte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) WantIP6RaEvents(ctx context.Context, in *WantIP6RaEvents) (*WantIP6RaEventsReply, error) {
@@ -110,5 +110,5 @@ func (c *serviceClient) WantIP6RaEvents(ctx context.Context, in *WantIP6RaEvents
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ip_neighbor/ip_neighbor.ba.go b/binapi/ip_neighbor/ip_neighbor.ba.go
index 3215f5d..ec5b5ed 100644
--- a/binapi/ip_neighbor/ip_neighbor.ba.go
+++ b/binapi/ip_neighbor/ip_neighbor.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/ip_neighbor.api.json
 
 // Package ip_neighbor contains generated bindings for API file ip_neighbor.api.
diff --git a/binapi/ip_neighbor/ip_neighbor_rest.ba.go b/binapi/ip_neighbor/ip_neighbor_rest.ba.go
deleted file mode 100644
index 7db4694..0000000
--- a/binapi/ip_neighbor/ip_neighbor_rest.ba.go
+++ /dev/null
@@ -1,134 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ip_neighbor
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ip_neighbor_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPNeighborAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPNeighborAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_neighbor_config", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPNeighborConfig)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPNeighborConfig(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_neighbor_flush", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPNeighborFlush)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IPNeighborFlush(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_neighbor_replace_begin", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPNeighborReplaceBegin)
-		reply, err := rpc.IPNeighborReplaceBegin(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ip_neighbor_replace_end", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IPNeighborReplaceEnd)
-		reply, err := rpc.IPNeighborReplaceEnd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/want_ip_neighbor_events", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(WantIPNeighborEvents)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.WantIPNeighborEvents(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ip_neighbor/ip_neighbor_rpc.ba.go b/binapi/ip_neighbor/ip_neighbor_rpc.ba.go
index 1d34965..94b2060 100644
--- a/binapi/ip_neighbor/ip_neighbor_rpc.ba.go
+++ b/binapi/ip_neighbor/ip_neighbor_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  ip_neighbor.
+// RPCService defines RPC service ip_neighbor.
 type RPCService interface {
 	IPNeighborAddDel(ctx context.Context, in *IPNeighborAddDel) (*IPNeighborAddDelReply, error)
 	IPNeighborConfig(ctx context.Context, in *IPNeighborConfig) (*IPNeighborConfigReply, error)
@@ -36,7 +36,7 @@ func (c *serviceClient) IPNeighborAddDel(ctx context.Context, in *IPNeighborAddD
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPNeighborConfig(ctx context.Context, in *IPNeighborConfig) (*IPNeighborConfigReply, error) {
@@ -45,7 +45,7 @@ func (c *serviceClient) IPNeighborConfig(ctx context.Context, in *IPNeighborConf
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPNeighborDump(ctx context.Context, in *IPNeighborDump) (RPCService_IPNeighborDumpClient, error) {
@@ -93,7 +93,7 @@ func (c *serviceClient) IPNeighborFlush(ctx context.Context, in *IPNeighborFlush
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPNeighborReplaceBegin(ctx context.Context, in *IPNeighborReplaceBegin) (*IPNeighborReplaceBeginReply, error) {
@@ -102,7 +102,7 @@ func (c *serviceClient) IPNeighborReplaceBegin(ctx context.Context, in *IPNeighb
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IPNeighborReplaceEnd(ctx context.Context, in *IPNeighborReplaceEnd) (*IPNeighborReplaceEndReply, error) {
@@ -111,7 +111,7 @@ func (c *serviceClient) IPNeighborReplaceEnd(ctx context.Context, in *IPNeighbor
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) WantIPNeighborEvents(ctx context.Context, in *WantIPNeighborEvents) (*WantIPNeighborEventsReply, error) {
@@ -120,5 +120,5 @@ func (c *serviceClient) WantIPNeighborEvents(ctx context.Context, in *WantIPNeig
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ip_types/ip_types.ba.go b/binapi/ip_types/ip_types.ba.go
index 90363f8..3350fab 100644
--- a/binapi/ip_types/ip_types.ba.go
+++ b/binapi/ip_types/ip_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/ip_types.api.json
 
 // Package ip_types contains generated bindings for API file ip_types.api.
diff --git a/binapi/ipfix_export/ipfix_export.ba.go b/binapi/ipfix_export/ipfix_export.ba.go
index e173058..e74441c 100644
--- a/binapi/ipfix_export/ipfix_export.ba.go
+++ b/binapi/ipfix_export/ipfix_export.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/ipfix_export.api.json
 
 // Package ipfix_export contains generated bindings for API file ipfix_export.api.
diff --git a/binapi/ipfix_export/ipfix_export_rest.ba.go b/binapi/ipfix_export/ipfix_export_rest.ba.go
deleted file mode 100644
index 65407bf..0000000
--- a/binapi/ipfix_export/ipfix_export_rest.ba.go
+++ /dev/null
@@ -1,97 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ipfix_export
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ipfix_classify_table_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpfixClassifyTableAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpfixClassifyTableAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipfix_flush", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpfixFlush)
-		reply, err := rpc.IpfixFlush(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/set_ipfix_classify_stream", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SetIpfixClassifyStream)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SetIpfixClassifyStream(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/set_ipfix_exporter", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SetIpfixExporter)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SetIpfixExporter(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ipfix_export/ipfix_export_rpc.ba.go b/binapi/ipfix_export/ipfix_export_rpc.ba.go
index e65fa47..d577393 100644
--- a/binapi/ipfix_export/ipfix_export_rpc.ba.go
+++ b/binapi/ipfix_export/ipfix_export_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  ipfix_export.
+// RPCService defines RPC service ipfix_export.
 type RPCService interface {
 	IpfixClassifyStreamDump(ctx context.Context, in *IpfixClassifyStreamDump) (RPCService_IpfixClassifyStreamDumpClient, error)
 	IpfixClassifyTableAddDel(ctx context.Context, in *IpfixClassifyTableAddDel) (*IpfixClassifyTableAddDelReply, error)
@@ -75,7 +75,7 @@ func (c *serviceClient) IpfixClassifyTableAddDel(ctx context.Context, in *IpfixC
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpfixClassifyTableDump(ctx context.Context, in *IpfixClassifyTableDump) (RPCService_IpfixClassifyTableDumpClient, error) {
@@ -162,7 +162,7 @@ func (c *serviceClient) IpfixFlush(ctx context.Context, in *IpfixFlush) (*IpfixF
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SetIpfixClassifyStream(ctx context.Context, in *SetIpfixClassifyStream) (*SetIpfixClassifyStreamReply, error) {
@@ -171,7 +171,7 @@ func (c *serviceClient) SetIpfixClassifyStream(ctx context.Context, in *SetIpfix
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SetIpfixExporter(ctx context.Context, in *SetIpfixExporter) (*SetIpfixExporterReply, error) {
@@ -180,5 +180,5 @@ func (c *serviceClient) SetIpfixExporter(ctx context.Context, in *SetIpfixExport
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ipip/ipip.ba.go b/binapi/ipip/ipip.ba.go
index 05821cb..48f9df2 100644
--- a/binapi/ipip/ipip.ba.go
+++ b/binapi/ipip/ipip.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/ipip.api.json
 
 // Package ipip contains generated bindings for API file ipip.api.
diff --git a/binapi/ipip/ipip_rest.ba.go b/binapi/ipip/ipip_rest.ba.go
deleted file mode 100644
index 63fe220..0000000
--- a/binapi/ipip/ipip_rest.ba.go
+++ /dev/null
@@ -1,106 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ipip
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ipip_6rd_add_tunnel", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ipip6rdAddTunnel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ipip6rdAddTunnel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipip_6rd_del_tunnel", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Ipip6rdDelTunnel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Ipip6rdDelTunnel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipip_add_tunnel", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpipAddTunnel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpipAddTunnel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipip_del_tunnel", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpipDelTunnel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpipDelTunnel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ipip/ipip_rpc.ba.go b/binapi/ipip/ipip_rpc.ba.go
index a3e4cc7..37b8821 100644
--- a/binapi/ipip/ipip_rpc.ba.go
+++ b/binapi/ipip/ipip_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  ipip.
+// RPCService defines RPC service ipip.
 type RPCService interface {
 	Ipip6rdAddTunnel(ctx context.Context, in *Ipip6rdAddTunnel) (*Ipip6rdAddTunnelReply, error)
 	Ipip6rdDelTunnel(ctx context.Context, in *Ipip6rdDelTunnel) (*Ipip6rdDelTunnelReply, error)
@@ -34,7 +34,7 @@ func (c *serviceClient) Ipip6rdAddTunnel(ctx context.Context, in *Ipip6rdAddTunn
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Ipip6rdDelTunnel(ctx context.Context, in *Ipip6rdDelTunnel) (*Ipip6rdDelTunnelReply, error) {
@@ -43,7 +43,7 @@ func (c *serviceClient) Ipip6rdDelTunnel(ctx context.Context, in *Ipip6rdDelTunn
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpipAddTunnel(ctx context.Context, in *IpipAddTunnel) (*IpipAddTunnelReply, error) {
@@ -52,7 +52,7 @@ func (c *serviceClient) IpipAddTunnel(ctx context.Context, in *IpipAddTunnel) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpipDelTunnel(ctx context.Context, in *IpipDelTunnel) (*IpipDelTunnelReply, error) {
@@ -61,7 +61,7 @@ func (c *serviceClient) IpipDelTunnel(ctx context.Context, in *IpipDelTunnel) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpipTunnelDump(ctx context.Context, in *IpipTunnelDump) (RPCService_IpipTunnelDumpClient, error) {
diff --git a/binapi/ipsec/ipsec.ba.go b/binapi/ipsec/ipsec.ba.go
index b777353..0ed6714 100644
--- a/binapi/ipsec/ipsec.ba.go
+++ b/binapi/ipsec/ipsec.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/ipsec.api.json
 
 // Package ipsec contains generated bindings for API file ipsec.api.
diff --git a/binapi/ipsec/ipsec_rest.ba.go b/binapi/ipsec/ipsec_rest.ba.go
deleted file mode 100644
index 166ebcd..0000000
--- a/binapi/ipsec/ipsec_rest.ba.go
+++ /dev/null
@@ -1,221 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package ipsec
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ipsec_interface_add_del_spd", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpsecInterfaceAddDelSpd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpsecInterfaceAddDelSpd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipsec_sad_entry_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpsecSadEntryAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpsecSadEntryAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipsec_select_backend", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpsecSelectBackend)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpsecSelectBackend(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipsec_spd_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpsecSpdAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpsecSpdAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipsec_spd_entry_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpsecSpdEntryAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpsecSpdEntryAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipsec_tunnel_if_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpsecTunnelIfAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpsecTunnelIfAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipsec_tunnel_if_set_sa", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpsecTunnelIfSetSa)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpsecTunnelIfSetSa(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipsec_tunnel_protect_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpsecTunnelProtectDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpsecTunnelProtectDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/ipsec_tunnel_protect_update", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IpsecTunnelProtectUpdate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IpsecTunnelProtectUpdate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/ipsec/ipsec_rpc.ba.go b/binapi/ipsec/ipsec_rpc.ba.go
index 953c1a0..1e6b81d 100644
--- a/binapi/ipsec/ipsec_rpc.ba.go
+++ b/binapi/ipsec/ipsec_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  ipsec.
+// RPCService defines RPC service ipsec.
 type RPCService interface {
 	IpsecBackendDump(ctx context.Context, in *IpsecBackendDump) (RPCService_IpsecBackendDumpClient, error)
 	IpsecInterfaceAddDelSpd(ctx context.Context, in *IpsecInterfaceAddDelSpd) (*IpsecInterfaceAddDelSpdReply, error)
@@ -83,7 +83,7 @@ func (c *serviceClient) IpsecInterfaceAddDelSpd(ctx context.Context, in *IpsecIn
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpsecSaDump(ctx context.Context, in *IpsecSaDump) (RPCService_IpsecSaDumpClient, error) {
@@ -131,7 +131,7 @@ func (c *serviceClient) IpsecSadEntryAddDel(ctx context.Context, in *IpsecSadEnt
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpsecSelectBackend(ctx context.Context, in *IpsecSelectBackend) (*IpsecSelectBackendReply, error) {
@@ -140,7 +140,7 @@ func (c *serviceClient) IpsecSelectBackend(ctx context.Context, in *IpsecSelectB
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpsecSpdAddDel(ctx context.Context, in *IpsecSpdAddDel) (*IpsecSpdAddDelReply, error) {
@@ -149,7 +149,7 @@ func (c *serviceClient) IpsecSpdAddDel(ctx context.Context, in *IpsecSpdAddDel)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpsecSpdDump(ctx context.Context, in *IpsecSpdDump) (RPCService_IpsecSpdDumpClient, error) {
@@ -197,7 +197,7 @@ func (c *serviceClient) IpsecSpdEntryAddDel(ctx context.Context, in *IpsecSpdEnt
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpsecSpdInterfaceDump(ctx context.Context, in *IpsecSpdInterfaceDump) (RPCService_IpsecSpdInterfaceDumpClient, error) {
@@ -284,7 +284,7 @@ func (c *serviceClient) IpsecTunnelIfAddDel(ctx context.Context, in *IpsecTunnel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpsecTunnelIfSetSa(ctx context.Context, in *IpsecTunnelIfSetSa) (*IpsecTunnelIfSetSaReply, error) {
@@ -293,7 +293,7 @@ func (c *serviceClient) IpsecTunnelIfSetSa(ctx context.Context, in *IpsecTunnelI
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpsecTunnelProtectDel(ctx context.Context, in *IpsecTunnelProtectDel) (*IpsecTunnelProtectDelReply, error) {
@@ -302,7 +302,7 @@ func (c *serviceClient) IpsecTunnelProtectDel(ctx context.Context, in *IpsecTunn
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) IpsecTunnelProtectDump(ctx context.Context, in *IpsecTunnelProtectDump) (RPCService_IpsecTunnelProtectDumpClient, error) {
@@ -350,5 +350,5 @@ func (c *serviceClient) IpsecTunnelProtectUpdate(ctx context.Context, in *IpsecT
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/ipsec_types/ipsec_types.ba.go b/binapi/ipsec_types/ipsec_types.ba.go
index 4e7e29e..aa83d09 100644
--- a/binapi/ipsec_types/ipsec_types.ba.go
+++ b/binapi/ipsec_types/ipsec_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/ipsec_types.api.json
 
 // Package ipsec_types contains generated bindings for API file ipsec_types.api.
diff --git a/binapi/l2/l2.ba.go b/binapi/l2/l2.ba.go
index d924837..745157e 100644
--- a/binapi/l2/l2.ba.go
+++ b/binapi/l2/l2.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/l2.api.json
 
 // Package l2 contains generated bindings for API file l2.api.
diff --git a/binapi/l2/l2_rest.ba.go b/binapi/l2/l2_rest.ba.go
deleted file mode 100644
index f12ab06..0000000
--- a/binapi/l2/l2_rest.ba.go
+++ /dev/null
@@ -1,502 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package l2
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/bd_ip_mac_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BdIPMacAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BdIPMacAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bd_ip_mac_flush", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BdIPMacFlush)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BdIPMacFlush(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bridge_domain_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BridgeDomainAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BridgeDomainAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bridge_domain_set_mac_age", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BridgeDomainSetMacAge)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BridgeDomainSetMacAge(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bridge_flags", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BridgeFlags)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BridgeFlags(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bvi_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BviCreate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BviCreate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/bvi_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(BviDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.BviDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2_fib_clear_table", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2FibClearTable)
-		reply, err := rpc.L2FibClearTable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2_flags", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2Flags)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2Flags(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2_interface_efp_filter", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2InterfaceEfpFilter)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2InterfaceEfpFilter(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2_interface_pbb_tag_rewrite", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2InterfacePbbTagRewrite)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2InterfacePbbTagRewrite(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2_interface_vlan_tag_rewrite", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2InterfaceVlanTagRewrite)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2InterfaceVlanTagRewrite(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2_patch_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2PatchAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2PatchAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2fib_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2fibAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2fibAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2fib_flush_all", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2fibFlushAll)
-		reply, err := rpc.L2fibFlushAll(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2fib_flush_bd", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2fibFlushBd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2fibFlushBd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2fib_flush_int", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2fibFlushInt)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2fibFlushInt(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_l2_bridge", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetL2Bridge)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetL2Bridge(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_l2_xconnect", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetL2Xconnect)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetL2Xconnect(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_vpath", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetVpath)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetVpath(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/want_l2_arp_term_events", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(WantL2ArpTermEvents)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.WantL2ArpTermEvents(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/want_l2_macs_events", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(WantL2MacsEvents)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.WantL2MacsEvents(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/l2/l2_rpc.ba.go b/binapi/l2/l2_rpc.ba.go
index 9e4489a..bf097ee 100644
--- a/binapi/l2/l2_rpc.ba.go
+++ b/binapi/l2/l2_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  l2.
+// RPCService defines RPC service l2.
 type RPCService interface {
 	BdIPMacAddDel(ctx context.Context, in *BdIPMacAddDel) (*BdIPMacAddDelReply, error)
 	BdIPMacDump(ctx context.Context, in *BdIPMacDump) (RPCService_BdIPMacDumpClient, error)
@@ -55,7 +55,7 @@ func (c *serviceClient) BdIPMacAddDel(ctx context.Context, in *BdIPMacAddDel) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BdIPMacDump(ctx context.Context, in *BdIPMacDump) (RPCService_BdIPMacDumpClient, error) {
@@ -103,7 +103,7 @@ func (c *serviceClient) BdIPMacFlush(ctx context.Context, in *BdIPMacFlush) (*Bd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BridgeDomainAddDel(ctx context.Context, in *BridgeDomainAddDel) (*BridgeDomainAddDelReply, error) {
@@ -112,7 +112,7 @@ func (c *serviceClient) BridgeDomainAddDel(ctx context.Context, in *BridgeDomain
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BridgeDomainDump(ctx context.Context, in *BridgeDomainDump) (RPCService_BridgeDomainDumpClient, error) {
@@ -160,7 +160,7 @@ func (c *serviceClient) BridgeDomainSetMacAge(ctx context.Context, in *BridgeDom
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BridgeFlags(ctx context.Context, in *BridgeFlags) (*BridgeFlagsReply, error) {
@@ -169,7 +169,7 @@ func (c *serviceClient) BridgeFlags(ctx context.Context, in *BridgeFlags) (*Brid
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BviCreate(ctx context.Context, in *BviCreate) (*BviCreateReply, error) {
@@ -178,7 +178,7 @@ func (c *serviceClient) BviCreate(ctx context.Context, in *BviCreate) (*BviCreat
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) BviDelete(ctx context.Context, in *BviDelete) (*BviDeleteReply, error) {
@@ -187,7 +187,7 @@ func (c *serviceClient) BviDelete(ctx context.Context, in *BviDelete) (*BviDelet
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2FibClearTable(ctx context.Context, in *L2FibClearTable) (*L2FibClearTableReply, error) {
@@ -196,7 +196,7 @@ func (c *serviceClient) L2FibClearTable(ctx context.Context, in *L2FibClearTable
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2FibTableDump(ctx context.Context, in *L2FibTableDump) (RPCService_L2FibTableDumpClient, error) {
@@ -244,7 +244,7 @@ func (c *serviceClient) L2Flags(ctx context.Context, in *L2Flags) (*L2FlagsReply
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2InterfaceEfpFilter(ctx context.Context, in *L2InterfaceEfpFilter) (*L2InterfaceEfpFilterReply, error) {
@@ -253,7 +253,7 @@ func (c *serviceClient) L2InterfaceEfpFilter(ctx context.Context, in *L2Interfac
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2InterfacePbbTagRewrite(ctx context.Context, in *L2InterfacePbbTagRewrite) (*L2InterfacePbbTagRewriteReply, error) {
@@ -262,7 +262,7 @@ func (c *serviceClient) L2InterfacePbbTagRewrite(ctx context.Context, in *L2Inte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2InterfaceVlanTagRewrite(ctx context.Context, in *L2InterfaceVlanTagRewrite) (*L2InterfaceVlanTagRewriteReply, error) {
@@ -271,7 +271,7 @@ func (c *serviceClient) L2InterfaceVlanTagRewrite(ctx context.Context, in *L2Int
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2PatchAddDel(ctx context.Context, in *L2PatchAddDel) (*L2PatchAddDelReply, error) {
@@ -280,7 +280,7 @@ func (c *serviceClient) L2PatchAddDel(ctx context.Context, in *L2PatchAddDel) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2XconnectDump(ctx context.Context, in *L2XconnectDump) (RPCService_L2XconnectDumpClient, error) {
@@ -328,7 +328,7 @@ func (c *serviceClient) L2fibAddDel(ctx context.Context, in *L2fibAddDel) (*L2fi
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2fibFlushAll(ctx context.Context, in *L2fibFlushAll) (*L2fibFlushAllReply, error) {
@@ -337,7 +337,7 @@ func (c *serviceClient) L2fibFlushAll(ctx context.Context, in *L2fibFlushAll) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2fibFlushBd(ctx context.Context, in *L2fibFlushBd) (*L2fibFlushBdReply, error) {
@@ -346,7 +346,7 @@ func (c *serviceClient) L2fibFlushBd(ctx context.Context, in *L2fibFlushBd) (*L2
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2fibFlushInt(ctx context.Context, in *L2fibFlushInt) (*L2fibFlushIntReply, error) {
@@ -355,7 +355,7 @@ func (c *serviceClient) L2fibFlushInt(ctx context.Context, in *L2fibFlushInt) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetL2Bridge(ctx context.Context, in *SwInterfaceSetL2Bridge) (*SwInterfaceSetL2BridgeReply, error) {
@@ -364,7 +364,7 @@ func (c *serviceClient) SwInterfaceSetL2Bridge(ctx context.Context, in *SwInterf
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetL2Xconnect(ctx context.Context, in *SwInterfaceSetL2Xconnect) (*SwInterfaceSetL2XconnectReply, error) {
@@ -373,7 +373,7 @@ func (c *serviceClient) SwInterfaceSetL2Xconnect(ctx context.Context, in *SwInte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetVpath(ctx context.Context, in *SwInterfaceSetVpath) (*SwInterfaceSetVpathReply, error) {
@@ -382,7 +382,7 @@ func (c *serviceClient) SwInterfaceSetVpath(ctx context.Context, in *SwInterface
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) WantL2ArpTermEvents(ctx context.Context, in *WantL2ArpTermEvents) (*WantL2ArpTermEventsReply, error) {
@@ -391,7 +391,7 @@ func (c *serviceClient) WantL2ArpTermEvents(ctx context.Context, in *WantL2ArpTe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) WantL2MacsEvents(ctx context.Context, in *WantL2MacsEvents) (*WantL2MacsEventsReply, error) {
@@ -400,5 +400,5 @@ func (c *serviceClient) WantL2MacsEvents(ctx context.Context, in *WantL2MacsEven
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/l2e/l2e.ba.go b/binapi/l2e/l2e.ba.go
index c1b2a76..7bf5186 100644
--- a/binapi/l2e/l2e.ba.go
+++ b/binapi/l2e/l2e.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/l2e.api.json
 
 // Package l2e contains generated bindings for API file l2e.api.
diff --git a/binapi/l2e/l2e_rest.ba.go b/binapi/l2e/l2e_rest.ba.go
deleted file mode 100644
index 23bc249..0000000
--- a/binapi/l2e/l2e_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package l2e
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/l2_emulation", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2Emulation)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2Emulation(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/l2e/l2e_rpc.ba.go b/binapi/l2e/l2e_rpc.ba.go
index 8f85177..277e04e 100644
--- a/binapi/l2e/l2e_rpc.ba.go
+++ b/binapi/l2e/l2e_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  l2e.
+// RPCService defines RPC service l2e.
 type RPCService interface {
 	L2Emulation(ctx context.Context, in *L2Emulation) (*L2EmulationReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) L2Emulation(ctx context.Context, in *L2Emulation) (*L2Em
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/l2tp/l2tp.ba.go b/binapi/l2tp/l2tp.ba.go
index 574598e..cf93f79 100644
--- a/binapi/l2tp/l2tp.ba.go
+++ b/binapi/l2tp/l2tp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/l2tp.api.json
 
 // Package l2tp contains generated bindings for API file l2tp.api.
diff --git a/binapi/l2tp/l2tp_rest.ba.go b/binapi/l2tp/l2tp_rest.ba.go
deleted file mode 100644
index ac1119f..0000000
--- a/binapi/l2tp/l2tp_rest.ba.go
+++ /dev/null
@@ -1,106 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package l2tp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/l2tpv3_create_tunnel", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2tpv3CreateTunnel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2tpv3CreateTunnel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2tpv3_interface_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2tpv3InterfaceEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2tpv3InterfaceEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2tpv3_set_lookup_key", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2tpv3SetLookupKey)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2tpv3SetLookupKey(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l2tpv3_set_tunnel_cookies", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L2tpv3SetTunnelCookies)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L2tpv3SetTunnelCookies(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/l2tp/l2tp_rpc.ba.go b/binapi/l2tp/l2tp_rpc.ba.go
index 24e62bc..e82ae3d 100644
--- a/binapi/l2tp/l2tp_rpc.ba.go
+++ b/binapi/l2tp/l2tp_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  l2tp.
+// RPCService defines RPC service l2tp.
 type RPCService interface {
 	L2tpv3CreateTunnel(ctx context.Context, in *L2tpv3CreateTunnel) (*L2tpv3CreateTunnelReply, error)
 	L2tpv3InterfaceEnableDisable(ctx context.Context, in *L2tpv3InterfaceEnableDisable) (*L2tpv3InterfaceEnableDisableReply, error)
@@ -34,7 +34,7 @@ func (c *serviceClient) L2tpv3CreateTunnel(ctx context.Context, in *L2tpv3Create
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2tpv3InterfaceEnableDisable(ctx context.Context, in *L2tpv3InterfaceEnableDisable) (*L2tpv3InterfaceEnableDisableReply, error) {
@@ -43,7 +43,7 @@ func (c *serviceClient) L2tpv3InterfaceEnableDisable(ctx context.Context, in *L2
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2tpv3SetLookupKey(ctx context.Context, in *L2tpv3SetLookupKey) (*L2tpv3SetLookupKeyReply, error) {
@@ -52,7 +52,7 @@ func (c *serviceClient) L2tpv3SetLookupKey(ctx context.Context, in *L2tpv3SetLoo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L2tpv3SetTunnelCookies(ctx context.Context, in *L2tpv3SetTunnelCookies) (*L2tpv3SetTunnelCookiesReply, error) {
@@ -61,7 +61,7 @@ func (c *serviceClient) L2tpv3SetTunnelCookies(ctx context.Context, in *L2tpv3Se
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwIfL2tpv3TunnelDump(ctx context.Context, in *SwIfL2tpv3TunnelDump) (RPCService_SwIfL2tpv3TunnelDumpClient, error) {
diff --git a/binapi/l3xc/l3xc.ba.go b/binapi/l3xc/l3xc.ba.go
index 3dbcfba..ac35157 100644
--- a/binapi/l3xc/l3xc.ba.go
+++ b/binapi/l3xc/l3xc.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/l3xc.api.json
 
 // Package l3xc contains generated bindings for API file l3xc.api.
diff --git a/binapi/l3xc/l3xc_rest.ba.go b/binapi/l3xc/l3xc_rest.ba.go
deleted file mode 100644
index 2b2c9ba..0000000
--- a/binapi/l3xc/l3xc_rest.ba.go
+++ /dev/null
@@ -1,74 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package l3xc
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/l3xc_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L3xcDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L3xcDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l3xc_plugin_get_version", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L3xcPluginGetVersion)
-		reply, err := rpc.L3xcPluginGetVersion(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/l3xc_update", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(L3xcUpdate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.L3xcUpdate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/l3xc/l3xc_rpc.ba.go b/binapi/l3xc/l3xc_rpc.ba.go
index ffd0ff8..d463513 100644
--- a/binapi/l3xc/l3xc_rpc.ba.go
+++ b/binapi/l3xc/l3xc_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  l3xc.
+// RPCService defines RPC service l3xc.
 type RPCService interface {
 	L3xcDel(ctx context.Context, in *L3xcDel) (*L3xcDelReply, error)
 	L3xcDump(ctx context.Context, in *L3xcDump) (RPCService_L3xcDumpClient, error)
@@ -33,7 +33,7 @@ func (c *serviceClient) L3xcDel(ctx context.Context, in *L3xcDel) (*L3xcDelReply
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) L3xcDump(ctx context.Context, in *L3xcDump) (RPCService_L3xcDumpClient, error) {
@@ -90,5 +90,5 @@ func (c *serviceClient) L3xcUpdate(ctx context.Context, in *L3xcUpdate) (*L3xcUp
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/lacp/lacp.ba.go b/binapi/lacp/lacp.ba.go
index f1a9457..29ad103 100644
--- a/binapi/lacp/lacp.ba.go
+++ b/binapi/lacp/lacp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/lacp.api.json
 
 // Package lacp contains generated bindings for API file lacp.api.
diff --git a/binapi/lacp/lacp_rest.ba.go b/binapi/lacp/lacp_rest.ba.go
deleted file mode 100644
index 3512a0d..0000000
--- a/binapi/lacp/lacp_rest.ba.go
+++ /dev/null
@@ -1,12 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package lacp
-
-import (
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/lacp/lacp_rpc.ba.go b/binapi/lacp/lacp_rpc.ba.go
index e342a2c..8a288f2 100644
--- a/binapi/lacp/lacp_rpc.ba.go
+++ b/binapi/lacp/lacp_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  lacp.
+// RPCService defines RPC service lacp.
 type RPCService interface {
 	SwInterfaceLacpDump(ctx context.Context, in *SwInterfaceLacpDump) (RPCService_SwInterfaceLacpDumpClient, error)
 }
diff --git a/binapi/lb/lb.ba.go b/binapi/lb/lb.ba.go
index 9fdfc7f..0349d86 100644
--- a/binapi/lb/lb.ba.go
+++ b/binapi/lb/lb.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/lb.api.json
 
 // Package lb contains generated bindings for API file lb.api.
diff --git a/binapi/lb/lb_rest.ba.go b/binapi/lb/lb_rest.ba.go
deleted file mode 100644
index ea7fad8..0000000
--- a/binapi/lb/lb_rest.ba.go
+++ /dev/null
@@ -1,152 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package lb
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/lb_add_del_as", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LbAddDelAs)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LbAddDelAs(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lb_add_del_intf_nat4", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LbAddDelIntfNat4)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LbAddDelIntfNat4(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lb_add_del_intf_nat6", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LbAddDelIntfNat6)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LbAddDelIntfNat6(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lb_add_del_vip", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LbAddDelVip)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LbAddDelVip(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lb_conf", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LbConf)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LbConf(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lb_flush_vip", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LbFlushVip)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LbFlushVip(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/lb/lb_rpc.ba.go b/binapi/lb/lb_rpc.ba.go
index 72b027a..fe0dd7b 100644
--- a/binapi/lb/lb_rpc.ba.go
+++ b/binapi/lb/lb_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  lb.
+// RPCService defines RPC service lb.
 type RPCService interface {
 	LbAddDelAs(ctx context.Context, in *LbAddDelAs) (*LbAddDelAsReply, error)
 	LbAddDelIntfNat4(ctx context.Context, in *LbAddDelIntfNat4) (*LbAddDelIntfNat4Reply, error)
@@ -37,7 +37,7 @@ func (c *serviceClient) LbAddDelAs(ctx context.Context, in *LbAddDelAs) (*LbAddD
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LbAddDelIntfNat4(ctx context.Context, in *LbAddDelIntfNat4) (*LbAddDelIntfNat4Reply, error) {
@@ -46,7 +46,7 @@ func (c *serviceClient) LbAddDelIntfNat4(ctx context.Context, in *LbAddDelIntfNa
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LbAddDelIntfNat6(ctx context.Context, in *LbAddDelIntfNat6) (*LbAddDelIntfNat6Reply, error) {
@@ -55,7 +55,7 @@ func (c *serviceClient) LbAddDelIntfNat6(ctx context.Context, in *LbAddDelIntfNa
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LbAddDelVip(ctx context.Context, in *LbAddDelVip) (*LbAddDelVipReply, error) {
@@ -64,7 +64,7 @@ func (c *serviceClient) LbAddDelVip(ctx context.Context, in *LbAddDelVip) (*LbAd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LbAsDump(ctx context.Context, in *LbAsDump) (RPCService_LbAsDumpClient, error) {
@@ -112,7 +112,7 @@ func (c *serviceClient) LbConf(ctx context.Context, in *LbConf) (*LbConfReply, e
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LbFlushVip(ctx context.Context, in *LbFlushVip) (*LbFlushVipReply, error) {
@@ -121,7 +121,7 @@ func (c *serviceClient) LbFlushVip(ctx context.Context, in *LbFlushVip) (*LbFlus
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LbVipDump(ctx context.Context, in *LbVipDump) (RPCService_LbVipDumpClient, error) {
diff --git a/binapi/lb_types/lb_types.ba.go b/binapi/lb_types/lb_types.ba.go
index 7e41146..6b91100 100644
--- a/binapi/lb_types/lb_types.ba.go
+++ b/binapi/lb_types/lb_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/lb_types.api.json
 
 // Package lb_types contains generated bindings for API file lb_types.api.
diff --git a/binapi/lisp/lisp.ba.go b/binapi/lisp/lisp.ba.go
index 7be6cca..c6e2246 100644
--- a/binapi/lisp/lisp.ba.go
+++ b/binapi/lisp/lisp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/lisp.api.json
 
 // Package lisp contains generated bindings for API file lisp.api.
diff --git a/binapi/lisp/lisp_rest.ba.go b/binapi/lisp/lisp_rest.ba.go
deleted file mode 100644
index 024d6f5..0000000
--- a/binapi/lisp/lisp_rest.ba.go
+++ /dev/null
@@ -1,480 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package lisp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/lisp_add_del_adjacency", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispAddDelAdjacency)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispAddDelAdjacency(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_add_del_local_eid", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispAddDelLocalEid)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispAddDelLocalEid(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_add_del_locator", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispAddDelLocator)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispAddDelLocator(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_add_del_locator_set", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispAddDelLocatorSet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispAddDelLocatorSet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_add_del_map_request_itr_rlocs", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispAddDelMapRequestItrRlocs)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispAddDelMapRequestItrRlocs(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_add_del_map_resolver", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispAddDelMapResolver)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispAddDelMapResolver(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_add_del_map_server", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispAddDelMapServer)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispAddDelMapServer(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_add_del_remote_mapping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispAddDelRemoteMapping)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispAddDelRemoteMapping(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_adjacencies_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispAdjacenciesGet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispAdjacenciesGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_eid_table_add_del_map", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispEidTableAddDelMap)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispEidTableAddDelMap(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_get_map_request_itr_rlocs", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispGetMapRequestItrRlocs)
-		reply, err := rpc.LispGetMapRequestItrRlocs(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_map_register_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispMapRegisterEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispMapRegisterEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_map_request_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispMapRequestMode)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispMapRequestMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_pitr_set_locator_set", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispPitrSetLocatorSet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispPitrSetLocatorSet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_rloc_probe_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispRlocProbeEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispRlocProbeEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/lisp_use_petr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LispUsePetr)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LispUsePetr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_lisp_map_register_state", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowLispMapRegisterState)
-		reply, err := rpc.ShowLispMapRegisterState(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_lisp_map_request_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowLispMapRequestMode)
-		reply, err := rpc.ShowLispMapRequestMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_lisp_pitr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowLispPitr)
-		reply, err := rpc.ShowLispPitr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_lisp_rloc_probe_state", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowLispRlocProbeState)
-		reply, err := rpc.ShowLispRlocProbeState(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_lisp_status", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowLispStatus)
-		reply, err := rpc.ShowLispStatus(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_lisp_use_petr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowLispUsePetr)
-		reply, err := rpc.ShowLispUsePetr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/lisp/lisp_rpc.ba.go b/binapi/lisp/lisp_rpc.ba.go
index 58962d4..511de34 100644
--- a/binapi/lisp/lisp_rpc.ba.go
+++ b/binapi/lisp/lisp_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  lisp.
+// RPCService defines RPC service lisp.
 type RPCService interface {
 	LispAddDelAdjacency(ctx context.Context, in *LispAddDelAdjacency) (*LispAddDelAdjacencyReply, error)
 	LispAddDelLocalEid(ctx context.Context, in *LispAddDelLocalEid) (*LispAddDelLocalEidReply, error)
@@ -59,7 +59,7 @@ func (c *serviceClient) LispAddDelAdjacency(ctx context.Context, in *LispAddDelA
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispAddDelLocalEid(ctx context.Context, in *LispAddDelLocalEid) (*LispAddDelLocalEidReply, error) {
@@ -68,7 +68,7 @@ func (c *serviceClient) LispAddDelLocalEid(ctx context.Context, in *LispAddDelLo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispAddDelLocator(ctx context.Context, in *LispAddDelLocator) (*LispAddDelLocatorReply, error) {
@@ -77,7 +77,7 @@ func (c *serviceClient) LispAddDelLocator(ctx context.Context, in *LispAddDelLoc
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispAddDelLocatorSet(ctx context.Context, in *LispAddDelLocatorSet) (*LispAddDelLocatorSetReply, error) {
@@ -86,7 +86,7 @@ func (c *serviceClient) LispAddDelLocatorSet(ctx context.Context, in *LispAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispAddDelMapRequestItrRlocs(ctx context.Context, in *LispAddDelMapRequestItrRlocs) (*LispAddDelMapRequestItrRlocsReply, error) {
@@ -95,7 +95,7 @@ func (c *serviceClient) LispAddDelMapRequestItrRlocs(ctx context.Context, in *Li
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispAddDelMapResolver(ctx context.Context, in *LispAddDelMapResolver) (*LispAddDelMapResolverReply, error) {
@@ -104,7 +104,7 @@ func (c *serviceClient) LispAddDelMapResolver(ctx context.Context, in *LispAddDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispAddDelMapServer(ctx context.Context, in *LispAddDelMapServer) (*LispAddDelMapServerReply, error) {
@@ -113,7 +113,7 @@ func (c *serviceClient) LispAddDelMapServer(ctx context.Context, in *LispAddDelM
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispAddDelRemoteMapping(ctx context.Context, in *LispAddDelRemoteMapping) (*LispAddDelRemoteMappingReply, error) {
@@ -122,7 +122,7 @@ func (c *serviceClient) LispAddDelRemoteMapping(ctx context.Context, in *LispAdd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispAdjacenciesGet(ctx context.Context, in *LispAdjacenciesGet) (*LispAdjacenciesGetReply, error) {
@@ -131,7 +131,7 @@ func (c *serviceClient) LispAdjacenciesGet(ctx context.Context, in *LispAdjacenc
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispEidTableAddDelMap(ctx context.Context, in *LispEidTableAddDelMap) (*LispEidTableAddDelMapReply, error) {
@@ -140,7 +140,7 @@ func (c *serviceClient) LispEidTableAddDelMap(ctx context.Context, in *LispEidTa
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispEidTableDump(ctx context.Context, in *LispEidTableDump) (RPCService_LispEidTableDumpClient, error) {
@@ -266,7 +266,7 @@ func (c *serviceClient) LispEnableDisable(ctx context.Context, in *LispEnableDis
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispGetMapRequestItrRlocs(ctx context.Context, in *LispGetMapRequestItrRlocs) (*LispGetMapRequestItrRlocsReply, error) {
@@ -275,7 +275,7 @@ func (c *serviceClient) LispGetMapRequestItrRlocs(ctx context.Context, in *LispG
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispLocatorDump(ctx context.Context, in *LispLocatorDump) (RPCService_LispLocatorDumpClient, error) {
@@ -362,7 +362,7 @@ func (c *serviceClient) LispMapRegisterEnableDisable(ctx context.Context, in *Li
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispMapRequestMode(ctx context.Context, in *LispMapRequestMode) (*LispMapRequestModeReply, error) {
@@ -371,7 +371,7 @@ func (c *serviceClient) LispMapRequestMode(ctx context.Context, in *LispMapReque
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispMapResolverDump(ctx context.Context, in *LispMapResolverDump) (RPCService_LispMapResolverDumpClient, error) {
@@ -458,7 +458,7 @@ func (c *serviceClient) LispPitrSetLocatorSet(ctx context.Context, in *LispPitrS
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispRlocProbeEnableDisable(ctx context.Context, in *LispRlocProbeEnableDisable) (*LispRlocProbeEnableDisableReply, error) {
@@ -467,7 +467,7 @@ func (c *serviceClient) LispRlocProbeEnableDisable(ctx context.Context, in *Lisp
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LispUsePetr(ctx context.Context, in *LispUsePetr) (*LispUsePetrReply, error) {
@@ -476,7 +476,7 @@ func (c *serviceClient) LispUsePetr(ctx context.Context, in *LispUsePetr) (*Lisp
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowLispMapRegisterState(ctx context.Context, in *ShowLispMapRegisterState) (*ShowLispMapRegisterStateReply, error) {
@@ -485,7 +485,7 @@ func (c *serviceClient) ShowLispMapRegisterState(ctx context.Context, in *ShowLi
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowLispMapRequestMode(ctx context.Context, in *ShowLispMapRequestMode) (*ShowLispMapRequestModeReply, error) {
@@ -494,7 +494,7 @@ func (c *serviceClient) ShowLispMapRequestMode(ctx context.Context, in *ShowLisp
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowLispPitr(ctx context.Context, in *ShowLispPitr) (*ShowLispPitrReply, error) {
@@ -503,7 +503,7 @@ func (c *serviceClient) ShowLispPitr(ctx context.Context, in *ShowLispPitr) (*Sh
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowLispRlocProbeState(ctx context.Context, in *ShowLispRlocProbeState) (*ShowLispRlocProbeStateReply, error) {
@@ -512,7 +512,7 @@ func (c *serviceClient) ShowLispRlocProbeState(ctx context.Context, in *ShowLisp
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowLispStatus(ctx context.Context, in *ShowLispStatus) (*ShowLispStatusReply, error) {
@@ -521,7 +521,7 @@ func (c *serviceClient) ShowLispStatus(ctx context.Context, in *ShowLispStatus)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowLispUsePetr(ctx context.Context, in *ShowLispUsePetr) (*ShowLispUsePetrReply, error) {
@@ -530,5 +530,5 @@ func (c *serviceClient) ShowLispUsePetr(ctx context.Context, in *ShowLispUsePetr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/lisp_gpe/lisp_gpe.ba.go b/binapi/lisp_gpe/lisp_gpe.ba.go
index 5106c84..91cb715 100644
--- a/binapi/lisp_gpe/lisp_gpe.ba.go
+++ b/binapi/lisp_gpe/lisp_gpe.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/lisp_gpe.api.json
 
 // Package lisp_gpe contains generated bindings for API file lisp_gpe.api.
diff --git a/binapi/lisp_gpe/lisp_gpe_rest.ba.go b/binapi/lisp_gpe/lisp_gpe_rest.ba.go
deleted file mode 100644
index 498b211..0000000
--- a/binapi/lisp_gpe/lisp_gpe_rest.ba.go
+++ /dev/null
@@ -1,203 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package lisp_gpe
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/gpe_add_del_fwd_entry", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GpeAddDelFwdEntry)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GpeAddDelFwdEntry(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gpe_add_del_iface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GpeAddDelIface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GpeAddDelIface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gpe_add_del_native_fwd_rpath", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GpeAddDelNativeFwdRpath)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GpeAddDelNativeFwdRpath(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gpe_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GpeEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GpeEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gpe_fwd_entries_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GpeFwdEntriesGet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GpeFwdEntriesGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gpe_fwd_entry_vnis_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GpeFwdEntryVnisGet)
-		reply, err := rpc.GpeFwdEntryVnisGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gpe_get_encap_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GpeGetEncapMode)
-		reply, err := rpc.GpeGetEncapMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gpe_native_fwd_rpaths_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GpeNativeFwdRpathsGet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GpeNativeFwdRpathsGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/gpe_set_encap_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GpeSetEncapMode)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GpeSetEncapMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/lisp_gpe/lisp_gpe_rpc.ba.go b/binapi/lisp_gpe/lisp_gpe_rpc.ba.go
index 5f33358..872c8cd 100644
--- a/binapi/lisp_gpe/lisp_gpe_rpc.ba.go
+++ b/binapi/lisp_gpe/lisp_gpe_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  lisp_gpe.
+// RPCService defines RPC service lisp_gpe.
 type RPCService interface {
 	GpeAddDelFwdEntry(ctx context.Context, in *GpeAddDelFwdEntry) (*GpeAddDelFwdEntryReply, error)
 	GpeAddDelIface(ctx context.Context, in *GpeAddDelIface) (*GpeAddDelIfaceReply, error)
@@ -39,7 +39,7 @@ func (c *serviceClient) GpeAddDelFwdEntry(ctx context.Context, in *GpeAddDelFwdE
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GpeAddDelIface(ctx context.Context, in *GpeAddDelIface) (*GpeAddDelIfaceReply, error) {
@@ -48,7 +48,7 @@ func (c *serviceClient) GpeAddDelIface(ctx context.Context, in *GpeAddDelIface)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GpeAddDelNativeFwdRpath(ctx context.Context, in *GpeAddDelNativeFwdRpath) (*GpeAddDelNativeFwdRpathReply, error) {
@@ -57,7 +57,7 @@ func (c *serviceClient) GpeAddDelNativeFwdRpath(ctx context.Context, in *GpeAddD
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GpeEnableDisable(ctx context.Context, in *GpeEnableDisable) (*GpeEnableDisableReply, error) {
@@ -66,7 +66,7 @@ func (c *serviceClient) GpeEnableDisable(ctx context.Context, in *GpeEnableDisab
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GpeFwdEntriesGet(ctx context.Context, in *GpeFwdEntriesGet) (*GpeFwdEntriesGetReply, error) {
@@ -75,7 +75,7 @@ func (c *serviceClient) GpeFwdEntriesGet(ctx context.Context, in *GpeFwdEntriesG
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GpeFwdEntryPathDump(ctx context.Context, in *GpeFwdEntryPathDump) (RPCService_GpeFwdEntryPathDumpClient, error) {
@@ -123,7 +123,7 @@ func (c *serviceClient) GpeFwdEntryVnisGet(ctx context.Context, in *GpeFwdEntryV
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GpeGetEncapMode(ctx context.Context, in *GpeGetEncapMode) (*GpeGetEncapModeReply, error) {
@@ -132,7 +132,7 @@ func (c *serviceClient) GpeGetEncapMode(ctx context.Context, in *GpeGetEncapMode
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GpeNativeFwdRpathsGet(ctx context.Context, in *GpeNativeFwdRpathsGet) (*GpeNativeFwdRpathsGetReply, error) {
@@ -141,7 +141,7 @@ func (c *serviceClient) GpeNativeFwdRpathsGet(ctx context.Context, in *GpeNative
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GpeSetEncapMode(ctx context.Context, in *GpeSetEncapMode) (*GpeSetEncapModeReply, error) {
@@ -150,5 +150,5 @@ func (c *serviceClient) GpeSetEncapMode(ctx context.Context, in *GpeSetEncapMode
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/lisp_types/lisp_types.ba.go b/binapi/lisp_types/lisp_types.ba.go
index a7302f2..1af3a26 100644
--- a/binapi/lisp_types/lisp_types.ba.go
+++ b/binapi/lisp_types/lisp_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/lisp_types.api.json
 
 // Package lisp_types contains generated bindings for API file lisp_types.api.
diff --git a/binapi/lldp/lldp.ba.go b/binapi/lldp/lldp.ba.go
index a8769b5..6ae1ae7 100644
--- a/binapi/lldp/lldp.ba.go
+++ b/binapi/lldp/lldp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/lldp.api.json
 
 // Package lldp contains generated bindings for API file lldp.api.
diff --git a/binapi/lldp/lldp_rest.ba.go b/binapi/lldp/lldp_rest.ba.go
deleted file mode 100644
index 807ef94..0000000
--- a/binapi/lldp/lldp_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package lldp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/lldp_config", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(LldpConfig)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.LldpConfig(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_lldp", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetLldp)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetLldp(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/lldp/lldp_rpc.ba.go b/binapi/lldp/lldp_rpc.ba.go
index 359039f..d9fdbc5 100644
--- a/binapi/lldp/lldp_rpc.ba.go
+++ b/binapi/lldp/lldp_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  lldp.
+// RPCService defines RPC service lldp.
 type RPCService interface {
 	LldpConfig(ctx context.Context, in *LldpConfig) (*LldpConfigReply, error)
 	SwInterfaceSetLldp(ctx context.Context, in *SwInterfaceSetLldp) (*SwInterfaceSetLldpReply, error)
@@ -28,7 +28,7 @@ func (c *serviceClient) LldpConfig(ctx context.Context, in *LldpConfig) (*LldpCo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceSetLldp(ctx context.Context, in *SwInterfaceSetLldp) (*SwInterfaceSetLldpReply, error) {
@@ -37,5 +37,5 @@ func (c *serviceClient) SwInterfaceSetLldp(ctx context.Context, in *SwInterfaceS
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/mactime/mactime.ba.go b/binapi/mactime/mactime.ba.go
index deb7472..4c95735 100644
--- a/binapi/mactime/mactime.ba.go
+++ b/binapi/mactime/mactime.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/mactime.api.json
 
 // Package mactime contains generated bindings for API file mactime.api.
diff --git a/binapi/mactime/mactime_rest.ba.go b/binapi/mactime/mactime_rest.ba.go
deleted file mode 100644
index 4318dbc..0000000
--- a/binapi/mactime/mactime_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package mactime
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/mactime_add_del_range", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MactimeAddDelRange)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MactimeAddDelRange(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/mactime_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MactimeEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MactimeEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/mactime/mactime_rpc.ba.go b/binapi/mactime/mactime_rpc.ba.go
index 0273feb..ddde52b 100644
--- a/binapi/mactime/mactime_rpc.ba.go
+++ b/binapi/mactime/mactime_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  mactime.
+// RPCService defines RPC service mactime.
 type RPCService interface {
 	MactimeAddDelRange(ctx context.Context, in *MactimeAddDelRange) (*MactimeAddDelRangeReply, error)
 	MactimeDump(ctx context.Context, in *MactimeDump) (RPCService_MactimeDumpClient, error)
@@ -32,7 +32,7 @@ func (c *serviceClient) MactimeAddDelRange(ctx context.Context, in *MactimeAddDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MactimeDump(ctx context.Context, in *MactimeDump) (RPCService_MactimeDumpClient, error) {
@@ -80,5 +80,5 @@ func (c *serviceClient) MactimeEnableDisable(ctx context.Context, in *MactimeEna
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/map/map.ba.go b/binapi/map/map.ba.go
index b906284..aeb8cf7 100644
--- a/binapi/map/map.ba.go
+++ b/binapi/map/map.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/map.api.json
 
 // Package maps contains generated bindings for API file map.api.
diff --git a/binapi/map/map_rest.ba.go b/binapi/map/map_rest.ba.go
deleted file mode 100644
index 922acb5..0000000
--- a/binapi/map/map_rest.ba.go
+++ /dev/null
@@ -1,295 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package maps
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/map_add_del_rule", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapAddDelRule)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapAddDelRule(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_add_domain", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapAddDomain)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapAddDomain(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_del_domain", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapDelDomain)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapDelDomain(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_if_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapIfEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapIfEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_param_add_del_pre_resolve", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapParamAddDelPreResolve)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapParamAddDelPreResolve(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_param_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapParamGet)
-		reply, err := rpc.MapParamGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_param_set_fragmentation", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapParamSetFragmentation)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapParamSetFragmentation(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_param_set_icmp", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapParamSetICMP)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapParamSetICMP(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_param_set_icmp6", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapParamSetICMP6)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapParamSetICMP6(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_param_set_security_check", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapParamSetSecurityCheck)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapParamSetSecurityCheck(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_param_set_tcp", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapParamSetTCP)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapParamSetTCP(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_param_set_traffic_class", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapParamSetTrafficClass)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MapParamSetTrafficClass(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/map_summary_stats", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MapSummaryStats)
-		reply, err := rpc.MapSummaryStats(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/map/map_rpc.ba.go b/binapi/map/map_rpc.ba.go
index f45dbe5..8c20779 100644
--- a/binapi/map/map_rpc.ba.go
+++ b/binapi/map/map_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  map.
+// RPCService defines RPC service map.
 type RPCService interface {
 	MapAddDelRule(ctx context.Context, in *MapAddDelRule) (*MapAddDelRuleReply, error)
 	MapAddDomain(ctx context.Context, in *MapAddDomain) (*MapAddDomainReply, error)
@@ -44,7 +44,7 @@ func (c *serviceClient) MapAddDelRule(ctx context.Context, in *MapAddDelRule) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapAddDomain(ctx context.Context, in *MapAddDomain) (*MapAddDomainReply, error) {
@@ -53,7 +53,7 @@ func (c *serviceClient) MapAddDomain(ctx context.Context, in *MapAddDomain) (*Ma
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapDelDomain(ctx context.Context, in *MapDelDomain) (*MapDelDomainReply, error) {
@@ -62,7 +62,7 @@ func (c *serviceClient) MapDelDomain(ctx context.Context, in *MapDelDomain) (*Ma
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapDomainDump(ctx context.Context, in *MapDomainDump) (RPCService_MapDomainDumpClient, error) {
@@ -110,7 +110,7 @@ func (c *serviceClient) MapIfEnableDisable(ctx context.Context, in *MapIfEnableD
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapParamAddDelPreResolve(ctx context.Context, in *MapParamAddDelPreResolve) (*MapParamAddDelPreResolveReply, error) {
@@ -119,7 +119,7 @@ func (c *serviceClient) MapParamAddDelPreResolve(ctx context.Context, in *MapPar
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapParamGet(ctx context.Context, in *MapParamGet) (*MapParamGetReply, error) {
@@ -128,7 +128,7 @@ func (c *serviceClient) MapParamGet(ctx context.Context, in *MapParamGet) (*MapP
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapParamSetFragmentation(ctx context.Context, in *MapParamSetFragmentation) (*MapParamSetFragmentationReply, error) {
@@ -137,7 +137,7 @@ func (c *serviceClient) MapParamSetFragmentation(ctx context.Context, in *MapPar
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapParamSetICMP(ctx context.Context, in *MapParamSetICMP) (*MapParamSetICMPReply, error) {
@@ -146,7 +146,7 @@ func (c *serviceClient) MapParamSetICMP(ctx context.Context, in *MapParamSetICMP
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapParamSetICMP6(ctx context.Context, in *MapParamSetICMP6) (*MapParamSetICMP6Reply, error) {
@@ -155,7 +155,7 @@ func (c *serviceClient) MapParamSetICMP6(ctx context.Context, in *MapParamSetICM
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapParamSetSecurityCheck(ctx context.Context, in *MapParamSetSecurityCheck) (*MapParamSetSecurityCheckReply, error) {
@@ -164,7 +164,7 @@ func (c *serviceClient) MapParamSetSecurityCheck(ctx context.Context, in *MapPar
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapParamSetTCP(ctx context.Context, in *MapParamSetTCP) (*MapParamSetTCPReply, error) {
@@ -173,7 +173,7 @@ func (c *serviceClient) MapParamSetTCP(ctx context.Context, in *MapParamSetTCP)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapParamSetTrafficClass(ctx context.Context, in *MapParamSetTrafficClass) (*MapParamSetTrafficClassReply, error) {
@@ -182,7 +182,7 @@ func (c *serviceClient) MapParamSetTrafficClass(ctx context.Context, in *MapPara
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MapRuleDump(ctx context.Context, in *MapRuleDump) (RPCService_MapRuleDumpClient, error) {
@@ -230,5 +230,5 @@ func (c *serviceClient) MapSummaryStats(ctx context.Context, in *MapSummaryStats
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/mdata/mdata.ba.go b/binapi/mdata/mdata.ba.go
index d4715f7..a218692 100644
--- a/binapi/mdata/mdata.ba.go
+++ b/binapi/mdata/mdata.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/mdata.api.json
 
 // Package mdata contains generated bindings for API file mdata.api.
diff --git a/binapi/mdata/mdata_rest.ba.go b/binapi/mdata/mdata_rest.ba.go
deleted file mode 100644
index 12b22e7..0000000
--- a/binapi/mdata/mdata_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package mdata
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/mdata_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MdataEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MdataEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/mdata/mdata_rpc.ba.go b/binapi/mdata/mdata_rpc.ba.go
index 28b2589..8ae8748 100644
--- a/binapi/mdata/mdata_rpc.ba.go
+++ b/binapi/mdata/mdata_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  mdata.
+// RPCService defines RPC service mdata.
 type RPCService interface {
 	MdataEnableDisable(ctx context.Context, in *MdataEnableDisable) (*MdataEnableDisableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) MdataEnableDisable(ctx context.Context, in *MdataEnableD
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/memclnt/memclnt.ba.go b/binapi/memclnt/memclnt.ba.go
index 3bbf88d..0dac33f 100644
--- a/binapi/memclnt/memclnt.ba.go
+++ b/binapi/memclnt/memclnt.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/memclnt.api.json
 
 // Package memclnt contains generated bindings for API file memclnt.api.
diff --git a/binapi/memclnt/memclnt_rest.ba.go b/binapi/memclnt/memclnt_rest.ba.go
deleted file mode 100644
index bb409da..0000000
--- a/binapi/memclnt/memclnt_rest.ba.go
+++ /dev/null
@@ -1,203 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package memclnt
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/api_versions", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(APIVersions)
-		reply, err := rpc.APIVersions(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/get_first_msg_id", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GetFirstMsgID)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GetFirstMsgID(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/memclnt_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MemclntCreate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MemclntCreate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/memclnt_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MemclntDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MemclntDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/memclnt_keepalive", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MemclntKeepalive)
-		reply, err := rpc.MemclntKeepalive(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/rpc_call", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(RPCCall)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.RPCCall(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sock_init_shm", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SockInitShm)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SockInitShm(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sockclnt_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SockclntCreate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SockclntCreate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sockclnt_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SockclntDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SockclntDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/memclnt/memclnt_rpc.ba.go b/binapi/memclnt/memclnt_rpc.ba.go
index ae75a36..ef4a1a4 100644
--- a/binapi/memclnt/memclnt_rpc.ba.go
+++ b/binapi/memclnt/memclnt_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  memclnt.
+// RPCService defines RPC service memclnt.
 type RPCService interface {
 	APIVersions(ctx context.Context, in *APIVersions) (*APIVersionsReply, error)
 	GetFirstMsgID(ctx context.Context, in *GetFirstMsgID) (*GetFirstMsgIDReply, error)
@@ -39,7 +39,7 @@ func (c *serviceClient) APIVersions(ctx context.Context, in *APIVersions) (*APIV
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GetFirstMsgID(ctx context.Context, in *GetFirstMsgID) (*GetFirstMsgIDReply, error) {
@@ -48,7 +48,7 @@ func (c *serviceClient) GetFirstMsgID(ctx context.Context, in *GetFirstMsgID) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MemclntCreate(ctx context.Context, in *MemclntCreate) (*MemclntCreateReply, error) {
@@ -75,7 +75,7 @@ func (c *serviceClient) MemclntKeepalive(ctx context.Context, in *MemclntKeepali
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MemclntReadTimeout(ctx context.Context, in *MemclntReadTimeout) error {
@@ -108,7 +108,7 @@ func (c *serviceClient) RPCCall(ctx context.Context, in *RPCCall) (*RPCCallReply
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) RxThreadExit(ctx context.Context, in *RxThreadExit) error {
@@ -129,7 +129,7 @@ func (c *serviceClient) SockInitShm(ctx context.Context, in *SockInitShm) (*Sock
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SockclntCreate(ctx context.Context, in *SockclntCreate) (*SockclntCreateReply, error) {
diff --git a/binapi/memif/memif.ba.go b/binapi/memif/memif.ba.go
index fddd0ab..8a7140b 100644
--- a/binapi/memif/memif.ba.go
+++ b/binapi/memif/memif.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/memif.api.json
 
 // Package memif contains generated bindings for API file memif.api.
diff --git a/binapi/memif/memif_rest.ba.go b/binapi/memif/memif_rest.ba.go
deleted file mode 100644
index 726824f..0000000
--- a/binapi/memif/memif_rest.ba.go
+++ /dev/null
@@ -1,83 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package memif
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/memif_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MemifCreate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MemifCreate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/memif_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MemifDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MemifDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/memif_socket_filename_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MemifSocketFilenameAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MemifSocketFilenameAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/memif/memif_rpc.ba.go b/binapi/memif/memif_rpc.ba.go
index b11f07f..bc1c0e4 100644
--- a/binapi/memif/memif_rpc.ba.go
+++ b/binapi/memif/memif_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  memif.
+// RPCService defines RPC service memif.
 type RPCService interface {
 	MemifCreate(ctx context.Context, in *MemifCreate) (*MemifCreateReply, error)
 	MemifDelete(ctx context.Context, in *MemifDelete) (*MemifDeleteReply, error)
@@ -34,7 +34,7 @@ func (c *serviceClient) MemifCreate(ctx context.Context, in *MemifCreate) (*Memi
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MemifDelete(ctx context.Context, in *MemifDelete) (*MemifDeleteReply, error) {
@@ -43,7 +43,7 @@ func (c *serviceClient) MemifDelete(ctx context.Context, in *MemifDelete) (*Memi
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MemifDump(ctx context.Context, in *MemifDump) (RPCService_MemifDumpClient, error) {
@@ -91,7 +91,7 @@ func (c *serviceClient) MemifSocketFilenameAddDel(ctx context.Context, in *Memif
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MemifSocketFilenameDump(ctx context.Context, in *MemifSocketFilenameDump) (RPCService_MemifSocketFilenameDumpClient, error) {
diff --git a/binapi/mfib_types/mfib_types.ba.go b/binapi/mfib_types/mfib_types.ba.go
index 1d6ddef..41c2434 100644
--- a/binapi/mfib_types/mfib_types.ba.go
+++ b/binapi/mfib_types/mfib_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/mfib_types.api.json
 
 // Package mfib_types contains generated bindings for API file mfib_types.api.
diff --git a/binapi/mpls/mpls.ba.go b/binapi/mpls/mpls.ba.go
index 9443728..799ae69 100644
--- a/binapi/mpls/mpls.ba.go
+++ b/binapi/mpls/mpls.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/mpls.api.json
 
 // Package mpls contains generated bindings for API file mpls.api.
diff --git a/binapi/mpls/mpls_rest.ba.go b/binapi/mpls/mpls_rest.ba.go
deleted file mode 100644
index 9cac11b..0000000
--- a/binapi/mpls/mpls_rest.ba.go
+++ /dev/null
@@ -1,129 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package mpls
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/mpls_ip_bind_unbind", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MplsIPBindUnbind)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MplsIPBindUnbind(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/mpls_route_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MplsRouteAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MplsRouteAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/mpls_table_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MplsTableAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MplsTableAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/mpls_tunnel_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(MplsTunnelAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.MplsTunnelAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sw_interface_set_mpls_enable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetMplsEnable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetMplsEnable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/mpls/mpls_rpc.ba.go b/binapi/mpls/mpls_rpc.ba.go
index 258af4a..bfd6559 100644
--- a/binapi/mpls/mpls_rpc.ba.go
+++ b/binapi/mpls/mpls_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  mpls.
+// RPCService defines RPC service mpls.
 type RPCService interface {
 	MplsIPBindUnbind(ctx context.Context, in *MplsIPBindUnbind) (*MplsIPBindUnbindReply, error)
 	MplsRouteAddDel(ctx context.Context, in *MplsRouteAddDel) (*MplsRouteAddDelReply, error)
@@ -37,7 +37,7 @@ func (c *serviceClient) MplsIPBindUnbind(ctx context.Context, in *MplsIPBindUnbi
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MplsRouteAddDel(ctx context.Context, in *MplsRouteAddDel) (*MplsRouteAddDelReply, error) {
@@ -46,7 +46,7 @@ func (c *serviceClient) MplsRouteAddDel(ctx context.Context, in *MplsRouteAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MplsRouteDump(ctx context.Context, in *MplsRouteDump) (RPCService_MplsRouteDumpClient, error) {
@@ -94,7 +94,7 @@ func (c *serviceClient) MplsTableAddDel(ctx context.Context, in *MplsTableAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MplsTableDump(ctx context.Context, in *MplsTableDump) (RPCService_MplsTableDumpClient, error) {
@@ -142,7 +142,7 @@ func (c *serviceClient) MplsTunnelAddDel(ctx context.Context, in *MplsTunnelAddD
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) MplsTunnelDump(ctx context.Context, in *MplsTunnelDump) (RPCService_MplsTunnelDumpClient, error) {
@@ -190,5 +190,5 @@ func (c *serviceClient) SwInterfaceSetMplsEnable(ctx context.Context, in *SwInte
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/nat/nat.ba.go b/binapi/nat/nat.ba.go
index c21307f..ac65413 100644
--- a/binapi/nat/nat.ba.go
+++ b/binapi/nat/nat.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/nat.api.json
 
 // Package nat contains generated bindings for API file nat.api.
diff --git a/binapi/nat/nat_rest.ba.go b/binapi/nat/nat_rest.ba.go
deleted file mode 100644
index 7740ea1..0000000
--- a/binapi/nat/nat_rest.ba.go
+++ /dev/null
@@ -1,913 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package nat
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/nat44_add_del_address_range", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44AddDelAddressRange)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44AddDelAddressRange(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_add_del_identity_mapping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44AddDelIdentityMapping)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44AddDelIdentityMapping(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_add_del_interface_addr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44AddDelInterfaceAddr)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44AddDelInterfaceAddr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_add_del_lb_static_mapping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44AddDelLbStaticMapping)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44AddDelLbStaticMapping(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_add_del_static_mapping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44AddDelStaticMapping)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44AddDelStaticMapping(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_del_session", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44DelSession)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44DelSession(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_del_user", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44DelUser)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44DelUser(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_forwarding_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44ForwardingEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44ForwardingEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_forwarding_is_enabled", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44ForwardingIsEnabled)
-		reply, err := rpc.Nat44ForwardingIsEnabled(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_interface_add_del_feature", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44InterfaceAddDelFeature)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44InterfaceAddDelFeature(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_interface_add_del_output_feature", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44InterfaceAddDelOutputFeature)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44InterfaceAddDelOutputFeature(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_lb_static_mapping_add_del_local", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44LbStaticMappingAddDelLocal)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44LbStaticMappingAddDelLocal(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_session_cleanup", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44SessionCleanup)
-		reply, err := rpc.Nat44SessionCleanup(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat44_set_session_limit", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat44SetSessionLimit)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat44SetSessionLimit(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat64_add_del_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat64AddDelInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat64AddDelInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat64_add_del_interface_addr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat64AddDelInterfaceAddr)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat64AddDelInterfaceAddr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat64_add_del_pool_addr_range", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat64AddDelPoolAddrRange)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat64AddDelPoolAddrRange(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat64_add_del_prefix", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat64AddDelPrefix)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat64AddDelPrefix(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat64_add_del_static_bib", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat64AddDelStaticBib)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat64AddDelStaticBib(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat66_add_del_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat66AddDelInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat66AddDelInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat66_add_del_static_mapping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Nat66AddDelStaticMapping)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Nat66AddDelStaticMapping(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_control_ping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatControlPing)
-		reply, err := rpc.NatControlPing(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_det_add_del_map", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatDetAddDelMap)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatDetAddDelMap(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_det_close_session_in", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatDetCloseSessionIn)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatDetCloseSessionIn(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_det_close_session_out", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatDetCloseSessionOut)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatDetCloseSessionOut(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_det_forward", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatDetForward)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatDetForward(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_det_reverse", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatDetReverse)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatDetReverse(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_get_addr_and_port_alloc_alg", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatGetAddrAndPortAllocAlg)
-		reply, err := rpc.NatGetAddrAndPortAllocAlg(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_get_mss_clamping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatGetMssClamping)
-		reply, err := rpc.NatGetMssClamping(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_get_timeouts", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatGetTimeouts)
-		reply, err := rpc.NatGetTimeouts(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_ha_flush", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatHaFlush)
-		reply, err := rpc.NatHaFlush(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_ha_get_failover", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatHaGetFailover)
-		reply, err := rpc.NatHaGetFailover(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_ha_get_listener", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatHaGetListener)
-		reply, err := rpc.NatHaGetListener(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_ha_resync", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatHaResync)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatHaResync(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_ha_set_failover", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatHaSetFailover)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatHaSetFailover(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_ha_set_listener", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatHaSetListener)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatHaSetListener(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_ipfix_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatIpfixEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatIpfixEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_set_addr_and_port_alloc_alg", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatSetAddrAndPortAllocAlg)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatSetAddrAndPortAllocAlg(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_set_log_level", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatSetLogLevel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatSetLogLevel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_set_mss_clamping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatSetMssClamping)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatSetMssClamping(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_set_timeouts", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatSetTimeouts)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatSetTimeouts(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_set_workers", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatSetWorkers)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NatSetWorkers(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nat_show_config", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NatShowConfig)
-		reply, err := rpc.NatShowConfig(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/nat/nat_rpc.ba.go b/binapi/nat/nat_rpc.ba.go
index bd07910..9da5e09 100644
--- a/binapi/nat/nat_rpc.ba.go
+++ b/binapi/nat/nat_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  nat.
+// RPCService defines RPC service nat.
 type RPCService interface {
 	Nat44AddDelAddressRange(ctx context.Context, in *Nat44AddDelAddressRange) (*Nat44AddDelAddressRangeReply, error)
 	Nat44AddDelIdentityMapping(ctx context.Context, in *Nat44AddDelIdentityMapping) (*Nat44AddDelIdentityMappingReply, error)
@@ -91,7 +91,7 @@ func (c *serviceClient) Nat44AddDelAddressRange(ctx context.Context, in *Nat44Ad
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44AddDelIdentityMapping(ctx context.Context, in *Nat44AddDelIdentityMapping) (*Nat44AddDelIdentityMappingReply, error) {
@@ -100,7 +100,7 @@ func (c *serviceClient) Nat44AddDelIdentityMapping(ctx context.Context, in *Nat4
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44AddDelInterfaceAddr(ctx context.Context, in *Nat44AddDelInterfaceAddr) (*Nat44AddDelInterfaceAddrReply, error) {
@@ -109,7 +109,7 @@ func (c *serviceClient) Nat44AddDelInterfaceAddr(ctx context.Context, in *Nat44A
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44AddDelLbStaticMapping(ctx context.Context, in *Nat44AddDelLbStaticMapping) (*Nat44AddDelLbStaticMappingReply, error) {
@@ -118,7 +118,7 @@ func (c *serviceClient) Nat44AddDelLbStaticMapping(ctx context.Context, in *Nat4
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44AddDelStaticMapping(ctx context.Context, in *Nat44AddDelStaticMapping) (*Nat44AddDelStaticMappingReply, error) {
@@ -127,7 +127,7 @@ func (c *serviceClient) Nat44AddDelStaticMapping(ctx context.Context, in *Nat44A
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44AddressDump(ctx context.Context, in *Nat44AddressDump) (RPCService_Nat44AddressDumpClient, error) {
@@ -175,7 +175,7 @@ func (c *serviceClient) Nat44DelSession(ctx context.Context, in *Nat44DelSession
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44DelUser(ctx context.Context, in *Nat44DelUser) (*Nat44DelUserReply, error) {
@@ -184,7 +184,7 @@ func (c *serviceClient) Nat44DelUser(ctx context.Context, in *Nat44DelUser) (*Na
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44ForwardingEnableDisable(ctx context.Context, in *Nat44ForwardingEnableDisable) (*Nat44ForwardingEnableDisableReply, error) {
@@ -193,7 +193,7 @@ func (c *serviceClient) Nat44ForwardingEnableDisable(ctx context.Context, in *Na
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44ForwardingIsEnabled(ctx context.Context, in *Nat44ForwardingIsEnabled) (*Nat44ForwardingIsEnabledReply, error) {
@@ -250,7 +250,7 @@ func (c *serviceClient) Nat44InterfaceAddDelFeature(ctx context.Context, in *Nat
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44InterfaceAddDelOutputFeature(ctx context.Context, in *Nat44InterfaceAddDelOutputFeature) (*Nat44InterfaceAddDelOutputFeatureReply, error) {
@@ -259,7 +259,7 @@ func (c *serviceClient) Nat44InterfaceAddDelOutputFeature(ctx context.Context, i
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44InterfaceAddrDump(ctx context.Context, in *Nat44InterfaceAddrDump) (RPCService_Nat44InterfaceAddrDumpClient, error) {
@@ -385,7 +385,7 @@ func (c *serviceClient) Nat44LbStaticMappingAddDelLocal(ctx context.Context, in
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44LbStaticMappingDump(ctx context.Context, in *Nat44LbStaticMappingDump) (RPCService_Nat44LbStaticMappingDumpClient, error) {
@@ -433,7 +433,7 @@ func (c *serviceClient) Nat44SessionCleanup(ctx context.Context, in *Nat44Sessio
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44SetSessionLimit(ctx context.Context, in *Nat44SetSessionLimit) (*Nat44SetSessionLimitReply, error) {
@@ -442,7 +442,7 @@ func (c *serviceClient) Nat44SetSessionLimit(ctx context.Context, in *Nat44SetSe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat44StaticMappingDump(ctx context.Context, in *Nat44StaticMappingDump) (RPCService_Nat44StaticMappingDumpClient, error) {
@@ -568,7 +568,7 @@ func (c *serviceClient) Nat64AddDelInterface(ctx context.Context, in *Nat64AddDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat64AddDelInterfaceAddr(ctx context.Context, in *Nat64AddDelInterfaceAddr) (*Nat64AddDelInterfaceAddrReply, error) {
@@ -577,7 +577,7 @@ func (c *serviceClient) Nat64AddDelInterfaceAddr(ctx context.Context, in *Nat64A
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat64AddDelPoolAddrRange(ctx context.Context, in *Nat64AddDelPoolAddrRange) (*Nat64AddDelPoolAddrRangeReply, error) {
@@ -586,7 +586,7 @@ func (c *serviceClient) Nat64AddDelPoolAddrRange(ctx context.Context, in *Nat64A
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat64AddDelPrefix(ctx context.Context, in *Nat64AddDelPrefix) (*Nat64AddDelPrefixReply, error) {
@@ -595,7 +595,7 @@ func (c *serviceClient) Nat64AddDelPrefix(ctx context.Context, in *Nat64AddDelPr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat64AddDelStaticBib(ctx context.Context, in *Nat64AddDelStaticBib) (*Nat64AddDelStaticBibReply, error) {
@@ -604,7 +604,7 @@ func (c *serviceClient) Nat64AddDelStaticBib(ctx context.Context, in *Nat64AddDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat64BibDump(ctx context.Context, in *Nat64BibDump) (RPCService_Nat64BibDumpClient, error) {
@@ -808,7 +808,7 @@ func (c *serviceClient) Nat66AddDelInterface(ctx context.Context, in *Nat66AddDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat66AddDelStaticMapping(ctx context.Context, in *Nat66AddDelStaticMapping) (*Nat66AddDelStaticMappingReply, error) {
@@ -817,7 +817,7 @@ func (c *serviceClient) Nat66AddDelStaticMapping(ctx context.Context, in *Nat66A
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Nat66InterfaceDump(ctx context.Context, in *Nat66InterfaceDump) (RPCService_Nat66InterfaceDumpClient, error) {
@@ -904,7 +904,7 @@ func (c *serviceClient) NatControlPing(ctx context.Context, in *NatControlPing)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatDetAddDelMap(ctx context.Context, in *NatDetAddDelMap) (*NatDetAddDelMapReply, error) {
@@ -913,7 +913,7 @@ func (c *serviceClient) NatDetAddDelMap(ctx context.Context, in *NatDetAddDelMap
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatDetCloseSessionIn(ctx context.Context, in *NatDetCloseSessionIn) (*NatDetCloseSessionInReply, error) {
@@ -922,7 +922,7 @@ func (c *serviceClient) NatDetCloseSessionIn(ctx context.Context, in *NatDetClos
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatDetCloseSessionOut(ctx context.Context, in *NatDetCloseSessionOut) (*NatDetCloseSessionOutReply, error) {
@@ -931,7 +931,7 @@ func (c *serviceClient) NatDetCloseSessionOut(ctx context.Context, in *NatDetClo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatDetForward(ctx context.Context, in *NatDetForward) (*NatDetForwardReply, error) {
@@ -940,7 +940,7 @@ func (c *serviceClient) NatDetForward(ctx context.Context, in *NatDetForward) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatDetMapDump(ctx context.Context, in *NatDetMapDump) (RPCService_NatDetMapDumpClient, error) {
@@ -988,7 +988,7 @@ func (c *serviceClient) NatDetReverse(ctx context.Context, in *NatDetReverse) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatDetSessionDump(ctx context.Context, in *NatDetSessionDump) (RPCService_NatDetSessionDumpClient, error) {
@@ -1036,7 +1036,7 @@ func (c *serviceClient) NatGetAddrAndPortAllocAlg(ctx context.Context, in *NatGe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatGetMssClamping(ctx context.Context, in *NatGetMssClamping) (*NatGetMssClampingReply, error) {
@@ -1045,7 +1045,7 @@ func (c *serviceClient) NatGetMssClamping(ctx context.Context, in *NatGetMssClam
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatGetTimeouts(ctx context.Context, in *NatGetTimeouts) (*NatGetTimeoutsReply, error) {
@@ -1054,7 +1054,7 @@ func (c *serviceClient) NatGetTimeouts(ctx context.Context, in *NatGetTimeouts)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatHaFlush(ctx context.Context, in *NatHaFlush) (*NatHaFlushReply, error) {
@@ -1063,7 +1063,7 @@ func (c *serviceClient) NatHaFlush(ctx context.Context, in *NatHaFlush) (*NatHaF
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatHaGetFailover(ctx context.Context, in *NatHaGetFailover) (*NatHaGetFailoverReply, error) {
@@ -1072,7 +1072,7 @@ func (c *serviceClient) NatHaGetFailover(ctx context.Context, in *NatHaGetFailov
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatHaGetListener(ctx context.Context, in *NatHaGetListener) (*NatHaGetListenerReply, error) {
@@ -1081,7 +1081,7 @@ func (c *serviceClient) NatHaGetListener(ctx context.Context, in *NatHaGetListen
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatHaResync(ctx context.Context, in *NatHaResync) (*NatHaResyncReply, error) {
@@ -1090,7 +1090,7 @@ func (c *serviceClient) NatHaResync(ctx context.Context, in *NatHaResync) (*NatH
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatHaSetFailover(ctx context.Context, in *NatHaSetFailover) (*NatHaSetFailoverReply, error) {
@@ -1099,7 +1099,7 @@ func (c *serviceClient) NatHaSetFailover(ctx context.Context, in *NatHaSetFailov
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatHaSetListener(ctx context.Context, in *NatHaSetListener) (*NatHaSetListenerReply, error) {
@@ -1108,7 +1108,7 @@ func (c *serviceClient) NatHaSetListener(ctx context.Context, in *NatHaSetListen
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatIpfixEnableDisable(ctx context.Context, in *NatIpfixEnableDisable) (*NatIpfixEnableDisableReply, error) {
@@ -1117,7 +1117,7 @@ func (c *serviceClient) NatIpfixEnableDisable(ctx context.Context, in *NatIpfixE
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatSetAddrAndPortAllocAlg(ctx context.Context, in *NatSetAddrAndPortAllocAlg) (*NatSetAddrAndPortAllocAlgReply, error) {
@@ -1126,7 +1126,7 @@ func (c *serviceClient) NatSetAddrAndPortAllocAlg(ctx context.Context, in *NatSe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatSetLogLevel(ctx context.Context, in *NatSetLogLevel) (*NatSetLogLevelReply, error) {
@@ -1135,7 +1135,7 @@ func (c *serviceClient) NatSetLogLevel(ctx context.Context, in *NatSetLogLevel)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatSetMssClamping(ctx context.Context, in *NatSetMssClamping) (*NatSetMssClampingReply, error) {
@@ -1144,7 +1144,7 @@ func (c *serviceClient) NatSetMssClamping(ctx context.Context, in *NatSetMssClam
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatSetTimeouts(ctx context.Context, in *NatSetTimeouts) (*NatSetTimeoutsReply, error) {
@@ -1153,7 +1153,7 @@ func (c *serviceClient) NatSetTimeouts(ctx context.Context, in *NatSetTimeouts)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatSetWorkers(ctx context.Context, in *NatSetWorkers) (*NatSetWorkersReply, error) {
@@ -1162,7 +1162,7 @@ func (c *serviceClient) NatSetWorkers(ctx context.Context, in *NatSetWorkers) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatShowConfig(ctx context.Context, in *NatShowConfig) (*NatShowConfigReply, error) {
@@ -1171,7 +1171,7 @@ func (c *serviceClient) NatShowConfig(ctx context.Context, in *NatShowConfig) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NatWorkerDump(ctx context.Context, in *NatWorkerDump) (RPCService_NatWorkerDumpClient, error) {
diff --git a/binapi/nsh/nsh.ba.go b/binapi/nsh/nsh.ba.go
index 5897a90..5113a82 100644
--- a/binapi/nsh/nsh.ba.go
+++ b/binapi/nsh/nsh.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/nsh.api.json
 
 // Package nsh contains generated bindings for API file nsh.api.
diff --git a/binapi/nsh/nsh_rest.ba.go b/binapi/nsh/nsh_rest.ba.go
deleted file mode 100644
index 87b29e4..0000000
--- a/binapi/nsh/nsh_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package nsh
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/nsh_add_del_entry", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NshAddDelEntry)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NshAddDelEntry(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nsh_add_del_map", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NshAddDelMap)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NshAddDelMap(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/nsh/nsh_rpc.ba.go b/binapi/nsh/nsh_rpc.ba.go
index 320aa9f..db79b4f 100644
--- a/binapi/nsh/nsh_rpc.ba.go
+++ b/binapi/nsh/nsh_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  nsh.
+// RPCService defines RPC service nsh.
 type RPCService interface {
 	NshAddDelEntry(ctx context.Context, in *NshAddDelEntry) (*NshAddDelEntryReply, error)
 	NshAddDelMap(ctx context.Context, in *NshAddDelMap) (*NshAddDelMapReply, error)
@@ -33,7 +33,7 @@ func (c *serviceClient) NshAddDelEntry(ctx context.Context, in *NshAddDelEntry)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NshAddDelMap(ctx context.Context, in *NshAddDelMap) (*NshAddDelMapReply, error) {
@@ -42,7 +42,7 @@ func (c *serviceClient) NshAddDelMap(ctx context.Context, in *NshAddDelMap) (*Ns
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NshEntryDump(ctx context.Context, in *NshEntryDump) (RPCService_NshEntryDumpClient, error) {
diff --git a/binapi/nsim/nsim.ba.go b/binapi/nsim/nsim.ba.go
index fb540ac..1f23c79 100644
--- a/binapi/nsim/nsim.ba.go
+++ b/binapi/nsim/nsim.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/nsim.api.json
 
 // Package nsim contains generated bindings for API file nsim.api.
diff --git a/binapi/nsim/nsim_rest.ba.go b/binapi/nsim/nsim_rest.ba.go
deleted file mode 100644
index ba53f21..0000000
--- a/binapi/nsim/nsim_rest.ba.go
+++ /dev/null
@@ -1,83 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package nsim
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/nsim_configure", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NsimConfigure)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NsimConfigure(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nsim_cross_connect_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NsimCrossConnectEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NsimCrossConnectEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/nsim_output_feature_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(NsimOutputFeatureEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.NsimOutputFeatureEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/nsim/nsim_rpc.ba.go b/binapi/nsim/nsim_rpc.ba.go
index 863f945..d46b1ef 100644
--- a/binapi/nsim/nsim_rpc.ba.go
+++ b/binapi/nsim/nsim_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  nsim.
+// RPCService defines RPC service nsim.
 type RPCService interface {
 	NsimConfigure(ctx context.Context, in *NsimConfigure) (*NsimConfigureReply, error)
 	NsimCrossConnectEnableDisable(ctx context.Context, in *NsimCrossConnectEnableDisable) (*NsimCrossConnectEnableDisableReply, error)
@@ -29,7 +29,7 @@ func (c *serviceClient) NsimConfigure(ctx context.Context, in *NsimConfigure) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NsimCrossConnectEnableDisable(ctx context.Context, in *NsimCrossConnectEnableDisable) (*NsimCrossConnectEnableDisableReply, error) {
@@ -38,7 +38,7 @@ func (c *serviceClient) NsimCrossConnectEnableDisable(ctx context.Context, in *N
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) NsimOutputFeatureEnableDisable(ctx context.Context, in *NsimOutputFeatureEnableDisable) (*NsimOutputFeatureEnableDisableReply, error) {
@@ -47,5 +47,5 @@ func (c *serviceClient) NsimOutputFeatureEnableDisable(ctx context.Context, in *
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/oddbuf/oddbuf.ba.go b/binapi/oddbuf/oddbuf.ba.go
index c6f3e21..bfea709 100644
--- a/binapi/oddbuf/oddbuf.ba.go
+++ b/binapi/oddbuf/oddbuf.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/oddbuf.api.json
 
 // Package oddbuf contains generated bindings for API file oddbuf.api.
diff --git a/binapi/oddbuf/oddbuf_rest.ba.go b/binapi/oddbuf/oddbuf_rest.ba.go
deleted file mode 100644
index b50418c..0000000
--- a/binapi/oddbuf/oddbuf_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package oddbuf
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/oddbuf_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OddbufEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OddbufEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/oddbuf/oddbuf_rpc.ba.go b/binapi/oddbuf/oddbuf_rpc.ba.go
index 93ccf3b..f7c0164 100644
--- a/binapi/oddbuf/oddbuf_rpc.ba.go
+++ b/binapi/oddbuf/oddbuf_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  oddbuf.
+// RPCService defines RPC service oddbuf.
 type RPCService interface {
 	OddbufEnableDisable(ctx context.Context, in *OddbufEnableDisable) (*OddbufEnableDisableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) OddbufEnableDisable(ctx context.Context, in *OddbufEnabl
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/one/one.ba.go b/binapi/one/one.ba.go
index 01a5597..dc9c6ea 100644
--- a/binapi/one/one.ba.go
+++ b/binapi/one/one.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/one.api.json
 
 // Package one contains generated bindings for API file one.api.
diff --git a/binapi/one/one_rest.ba.go b/binapi/one/one_rest.ba.go
deleted file mode 100644
index 2c3caca..0000000
--- a/binapi/one/one_rest.ba.go
+++ /dev/null
@@ -1,910 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package one
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/one_add_del_adjacency", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAddDelAdjacency)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAddDelAdjacency(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_add_del_l2_arp_entry", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAddDelL2ArpEntry)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAddDelL2ArpEntry(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_add_del_local_eid", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAddDelLocalEid)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAddDelLocalEid(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_add_del_locator", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAddDelLocator)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAddDelLocator(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_add_del_locator_set", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAddDelLocatorSet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAddDelLocatorSet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_add_del_map_request_itr_rlocs", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAddDelMapRequestItrRlocs)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAddDelMapRequestItrRlocs(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_add_del_map_resolver", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAddDelMapResolver)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAddDelMapResolver(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_add_del_map_server", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAddDelMapServer)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAddDelMapServer(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_add_del_ndp_entry", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAddDelNdpEntry)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAddDelNdpEntry(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_add_del_remote_mapping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAddDelRemoteMapping)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAddDelRemoteMapping(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_adjacencies_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneAdjacenciesGet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneAdjacenciesGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_eid_table_add_del_map", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneEidTableAddDelMap)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneEidTableAddDelMap(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_enable_disable_petr_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneEnableDisablePetrMode)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneEnableDisablePetrMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_enable_disable_pitr_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneEnableDisablePitrMode)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneEnableDisablePitrMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_enable_disable_xtr_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneEnableDisableXtrMode)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneEnableDisableXtrMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_get_map_request_itr_rlocs", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneGetMapRequestItrRlocs)
-		reply, err := rpc.OneGetMapRequestItrRlocs(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_get_transport_protocol", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneGetTransportProtocol)
-		reply, err := rpc.OneGetTransportProtocol(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_l2_arp_bd_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneL2ArpBdGet)
-		reply, err := rpc.OneL2ArpBdGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_l2_arp_entries_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneL2ArpEntriesGet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneL2ArpEntriesGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_map_register_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneMapRegisterEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneMapRegisterEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_map_register_fallback_threshold", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneMapRegisterFallbackThreshold)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneMapRegisterFallbackThreshold(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_map_register_set_ttl", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneMapRegisterSetTTL)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneMapRegisterSetTTL(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_map_request_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneMapRequestMode)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneMapRequestMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_ndp_bd_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneNdpBdGet)
-		reply, err := rpc.OneNdpBdGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_ndp_entries_get", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneNdpEntriesGet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneNdpEntriesGet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_nsh_set_locator_set", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneNshSetLocatorSet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneNshSetLocatorSet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_pitr_set_locator_set", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OnePitrSetLocatorSet)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OnePitrSetLocatorSet(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_rloc_probe_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneRlocProbeEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneRlocProbeEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_set_transport_protocol", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneSetTransportProtocol)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneSetTransportProtocol(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_show_petr_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneShowPetrMode)
-		reply, err := rpc.OneShowPetrMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_show_pitr_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneShowPitrMode)
-		reply, err := rpc.OneShowPitrMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_show_xtr_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneShowXtrMode)
-		reply, err := rpc.OneShowXtrMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_stats_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneStatsEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneStatsEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_stats_flush", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneStatsFlush)
-		reply, err := rpc.OneStatsFlush(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/one_use_petr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(OneUsePetr)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.OneUsePetr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_one_map_register_fallback_threshold", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowOneMapRegisterFallbackThreshold)
-		reply, err := rpc.ShowOneMapRegisterFallbackThreshold(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_one_map_register_state", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowOneMapRegisterState)
-		reply, err := rpc.ShowOneMapRegisterState(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_one_map_register_ttl", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowOneMapRegisterTTL)
-		reply, err := rpc.ShowOneMapRegisterTTL(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_one_map_request_mode", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowOneMapRequestMode)
-		reply, err := rpc.ShowOneMapRequestMode(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_one_nsh_mapping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowOneNshMapping)
-		reply, err := rpc.ShowOneNshMapping(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_one_pitr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowOnePitr)
-		reply, err := rpc.ShowOnePitr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_one_rloc_probe_state", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowOneRlocProbeState)
-		reply, err := rpc.ShowOneRlocProbeState(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_one_stats_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowOneStatsEnableDisable)
-		reply, err := rpc.ShowOneStatsEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_one_status", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowOneStatus)
-		reply, err := rpc.ShowOneStatus(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_one_use_petr", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowOneUsePetr)
-		reply, err := rpc.ShowOneUsePetr(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/one/one_rpc.ba.go b/binapi/one/one_rpc.ba.go
index b870ba1..2ef9c5e 100644
--- a/binapi/one/one_rpc.ba.go
+++ b/binapi/one/one_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  one.
+// RPCService defines RPC service one.
 type RPCService interface {
 	OneAddDelAdjacency(ctx context.Context, in *OneAddDelAdjacency) (*OneAddDelAdjacencyReply, error)
 	OneAddDelL2ArpEntry(ctx context.Context, in *OneAddDelL2ArpEntry) (*OneAddDelL2ArpEntryReply, error)
@@ -83,7 +83,7 @@ func (c *serviceClient) OneAddDelAdjacency(ctx context.Context, in *OneAddDelAdj
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneAddDelL2ArpEntry(ctx context.Context, in *OneAddDelL2ArpEntry) (*OneAddDelL2ArpEntryReply, error) {
@@ -92,7 +92,7 @@ func (c *serviceClient) OneAddDelL2ArpEntry(ctx context.Context, in *OneAddDelL2
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneAddDelLocalEid(ctx context.Context, in *OneAddDelLocalEid) (*OneAddDelLocalEidReply, error) {
@@ -101,7 +101,7 @@ func (c *serviceClient) OneAddDelLocalEid(ctx context.Context, in *OneAddDelLoca
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneAddDelLocator(ctx context.Context, in *OneAddDelLocator) (*OneAddDelLocatorReply, error) {
@@ -110,7 +110,7 @@ func (c *serviceClient) OneAddDelLocator(ctx context.Context, in *OneAddDelLocat
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneAddDelLocatorSet(ctx context.Context, in *OneAddDelLocatorSet) (*OneAddDelLocatorSetReply, error) {
@@ -119,7 +119,7 @@ func (c *serviceClient) OneAddDelLocatorSet(ctx context.Context, in *OneAddDelLo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneAddDelMapRequestItrRlocs(ctx context.Context, in *OneAddDelMapRequestItrRlocs) (*OneAddDelMapRequestItrRlocsReply, error) {
@@ -128,7 +128,7 @@ func (c *serviceClient) OneAddDelMapRequestItrRlocs(ctx context.Context, in *One
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneAddDelMapResolver(ctx context.Context, in *OneAddDelMapResolver) (*OneAddDelMapResolverReply, error) {
@@ -137,7 +137,7 @@ func (c *serviceClient) OneAddDelMapResolver(ctx context.Context, in *OneAddDelM
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneAddDelMapServer(ctx context.Context, in *OneAddDelMapServer) (*OneAddDelMapServerReply, error) {
@@ -146,7 +146,7 @@ func (c *serviceClient) OneAddDelMapServer(ctx context.Context, in *OneAddDelMap
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneAddDelNdpEntry(ctx context.Context, in *OneAddDelNdpEntry) (*OneAddDelNdpEntryReply, error) {
@@ -155,7 +155,7 @@ func (c *serviceClient) OneAddDelNdpEntry(ctx context.Context, in *OneAddDelNdpE
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneAddDelRemoteMapping(ctx context.Context, in *OneAddDelRemoteMapping) (*OneAddDelRemoteMappingReply, error) {
@@ -164,7 +164,7 @@ func (c *serviceClient) OneAddDelRemoteMapping(ctx context.Context, in *OneAddDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneAdjacenciesGet(ctx context.Context, in *OneAdjacenciesGet) (*OneAdjacenciesGetReply, error) {
@@ -173,7 +173,7 @@ func (c *serviceClient) OneAdjacenciesGet(ctx context.Context, in *OneAdjacencie
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneEidTableAddDelMap(ctx context.Context, in *OneEidTableAddDelMap) (*OneEidTableAddDelMapReply, error) {
@@ -182,7 +182,7 @@ func (c *serviceClient) OneEidTableAddDelMap(ctx context.Context, in *OneEidTabl
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneEidTableDump(ctx context.Context, in *OneEidTableDump) (RPCService_OneEidTableDumpClient, error) {
@@ -308,7 +308,7 @@ func (c *serviceClient) OneEnableDisable(ctx context.Context, in *OneEnableDisab
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneEnableDisablePetrMode(ctx context.Context, in *OneEnableDisablePetrMode) (*OneEnableDisablePetrModeReply, error) {
@@ -317,7 +317,7 @@ func (c *serviceClient) OneEnableDisablePetrMode(ctx context.Context, in *OneEna
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneEnableDisablePitrMode(ctx context.Context, in *OneEnableDisablePitrMode) (*OneEnableDisablePitrModeReply, error) {
@@ -326,7 +326,7 @@ func (c *serviceClient) OneEnableDisablePitrMode(ctx context.Context, in *OneEna
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneEnableDisableXtrMode(ctx context.Context, in *OneEnableDisableXtrMode) (*OneEnableDisableXtrModeReply, error) {
@@ -335,7 +335,7 @@ func (c *serviceClient) OneEnableDisableXtrMode(ctx context.Context, in *OneEnab
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneGetMapRequestItrRlocs(ctx context.Context, in *OneGetMapRequestItrRlocs) (*OneGetMapRequestItrRlocsReply, error) {
@@ -344,7 +344,7 @@ func (c *serviceClient) OneGetMapRequestItrRlocs(ctx context.Context, in *OneGet
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneGetTransportProtocol(ctx context.Context, in *OneGetTransportProtocol) (*OneGetTransportProtocolReply, error) {
@@ -353,7 +353,7 @@ func (c *serviceClient) OneGetTransportProtocol(ctx context.Context, in *OneGetT
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneL2ArpBdGet(ctx context.Context, in *OneL2ArpBdGet) (*OneL2ArpBdGetReply, error) {
@@ -362,7 +362,7 @@ func (c *serviceClient) OneL2ArpBdGet(ctx context.Context, in *OneL2ArpBdGet) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneL2ArpEntriesGet(ctx context.Context, in *OneL2ArpEntriesGet) (*OneL2ArpEntriesGetReply, error) {
@@ -371,7 +371,7 @@ func (c *serviceClient) OneL2ArpEntriesGet(ctx context.Context, in *OneL2ArpEntr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneLocatorDump(ctx context.Context, in *OneLocatorDump) (RPCService_OneLocatorDumpClient, error) {
@@ -458,7 +458,7 @@ func (c *serviceClient) OneMapRegisterEnableDisable(ctx context.Context, in *One
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneMapRegisterFallbackThreshold(ctx context.Context, in *OneMapRegisterFallbackThreshold) (*OneMapRegisterFallbackThresholdReply, error) {
@@ -467,7 +467,7 @@ func (c *serviceClient) OneMapRegisterFallbackThreshold(ctx context.Context, in
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneMapRegisterSetTTL(ctx context.Context, in *OneMapRegisterSetTTL) (*OneMapRegisterSetTTLReply, error) {
@@ -476,7 +476,7 @@ func (c *serviceClient) OneMapRegisterSetTTL(ctx context.Context, in *OneMapRegi
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneMapRequestMode(ctx context.Context, in *OneMapRequestMode) (*OneMapRequestModeReply, error) {
@@ -485,7 +485,7 @@ func (c *serviceClient) OneMapRequestMode(ctx context.Context, in *OneMapRequest
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneMapResolverDump(ctx context.Context, in *OneMapResolverDump) (RPCService_OneMapResolverDumpClient, error) {
@@ -572,7 +572,7 @@ func (c *serviceClient) OneNdpBdGet(ctx context.Context, in *OneNdpBdGet) (*OneN
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneNdpEntriesGet(ctx context.Context, in *OneNdpEntriesGet) (*OneNdpEntriesGetReply, error) {
@@ -581,7 +581,7 @@ func (c *serviceClient) OneNdpEntriesGet(ctx context.Context, in *OneNdpEntriesG
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneNshSetLocatorSet(ctx context.Context, in *OneNshSetLocatorSet) (*OneNshSetLocatorSetReply, error) {
@@ -590,7 +590,7 @@ func (c *serviceClient) OneNshSetLocatorSet(ctx context.Context, in *OneNshSetLo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OnePitrSetLocatorSet(ctx context.Context, in *OnePitrSetLocatorSet) (*OnePitrSetLocatorSetReply, error) {
@@ -599,7 +599,7 @@ func (c *serviceClient) OnePitrSetLocatorSet(ctx context.Context, in *OnePitrSet
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneRlocProbeEnableDisable(ctx context.Context, in *OneRlocProbeEnableDisable) (*OneRlocProbeEnableDisableReply, error) {
@@ -608,7 +608,7 @@ func (c *serviceClient) OneRlocProbeEnableDisable(ctx context.Context, in *OneRl
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneSetTransportProtocol(ctx context.Context, in *OneSetTransportProtocol) (*OneSetTransportProtocolReply, error) {
@@ -617,7 +617,7 @@ func (c *serviceClient) OneSetTransportProtocol(ctx context.Context, in *OneSetT
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneShowPetrMode(ctx context.Context, in *OneShowPetrMode) (*OneShowPetrModeReply, error) {
@@ -626,7 +626,7 @@ func (c *serviceClient) OneShowPetrMode(ctx context.Context, in *OneShowPetrMode
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneShowPitrMode(ctx context.Context, in *OneShowPitrMode) (*OneShowPitrModeReply, error) {
@@ -635,7 +635,7 @@ func (c *serviceClient) OneShowPitrMode(ctx context.Context, in *OneShowPitrMode
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneShowXtrMode(ctx context.Context, in *OneShowXtrMode) (*OneShowXtrModeReply, error) {
@@ -644,7 +644,7 @@ func (c *serviceClient) OneShowXtrMode(ctx context.Context, in *OneShowXtrMode)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneStatsDump(ctx context.Context, in *OneStatsDump) (RPCService_OneStatsDumpClient, error) {
@@ -692,7 +692,7 @@ func (c *serviceClient) OneStatsEnableDisable(ctx context.Context, in *OneStatsE
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneStatsFlush(ctx context.Context, in *OneStatsFlush) (*OneStatsFlushReply, error) {
@@ -701,7 +701,7 @@ func (c *serviceClient) OneStatsFlush(ctx context.Context, in *OneStatsFlush) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) OneUsePetr(ctx context.Context, in *OneUsePetr) (*OneUsePetrReply, error) {
@@ -710,7 +710,7 @@ func (c *serviceClient) OneUsePetr(ctx context.Context, in *OneUsePetr) (*OneUse
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowOneMapRegisterFallbackThreshold(ctx context.Context, in *ShowOneMapRegisterFallbackThreshold) (*ShowOneMapRegisterFallbackThresholdReply, error) {
@@ -719,7 +719,7 @@ func (c *serviceClient) ShowOneMapRegisterFallbackThreshold(ctx context.Context,
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowOneMapRegisterState(ctx context.Context, in *ShowOneMapRegisterState) (*ShowOneMapRegisterStateReply, error) {
@@ -728,7 +728,7 @@ func (c *serviceClient) ShowOneMapRegisterState(ctx context.Context, in *ShowOne
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowOneMapRegisterTTL(ctx context.Context, in *ShowOneMapRegisterTTL) (*ShowOneMapRegisterTTLReply, error) {
@@ -737,7 +737,7 @@ func (c *serviceClient) ShowOneMapRegisterTTL(ctx context.Context, in *ShowOneMa
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowOneMapRequestMode(ctx context.Context, in *ShowOneMapRequestMode) (*ShowOneMapRequestModeReply, error) {
@@ -746,7 +746,7 @@ func (c *serviceClient) ShowOneMapRequestMode(ctx context.Context, in *ShowOneMa
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowOneNshMapping(ctx context.Context, in *ShowOneNshMapping) (*ShowOneNshMappingReply, error) {
@@ -755,7 +755,7 @@ func (c *serviceClient) ShowOneNshMapping(ctx context.Context, in *ShowOneNshMap
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowOnePitr(ctx context.Context, in *ShowOnePitr) (*ShowOnePitrReply, error) {
@@ -764,7 +764,7 @@ func (c *serviceClient) ShowOnePitr(ctx context.Context, in *ShowOnePitr) (*Show
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowOneRlocProbeState(ctx context.Context, in *ShowOneRlocProbeState) (*ShowOneRlocProbeStateReply, error) {
@@ -773,7 +773,7 @@ func (c *serviceClient) ShowOneRlocProbeState(ctx context.Context, in *ShowOneRl
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowOneStatsEnableDisable(ctx context.Context, in *ShowOneStatsEnableDisable) (*ShowOneStatsEnableDisableReply, error) {
@@ -782,7 +782,7 @@ func (c *serviceClient) ShowOneStatsEnableDisable(ctx context.Context, in *ShowO
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowOneStatus(ctx context.Context, in *ShowOneStatus) (*ShowOneStatusReply, error) {
@@ -791,7 +791,7 @@ func (c *serviceClient) ShowOneStatus(ctx context.Context, in *ShowOneStatus) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowOneUsePetr(ctx context.Context, in *ShowOneUsePetr) (*ShowOneUsePetrReply, error) {
@@ -800,5 +800,5 @@ func (c *serviceClient) ShowOneUsePetr(ctx context.Context, in *ShowOneUsePetr)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/p2p_ethernet/p2p_ethernet.ba.go b/binapi/p2p_ethernet/p2p_ethernet.ba.go
index 2f76041..d9f9a9c 100644
--- a/binapi/p2p_ethernet/p2p_ethernet.ba.go
+++ b/binapi/p2p_ethernet/p2p_ethernet.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/p2p_ethernet.api.json
 
 // Package p2p_ethernet contains generated bindings for API file p2p_ethernet.api.
diff --git a/binapi/p2p_ethernet/p2p_ethernet_rest.ba.go b/binapi/p2p_ethernet/p2p_ethernet_rest.ba.go
deleted file mode 100644
index e154276..0000000
--- a/binapi/p2p_ethernet/p2p_ethernet_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package p2p_ethernet
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/p2p_ethernet_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(P2pEthernetAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.P2pEthernetAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/p2p_ethernet_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(P2pEthernetDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.P2pEthernetDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/p2p_ethernet/p2p_ethernet_rpc.ba.go b/binapi/p2p_ethernet/p2p_ethernet_rpc.ba.go
index 98cc2e3..c96d6a5 100644
--- a/binapi/p2p_ethernet/p2p_ethernet_rpc.ba.go
+++ b/binapi/p2p_ethernet/p2p_ethernet_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  p2p_ethernet.
+// RPCService defines RPC service p2p_ethernet.
 type RPCService interface {
 	P2pEthernetAdd(ctx context.Context, in *P2pEthernetAdd) (*P2pEthernetAddReply, error)
 	P2pEthernetDel(ctx context.Context, in *P2pEthernetDel) (*P2pEthernetDelReply, error)
@@ -28,7 +28,7 @@ func (c *serviceClient) P2pEthernetAdd(ctx context.Context, in *P2pEthernetAdd)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) P2pEthernetDel(ctx context.Context, in *P2pEthernetDel) (*P2pEthernetDelReply, error) {
@@ -37,5 +37,5 @@ func (c *serviceClient) P2pEthernetDel(ctx context.Context, in *P2pEthernetDel)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/pci_types/pci_types.ba.go b/binapi/pci_types/pci_types.ba.go
index 7b0d00c..fe12ece 100644
--- a/binapi/pci_types/pci_types.ba.go
+++ b/binapi/pci_types/pci_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/pci_types.api.json
 
 // Package pci_types contains generated bindings for API file pci_types.api.
diff --git a/binapi/pg/pg.ba.go b/binapi/pg/pg.ba.go
index 9a522c2..5fc4efb 100644
--- a/binapi/pg/pg.ba.go
+++ b/binapi/pg/pg.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/pg.api.json
 
 // Package pg contains generated bindings for API file pg.api.
diff --git a/binapi/pg/pg_rest.ba.go b/binapi/pg/pg_rest.ba.go
deleted file mode 100644
index 6384ac4..0000000
--- a/binapi/pg/pg_rest.ba.go
+++ /dev/null
@@ -1,83 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package pg
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/pg_capture", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PgCapture)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PgCapture(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/pg_create_interface", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PgCreateInterface)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PgCreateInterface(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/pg_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PgEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PgEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/pg/pg_rpc.ba.go b/binapi/pg/pg_rpc.ba.go
index 28790a8..697f684 100644
--- a/binapi/pg/pg_rpc.ba.go
+++ b/binapi/pg/pg_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  pg.
+// RPCService defines RPC service pg.
 type RPCService interface {
 	PgCapture(ctx context.Context, in *PgCapture) (*PgCaptureReply, error)
 	PgCreateInterface(ctx context.Context, in *PgCreateInterface) (*PgCreateInterfaceReply, error)
@@ -29,7 +29,7 @@ func (c *serviceClient) PgCapture(ctx context.Context, in *PgCapture) (*PgCaptur
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PgCreateInterface(ctx context.Context, in *PgCreateInterface) (*PgCreateInterfaceReply, error) {
@@ -38,7 +38,7 @@ func (c *serviceClient) PgCreateInterface(ctx context.Context, in *PgCreateInter
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PgEnableDisable(ctx context.Context, in *PgEnableDisable) (*PgEnableDisableReply, error) {
@@ -47,5 +47,5 @@ func (c *serviceClient) PgEnableDisable(ctx context.Context, in *PgEnableDisable
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/pipe/pipe.ba.go b/binapi/pipe/pipe.ba.go
index 6123059..f50db2a 100644
--- a/binapi/pipe/pipe.ba.go
+++ b/binapi/pipe/pipe.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/pipe.api.json
 
 // Package pipe contains generated bindings for API file pipe.api.
diff --git a/binapi/pipe/pipe_rest.ba.go b/binapi/pipe/pipe_rest.ba.go
deleted file mode 100644
index 8a2b900..0000000
--- a/binapi/pipe/pipe_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package pipe
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/pipe_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PipeCreate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PipeCreate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/pipe_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PipeDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PipeDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/pipe/pipe_rpc.ba.go b/binapi/pipe/pipe_rpc.ba.go
index a084d9f..34fbf54 100644
--- a/binapi/pipe/pipe_rpc.ba.go
+++ b/binapi/pipe/pipe_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  pipe.
+// RPCService defines RPC service pipe.
 type RPCService interface {
 	PipeCreate(ctx context.Context, in *PipeCreate) (*PipeCreateReply, error)
 	PipeDelete(ctx context.Context, in *PipeDelete) (*PipeDeleteReply, error)
@@ -32,7 +32,7 @@ func (c *serviceClient) PipeCreate(ctx context.Context, in *PipeCreate) (*PipeCr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PipeDelete(ctx context.Context, in *PipeDelete) (*PipeDeleteReply, error) {
@@ -41,7 +41,7 @@ func (c *serviceClient) PipeDelete(ctx context.Context, in *PipeDelete) (*PipeDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PipeDump(ctx context.Context, in *PipeDump) (RPCService_PipeDumpClient, error) {
diff --git a/binapi/policer/policer.ba.go b/binapi/policer/policer.ba.go
index 1314dce..525abb8 100644
--- a/binapi/policer/policer.ba.go
+++ b/binapi/policer/policer.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/policer.api.json
 
 // Package policer contains generated bindings for API file policer.api.
diff --git a/binapi/policer/policer_rest.ba.go b/binapi/policer/policer_rest.ba.go
deleted file mode 100644
index e53e42d..0000000
--- a/binapi/policer/policer_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package policer
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/policer_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PolicerAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PolicerAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/policer/policer_rpc.ba.go b/binapi/policer/policer_rpc.ba.go
index 870ba87..85c55ca 100644
--- a/binapi/policer/policer_rpc.ba.go
+++ b/binapi/policer/policer_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  policer.
+// RPCService defines RPC service policer.
 type RPCService interface {
 	PolicerAddDel(ctx context.Context, in *PolicerAddDel) (*PolicerAddDelReply, error)
 	PolicerDump(ctx context.Context, in *PolicerDump) (RPCService_PolicerDumpClient, error)
@@ -31,7 +31,7 @@ func (c *serviceClient) PolicerAddDel(ctx context.Context, in *PolicerAddDel) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PolicerDump(ctx context.Context, in *PolicerDump) (RPCService_PolicerDumpClient, error) {
diff --git a/binapi/policer_types/policer_types.ba.go b/binapi/policer_types/policer_types.ba.go
index bdb259a..24cc191 100644
--- a/binapi/policer_types/policer_types.ba.go
+++ b/binapi/policer_types/policer_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/policer_types.api.json
 
 // Package policer_types contains generated bindings for API file policer_types.api.
diff --git a/binapi/pot/pot.ba.go b/binapi/pot/pot.ba.go
index 2c2d1f4..5edf20f 100644
--- a/binapi/pot/pot.ba.go
+++ b/binapi/pot/pot.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/pot.api.json
 
 // Package pot contains generated bindings for API file pot.api.
diff --git a/binapi/pot/pot_rest.ba.go b/binapi/pot/pot_rest.ba.go
deleted file mode 100644
index 0cf6474..0000000
--- a/binapi/pot/pot_rest.ba.go
+++ /dev/null
@@ -1,83 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package pot
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/pot_profile_activate", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PotProfileActivate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PotProfileActivate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/pot_profile_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PotProfileAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PotProfileAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/pot_profile_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PotProfileDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PotProfileDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/pot/pot_rpc.ba.go b/binapi/pot/pot_rpc.ba.go
index 3b43d50..ea975fd 100644
--- a/binapi/pot/pot_rpc.ba.go
+++ b/binapi/pot/pot_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  pot.
+// RPCService defines RPC service pot.
 type RPCService interface {
 	PotProfileActivate(ctx context.Context, in *PotProfileActivate) (*PotProfileActivateReply, error)
 	PotProfileAdd(ctx context.Context, in *PotProfileAdd) (*PotProfileAddReply, error)
@@ -33,7 +33,7 @@ func (c *serviceClient) PotProfileActivate(ctx context.Context, in *PotProfileAc
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PotProfileAdd(ctx context.Context, in *PotProfileAdd) (*PotProfileAddReply, error) {
@@ -42,7 +42,7 @@ func (c *serviceClient) PotProfileAdd(ctx context.Context, in *PotProfileAdd) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PotProfileDel(ctx context.Context, in *PotProfileDel) (*PotProfileDelReply, error) {
@@ -51,7 +51,7 @@ func (c *serviceClient) PotProfileDel(ctx context.Context, in *PotProfileDel) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PotProfileShowConfigDump(ctx context.Context, in *PotProfileShowConfigDump) (RPCService_PotProfileShowConfigDumpClient, error) {
diff --git a/binapi/pppoe/pppoe.ba.go b/binapi/pppoe/pppoe.ba.go
index e01d3b5..277ee86 100644
--- a/binapi/pppoe/pppoe.ba.go
+++ b/binapi/pppoe/pppoe.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/pppoe.api.json
 
 // Package pppoe contains generated bindings for API file pppoe.api.
diff --git a/binapi/pppoe/pppoe_rest.ba.go b/binapi/pppoe/pppoe_rest.ba.go
deleted file mode 100644
index 6b01227..0000000
--- a/binapi/pppoe/pppoe_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package pppoe
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/pppoe_add_del_session", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PppoeAddDelSession)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PppoeAddDelSession(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/pppoe/pppoe_rpc.ba.go b/binapi/pppoe/pppoe_rpc.ba.go
index 6a21a10..075803f 100644
--- a/binapi/pppoe/pppoe_rpc.ba.go
+++ b/binapi/pppoe/pppoe_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  pppoe.
+// RPCService defines RPC service pppoe.
 type RPCService interface {
 	PppoeAddDelSession(ctx context.Context, in *PppoeAddDelSession) (*PppoeAddDelSessionReply, error)
 	PppoeSessionDump(ctx context.Context, in *PppoeSessionDump) (RPCService_PppoeSessionDumpClient, error)
@@ -31,7 +31,7 @@ func (c *serviceClient) PppoeAddDelSession(ctx context.Context, in *PppoeAddDelS
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PppoeSessionDump(ctx context.Context, in *PppoeSessionDump) (RPCService_PppoeSessionDumpClient, error) {
diff --git a/binapi/punt/punt.ba.go b/binapi/punt/punt.ba.go
index 1a84dbf..158672a 100644
--- a/binapi/punt/punt.ba.go
+++ b/binapi/punt/punt.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/punt.api.json
 
 // Package punt contains generated bindings for API file punt.api.
diff --git a/binapi/punt/punt_rest.ba.go b/binapi/punt/punt_rest.ba.go
deleted file mode 100644
index 5b999b9..0000000
--- a/binapi/punt/punt_rest.ba.go
+++ /dev/null
@@ -1,83 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package punt
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/punt_socket_deregister", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PuntSocketDeregister)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PuntSocketDeregister(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/punt_socket_register", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(PuntSocketRegister)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.PuntSocketRegister(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/set_punt", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SetPunt)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SetPunt(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/punt/punt_rpc.ba.go b/binapi/punt/punt_rpc.ba.go
index 9a058cb..b27fbd4 100644
--- a/binapi/punt/punt_rpc.ba.go
+++ b/binapi/punt/punt_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  punt.
+// RPCService defines RPC service punt.
 type RPCService interface {
 	PuntReasonDump(ctx context.Context, in *PuntReasonDump) (RPCService_PuntReasonDumpClient, error)
 	PuntSocketDeregister(ctx context.Context, in *PuntSocketDeregister) (*PuntSocketDeregisterReply, error)
@@ -73,7 +73,7 @@ func (c *serviceClient) PuntSocketDeregister(ctx context.Context, in *PuntSocket
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) PuntSocketDump(ctx context.Context, in *PuntSocketDump) (RPCService_PuntSocketDumpClient, error) {
@@ -121,7 +121,7 @@ func (c *serviceClient) PuntSocketRegister(ctx context.Context, in *PuntSocketRe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SetPunt(ctx context.Context, in *SetPunt) (*SetPuntReply, error) {
@@ -130,5 +130,5 @@ func (c *serviceClient) SetPunt(ctx context.Context, in *SetPunt) (*SetPuntReply
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/qos/qos.ba.go b/binapi/qos/qos.ba.go
index 285e2c8..27aaf6b 100644
--- a/binapi/qos/qos.ba.go
+++ b/binapi/qos/qos.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/qos.api.json
 
 // Package qos contains generated bindings for API file qos.api.
diff --git a/binapi/qos/qos_rest.ba.go b/binapi/qos/qos_rest.ba.go
deleted file mode 100644
index 2e0e546..0000000
--- a/binapi/qos/qos_rest.ba.go
+++ /dev/null
@@ -1,129 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package qos
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/qos_egress_map_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(QosEgressMapDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.QosEgressMapDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/qos_egress_map_update", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(QosEgressMapUpdate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.QosEgressMapUpdate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/qos_mark_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(QosMarkEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.QosMarkEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/qos_record_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(QosRecordEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.QosRecordEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/qos_store_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(QosStoreEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.QosStoreEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/qos/qos_rpc.ba.go b/binapi/qos/qos_rpc.ba.go
index 50f6427..9ad1b1d 100644
--- a/binapi/qos/qos_rpc.ba.go
+++ b/binapi/qos/qos_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  qos.
+// RPCService defines RPC service qos.
 type RPCService interface {
 	QosEgressMapDelete(ctx context.Context, in *QosEgressMapDelete) (*QosEgressMapDeleteReply, error)
 	QosEgressMapDump(ctx context.Context, in *QosEgressMapDump) (RPCService_QosEgressMapDumpClient, error)
@@ -38,7 +38,7 @@ func (c *serviceClient) QosEgressMapDelete(ctx context.Context, in *QosEgressMap
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) QosEgressMapDump(ctx context.Context, in *QosEgressMapDump) (RPCService_QosEgressMapDumpClient, error) {
@@ -86,7 +86,7 @@ func (c *serviceClient) QosEgressMapUpdate(ctx context.Context, in *QosEgressMap
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) QosMarkDump(ctx context.Context, in *QosMarkDump) (RPCService_QosMarkDumpClient, error) {
@@ -134,7 +134,7 @@ func (c *serviceClient) QosMarkEnableDisable(ctx context.Context, in *QosMarkEna
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) QosRecordDump(ctx context.Context, in *QosRecordDump) (RPCService_QosRecordDumpClient, error) {
@@ -182,7 +182,7 @@ func (c *serviceClient) QosRecordEnableDisable(ctx context.Context, in *QosRecor
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) QosStoreDump(ctx context.Context, in *QosStoreDump) (RPCService_QosStoreDumpClient, error) {
@@ -230,5 +230,5 @@ func (c *serviceClient) QosStoreEnableDisable(ctx context.Context, in *QosStoreE
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/rd_cp/rd_cp.ba.go b/binapi/rd_cp/rd_cp.ba.go
index 8cafa0f..5db01b4 100644
--- a/binapi/rd_cp/rd_cp.ba.go
+++ b/binapi/rd_cp/rd_cp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/rd_cp.api.json
 
 // Package rd_cp contains generated bindings for API file rd_cp.api.
diff --git a/binapi/rd_cp/rd_cp_rest.ba.go b/binapi/rd_cp/rd_cp_rest.ba.go
deleted file mode 100644
index 75e75a0..0000000
--- a/binapi/rd_cp/rd_cp_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package rd_cp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/ip6_nd_address_autoconfig", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(IP6NdAddressAutoconfig)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.IP6NdAddressAutoconfig(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/rd_cp/rd_cp_rpc.ba.go b/binapi/rd_cp/rd_cp_rpc.ba.go
index 5e7e7fe..56b2c18 100644
--- a/binapi/rd_cp/rd_cp_rpc.ba.go
+++ b/binapi/rd_cp/rd_cp_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  rd_cp.
+// RPCService defines RPC service rd_cp.
 type RPCService interface {
 	IP6NdAddressAutoconfig(ctx context.Context, in *IP6NdAddressAutoconfig) (*IP6NdAddressAutoconfigReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) IP6NdAddressAutoconfig(ctx context.Context, in *IP6NdAdd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/rdma/rdma.ba.go b/binapi/rdma/rdma.ba.go
index f331fc6..cb56007 100644
--- a/binapi/rdma/rdma.ba.go
+++ b/binapi/rdma/rdma.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/rdma.api.json
 
 // Package rdma contains generated bindings for API file rdma.api.
diff --git a/binapi/rdma/rdma_rest.ba.go b/binapi/rdma/rdma_rest.ba.go
deleted file mode 100644
index 83346d9..0000000
--- a/binapi/rdma/rdma_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package rdma
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/rdma_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(RdmaCreate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.RdmaCreate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/rdma_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(RdmaDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.RdmaDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/rdma/rdma_rpc.ba.go b/binapi/rdma/rdma_rpc.ba.go
index 7e9f60d..489297d 100644
--- a/binapi/rdma/rdma_rpc.ba.go
+++ b/binapi/rdma/rdma_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  rdma.
+// RPCService defines RPC service rdma.
 type RPCService interface {
 	RdmaCreate(ctx context.Context, in *RdmaCreate) (*RdmaCreateReply, error)
 	RdmaDelete(ctx context.Context, in *RdmaDelete) (*RdmaDeleteReply, error)
@@ -28,7 +28,7 @@ func (c *serviceClient) RdmaCreate(ctx context.Context, in *RdmaCreate) (*RdmaCr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) RdmaDelete(ctx context.Context, in *RdmaDelete) (*RdmaDeleteReply, error) {
@@ -37,5 +37,5 @@ func (c *serviceClient) RdmaDelete(ctx context.Context, in *RdmaDelete) (*RdmaDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/session/session.ba.go b/binapi/session/session.ba.go
index 09a67b0..6bb20b8 100644
--- a/binapi/session/session.ba.go
+++ b/binapi/session/session.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/session.api.json
 
 // Package session contains generated bindings for API file session.api.
diff --git a/binapi/session/session_rest.ba.go b/binapi/session/session_rest.ba.go
deleted file mode 100644
index 1ef2085..0000000
--- a/binapi/session/session_rest.ba.go
+++ /dev/null
@@ -1,235 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package session
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/app_add_cert_key_pair", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AppAddCertKeyPair)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AppAddCertKeyPair(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/app_attach", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AppAttach)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AppAttach(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/app_del_cert_key_pair", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AppDelCertKeyPair)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AppDelCertKeyPair(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/app_namespace_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AppNamespaceAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AppNamespaceAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/app_worker_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AppWorkerAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AppWorkerAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/application_detach", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ApplicationDetach)
-		reply, err := rpc.ApplicationDetach(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/application_tls_cert_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ApplicationTLSCertAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ApplicationTLSCertAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/application_tls_key_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ApplicationTLSKeyAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ApplicationTLSKeyAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/session_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SessionEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SessionEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/session_rule_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SessionRuleAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SessionRuleAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/session/session_rpc.ba.go b/binapi/session/session_rpc.ba.go
index 3868572..58593a0 100644
--- a/binapi/session/session_rpc.ba.go
+++ b/binapi/session/session_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  session.
+// RPCService defines RPC service session.
 type RPCService interface {
 	AppAddCertKeyPair(ctx context.Context, in *AppAddCertKeyPair) (*AppAddCertKeyPairReply, error)
 	AppAttach(ctx context.Context, in *AppAttach) (*AppAttachReply, error)
@@ -40,7 +40,7 @@ func (c *serviceClient) AppAddCertKeyPair(ctx context.Context, in *AppAddCertKey
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) AppAttach(ctx context.Context, in *AppAttach) (*AppAttachReply, error) {
@@ -49,7 +49,7 @@ func (c *serviceClient) AppAttach(ctx context.Context, in *AppAttach) (*AppAttac
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) AppDelCertKeyPair(ctx context.Context, in *AppDelCertKeyPair) (*AppDelCertKeyPairReply, error) {
@@ -58,7 +58,7 @@ func (c *serviceClient) AppDelCertKeyPair(ctx context.Context, in *AppDelCertKey
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) AppNamespaceAddDel(ctx context.Context, in *AppNamespaceAddDel) (*AppNamespaceAddDelReply, error) {
@@ -67,7 +67,7 @@ func (c *serviceClient) AppNamespaceAddDel(ctx context.Context, in *AppNamespace
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) AppWorkerAddDel(ctx context.Context, in *AppWorkerAddDel) (*AppWorkerAddDelReply, error) {
@@ -76,7 +76,7 @@ func (c *serviceClient) AppWorkerAddDel(ctx context.Context, in *AppWorkerAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ApplicationDetach(ctx context.Context, in *ApplicationDetach) (*ApplicationDetachReply, error) {
@@ -85,7 +85,7 @@ func (c *serviceClient) ApplicationDetach(ctx context.Context, in *ApplicationDe
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ApplicationTLSCertAdd(ctx context.Context, in *ApplicationTLSCertAdd) (*ApplicationTLSCertAddReply, error) {
@@ -94,7 +94,7 @@ func (c *serviceClient) ApplicationTLSCertAdd(ctx context.Context, in *Applicati
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ApplicationTLSKeyAdd(ctx context.Context, in *ApplicationTLSKeyAdd) (*ApplicationTLSKeyAddReply, error) {
@@ -103,7 +103,7 @@ func (c *serviceClient) ApplicationTLSKeyAdd(ctx context.Context, in *Applicatio
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SessionEnableDisable(ctx context.Context, in *SessionEnableDisable) (*SessionEnableDisableReply, error) {
@@ -112,7 +112,7 @@ func (c *serviceClient) SessionEnableDisable(ctx context.Context, in *SessionEna
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SessionRuleAddDel(ctx context.Context, in *SessionRuleAddDel) (*SessionRuleAddDelReply, error) {
@@ -121,7 +121,7 @@ func (c *serviceClient) SessionRuleAddDel(ctx context.Context, in *SessionRuleAd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SessionRulesDump(ctx context.Context, in *SessionRulesDump) (RPCService_SessionRulesDumpClient, error) {
diff --git a/binapi/span/span.ba.go b/binapi/span/span.ba.go
index 74855b1..5cc7fe2 100644
--- a/binapi/span/span.ba.go
+++ b/binapi/span/span.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/span.api.json
 
 // Package span contains generated bindings for API file span.api.
diff --git a/binapi/span/span_rest.ba.go b/binapi/span/span_rest.ba.go
deleted file mode 100644
index 0c2d959..0000000
--- a/binapi/span/span_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package span
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/sw_interface_span_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSpanEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSpanEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/span/span_rpc.ba.go b/binapi/span/span_rpc.ba.go
index f9f9538..1452be8 100644
--- a/binapi/span/span_rpc.ba.go
+++ b/binapi/span/span_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  span.
+// RPCService defines RPC service span.
 type RPCService interface {
 	SwInterfaceSpanDump(ctx context.Context, in *SwInterfaceSpanDump) (RPCService_SwInterfaceSpanDumpClient, error)
 	SwInterfaceSpanEnableDisable(ctx context.Context, in *SwInterfaceSpanEnableDisable) (*SwInterfaceSpanEnableDisableReply, error)
@@ -70,5 +70,5 @@ func (c *serviceClient) SwInterfaceSpanEnableDisable(ctx context.Context, in *Sw
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/sr/sr.ba.go b/binapi/sr/sr.ba.go
index 2b98b8a..4b883d2 100644
--- a/binapi/sr/sr.ba.go
+++ b/binapi/sr/sr.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/sr.api.json
 
 // Package sr contains generated bindings for API file sr.api.
diff --git a/binapi/sr/sr_rest.ba.go b/binapi/sr/sr_rest.ba.go
deleted file mode 100644
index 0d3acfc..0000000
--- a/binapi/sr/sr_rest.ba.go
+++ /dev/null
@@ -1,175 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package sr
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/sr_localsid_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrLocalsidAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrLocalsidAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sr_policy_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrPolicyAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrPolicyAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sr_policy_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrPolicyDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrPolicyDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sr_policy_mod", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrPolicyMod)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrPolicyMod(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sr_set_encap_hop_limit", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrSetEncapHopLimit)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrSetEncapHopLimit(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sr_set_encap_source", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrSetEncapSource)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrSetEncapSource(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sr_steering_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrSteeringAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrSteeringAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/sr/sr_rpc.ba.go b/binapi/sr/sr_rpc.ba.go
index 450ced9..7bbfff1 100644
--- a/binapi/sr/sr_rpc.ba.go
+++ b/binapi/sr/sr_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  sr.
+// RPCService defines RPC service sr.
 type RPCService interface {
 	SrLocalsidAddDel(ctx context.Context, in *SrLocalsidAddDel) (*SrLocalsidAddDelReply, error)
 	SrLocalsidsDump(ctx context.Context, in *SrLocalsidsDump) (RPCService_SrLocalsidsDumpClient, error)
@@ -39,7 +39,7 @@ func (c *serviceClient) SrLocalsidAddDel(ctx context.Context, in *SrLocalsidAddD
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrLocalsidsDump(ctx context.Context, in *SrLocalsidsDump) (RPCService_SrLocalsidsDumpClient, error) {
@@ -126,7 +126,7 @@ func (c *serviceClient) SrPolicyAdd(ctx context.Context, in *SrPolicyAdd) (*SrPo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrPolicyDel(ctx context.Context, in *SrPolicyDel) (*SrPolicyDelReply, error) {
@@ -135,7 +135,7 @@ func (c *serviceClient) SrPolicyDel(ctx context.Context, in *SrPolicyDel) (*SrPo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrPolicyMod(ctx context.Context, in *SrPolicyMod) (*SrPolicyModReply, error) {
@@ -144,7 +144,7 @@ func (c *serviceClient) SrPolicyMod(ctx context.Context, in *SrPolicyMod) (*SrPo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrSetEncapHopLimit(ctx context.Context, in *SrSetEncapHopLimit) (*SrSetEncapHopLimitReply, error) {
@@ -153,7 +153,7 @@ func (c *serviceClient) SrSetEncapHopLimit(ctx context.Context, in *SrSetEncapHo
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrSetEncapSource(ctx context.Context, in *SrSetEncapSource) (*SrSetEncapSourceReply, error) {
@@ -162,7 +162,7 @@ func (c *serviceClient) SrSetEncapSource(ctx context.Context, in *SrSetEncapSour
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrSteeringAddDel(ctx context.Context, in *SrSteeringAddDel) (*SrSteeringAddDelReply, error) {
@@ -171,7 +171,7 @@ func (c *serviceClient) SrSteeringAddDel(ctx context.Context, in *SrSteeringAddD
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrSteeringPolDump(ctx context.Context, in *SrSteeringPolDump) (RPCService_SrSteeringPolDumpClient, error) {
diff --git a/binapi/sr_mpls/sr_mpls.ba.go b/binapi/sr_mpls/sr_mpls.ba.go
index e6bd9f0..62ef1a6 100644
--- a/binapi/sr_mpls/sr_mpls.ba.go
+++ b/binapi/sr_mpls/sr_mpls.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/sr_mpls.api.json
 
 // Package sr_mpls contains generated bindings for API file sr_mpls.api.
diff --git a/binapi/sr_mpls/sr_mpls_rest.ba.go b/binapi/sr_mpls/sr_mpls_rest.ba.go
deleted file mode 100644
index 85edbf0..0000000
--- a/binapi/sr_mpls/sr_mpls_rest.ba.go
+++ /dev/null
@@ -1,129 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package sr_mpls
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/sr_mpls_policy_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrMplsPolicyAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrMplsPolicyAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sr_mpls_policy_assign_endpoint_color", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrMplsPolicyAssignEndpointColor)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrMplsPolicyAssignEndpointColor(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sr_mpls_policy_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrMplsPolicyDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrMplsPolicyDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sr_mpls_policy_mod", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrMplsPolicyMod)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrMplsPolicyMod(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/sr_mpls_steering_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SrMplsSteeringAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SrMplsSteeringAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/sr_mpls/sr_mpls_rpc.ba.go b/binapi/sr_mpls/sr_mpls_rpc.ba.go
index ec0f46d..556d32e 100644
--- a/binapi/sr_mpls/sr_mpls_rpc.ba.go
+++ b/binapi/sr_mpls/sr_mpls_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  sr_mpls.
+// RPCService defines RPC service sr_mpls.
 type RPCService interface {
 	SrMplsPolicyAdd(ctx context.Context, in *SrMplsPolicyAdd) (*SrMplsPolicyAddReply, error)
 	SrMplsPolicyAssignEndpointColor(ctx context.Context, in *SrMplsPolicyAssignEndpointColor) (*SrMplsPolicyAssignEndpointColorReply, error)
@@ -31,7 +31,7 @@ func (c *serviceClient) SrMplsPolicyAdd(ctx context.Context, in *SrMplsPolicyAdd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrMplsPolicyAssignEndpointColor(ctx context.Context, in *SrMplsPolicyAssignEndpointColor) (*SrMplsPolicyAssignEndpointColorReply, error) {
@@ -40,7 +40,7 @@ func (c *serviceClient) SrMplsPolicyAssignEndpointColor(ctx context.Context, in
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrMplsPolicyDel(ctx context.Context, in *SrMplsPolicyDel) (*SrMplsPolicyDelReply, error) {
@@ -49,7 +49,7 @@ func (c *serviceClient) SrMplsPolicyDel(ctx context.Context, in *SrMplsPolicyDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrMplsPolicyMod(ctx context.Context, in *SrMplsPolicyMod) (*SrMplsPolicyModReply, error) {
@@ -58,7 +58,7 @@ func (c *serviceClient) SrMplsPolicyMod(ctx context.Context, in *SrMplsPolicyMod
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SrMplsSteeringAddDel(ctx context.Context, in *SrMplsSteeringAddDel) (*SrMplsSteeringAddDelReply, error) {
@@ -67,5 +67,5 @@ func (c *serviceClient) SrMplsSteeringAddDel(ctx context.Context, in *SrMplsStee
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/sr_types/sr_types.ba.go b/binapi/sr_types/sr_types.ba.go
index 7a2007e..1b3ee75 100644
--- a/binapi/sr_types/sr_types.ba.go
+++ b/binapi/sr_types/sr_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/sr_types.api.json
 
 // Package sr_types contains generated bindings for API file sr_types.api.
diff --git a/binapi/stn/stn.ba.go b/binapi/stn/stn.ba.go
index b44adf5..dbdf0ca 100644
--- a/binapi/stn/stn.ba.go
+++ b/binapi/stn/stn.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/stn.api.json
 
 // Package stn contains generated bindings for API file stn.api.
diff --git a/binapi/stn/stn_rest.ba.go b/binapi/stn/stn_rest.ba.go
deleted file mode 100644
index 826aee9..0000000
--- a/binapi/stn/stn_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package stn
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/stn_add_del_rule", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(StnAddDelRule)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.StnAddDelRule(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/stn/stn_rpc.ba.go b/binapi/stn/stn_rpc.ba.go
index 4cc7087..c3dacf8 100644
--- a/binapi/stn/stn_rpc.ba.go
+++ b/binapi/stn/stn_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  stn.
+// RPCService defines RPC service stn.
 type RPCService interface {
 	StnAddDelRule(ctx context.Context, in *StnAddDelRule) (*StnAddDelRuleReply, error)
 	StnRulesDump(ctx context.Context, in *StnRulesDump) (RPCService_StnRulesDumpClient, error)
@@ -31,7 +31,7 @@ func (c *serviceClient) StnAddDelRule(ctx context.Context, in *StnAddDelRule) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) StnRulesDump(ctx context.Context, in *StnRulesDump) (RPCService_StnRulesDumpClient, error) {
diff --git a/binapi/svs/svs.ba.go b/binapi/svs/svs.ba.go
index 911e936..1f65a76 100644
--- a/binapi/svs/svs.ba.go
+++ b/binapi/svs/svs.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/svs.api.json
 
 // Package svs contains generated bindings for API file svs.api.
diff --git a/binapi/svs/svs_rest.ba.go b/binapi/svs/svs_rest.ba.go
deleted file mode 100644
index 4293223..0000000
--- a/binapi/svs/svs_rest.ba.go
+++ /dev/null
@@ -1,97 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package svs
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/svs_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SvsEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SvsEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/svs_plugin_get_version", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SvsPluginGetVersion)
-		reply, err := rpc.SvsPluginGetVersion(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/svs_route_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SvsRouteAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SvsRouteAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/svs_table_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SvsTableAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SvsTableAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/svs/svs_rpc.ba.go b/binapi/svs/svs_rpc.ba.go
index 3de2a03..4d344a1 100644
--- a/binapi/svs/svs_rpc.ba.go
+++ b/binapi/svs/svs_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  svs.
+// RPCService defines RPC service svs.
 type RPCService interface {
 	SvsDump(ctx context.Context, in *SvsDump) (RPCService_SvsDumpClient, error)
 	SvsEnableDisable(ctx context.Context, in *SvsEnableDisable) (*SvsEnableDisableReply, error)
@@ -73,7 +73,7 @@ func (c *serviceClient) SvsEnableDisable(ctx context.Context, in *SvsEnableDisab
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SvsPluginGetVersion(ctx context.Context, in *SvsPluginGetVersion) (*SvsPluginGetVersionReply, error) {
@@ -91,7 +91,7 @@ func (c *serviceClient) SvsRouteAddDel(ctx context.Context, in *SvsRouteAddDel)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SvsTableAddDel(ctx context.Context, in *SvsTableAddDel) (*SvsTableAddDelReply, error) {
@@ -100,5 +100,5 @@ func (c *serviceClient) SvsTableAddDel(ctx context.Context, in *SvsTableAddDel)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/syslog/syslog.ba.go b/binapi/syslog/syslog.ba.go
index cf8f754..e3b7ef5 100644
--- a/binapi/syslog/syslog.ba.go
+++ b/binapi/syslog/syslog.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/syslog.api.json
 
 // Package syslog contains generated bindings for API file syslog.api.
diff --git a/binapi/syslog/syslog_rest.ba.go b/binapi/syslog/syslog_rest.ba.go
deleted file mode 100644
index e9098e8..0000000
--- a/binapi/syslog/syslog_rest.ba.go
+++ /dev/null
@@ -1,88 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package syslog
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/syslog_get_filter", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SyslogGetFilter)
-		reply, err := rpc.SyslogGetFilter(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/syslog_get_sender", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SyslogGetSender)
-		reply, err := rpc.SyslogGetSender(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/syslog_set_filter", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SyslogSetFilter)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SyslogSetFilter(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/syslog_set_sender", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SyslogSetSender)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SyslogSetSender(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/syslog/syslog_rpc.ba.go b/binapi/syslog/syslog_rpc.ba.go
index 385960f..da005b3 100644
--- a/binapi/syslog/syslog_rpc.ba.go
+++ b/binapi/syslog/syslog_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  syslog.
+// RPCService defines RPC service syslog.
 type RPCService interface {
 	SyslogGetFilter(ctx context.Context, in *SyslogGetFilter) (*SyslogGetFilterReply, error)
 	SyslogGetSender(ctx context.Context, in *SyslogGetSender) (*SyslogGetSenderReply, error)
@@ -30,7 +30,7 @@ func (c *serviceClient) SyslogGetFilter(ctx context.Context, in *SyslogGetFilter
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SyslogGetSender(ctx context.Context, in *SyslogGetSender) (*SyslogGetSenderReply, error) {
@@ -39,7 +39,7 @@ func (c *serviceClient) SyslogGetSender(ctx context.Context, in *SyslogGetSender
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SyslogSetFilter(ctx context.Context, in *SyslogSetFilter) (*SyslogSetFilterReply, error) {
@@ -48,7 +48,7 @@ func (c *serviceClient) SyslogSetFilter(ctx context.Context, in *SyslogSetFilter
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SyslogSetSender(ctx context.Context, in *SyslogSetSender) (*SyslogSetSenderReply, error) {
@@ -57,5 +57,5 @@ func (c *serviceClient) SyslogSetSender(ctx context.Context, in *SyslogSetSender
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/tapv2/tapv2.ba.go b/binapi/tapv2/tapv2.ba.go
index 028ff67..db9f4ba 100644
--- a/binapi/tapv2/tapv2.ba.go
+++ b/binapi/tapv2/tapv2.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/tapv2.api.json
 
 // Package tapv2 contains generated bindings for API file tapv2.api.
diff --git a/binapi/tapv2/tapv2_rest.ba.go b/binapi/tapv2/tapv2_rest.ba.go
deleted file mode 100644
index b1d1111..0000000
--- a/binapi/tapv2/tapv2_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package tapv2
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/tap_create_v2", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(TapCreateV2)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.TapCreateV2(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/tap_delete_v2", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(TapDeleteV2)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.TapDeleteV2(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/tapv2/tapv2_rpc.ba.go b/binapi/tapv2/tapv2_rpc.ba.go
index 7742fd3..3b58f9d 100644
--- a/binapi/tapv2/tapv2_rpc.ba.go
+++ b/binapi/tapv2/tapv2_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  tapv2.
+// RPCService defines RPC service tapv2.
 type RPCService interface {
 	SwInterfaceTapV2Dump(ctx context.Context, in *SwInterfaceTapV2Dump) (RPCService_SwInterfaceTapV2DumpClient, error)
 	TapCreateV2(ctx context.Context, in *TapCreateV2) (*TapCreateV2Reply, error)
@@ -71,7 +71,7 @@ func (c *serviceClient) TapCreateV2(ctx context.Context, in *TapCreateV2) (*TapC
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) TapDeleteV2(ctx context.Context, in *TapDeleteV2) (*TapDeleteV2Reply, error) {
@@ -80,5 +80,5 @@ func (c *serviceClient) TapDeleteV2(ctx context.Context, in *TapDeleteV2) (*TapD
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/tcp/tcp.ba.go b/binapi/tcp/tcp.ba.go
index 7ae3ecc..bfa9df7 100644
--- a/binapi/tcp/tcp.ba.go
+++ b/binapi/tcp/tcp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/tcp.api.json
 
 // Package tcp contains generated bindings for API file tcp.api.
diff --git a/binapi/tcp/tcp_rest.ba.go b/binapi/tcp/tcp_rest.ba.go
deleted file mode 100644
index 8fa0b79..0000000
--- a/binapi/tcp/tcp_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package tcp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/tcp_configure_src_addresses", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(TCPConfigureSrcAddresses)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.TCPConfigureSrcAddresses(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/tcp/tcp_rpc.ba.go b/binapi/tcp/tcp_rpc.ba.go
index a87c7e5..2d045f7 100644
--- a/binapi/tcp/tcp_rpc.ba.go
+++ b/binapi/tcp/tcp_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  tcp.
+// RPCService defines RPC service tcp.
 type RPCService interface {
 	TCPConfigureSrcAddresses(ctx context.Context, in *TCPConfigureSrcAddresses) (*TCPConfigureSrcAddressesReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) TCPConfigureSrcAddresses(ctx context.Context, in *TCPCon
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/teib/teib.ba.go b/binapi/teib/teib.ba.go
index d37f391..6a10688 100644
--- a/binapi/teib/teib.ba.go
+++ b/binapi/teib/teib.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/teib.api.json
 
 // Package teib contains generated bindings for API file teib.api.
diff --git a/binapi/teib/teib_rest.ba.go b/binapi/teib/teib_rest.ba.go
deleted file mode 100644
index fb8bc17..0000000
--- a/binapi/teib/teib_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package teib
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/teib_entry_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(TeibEntryAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.TeibEntryAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/teib/teib_rpc.ba.go b/binapi/teib/teib_rpc.ba.go
index 579f9e5..87fcdcd 100644
--- a/binapi/teib/teib_rpc.ba.go
+++ b/binapi/teib/teib_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  teib.
+// RPCService defines RPC service teib.
 type RPCService interface {
 	TeibDump(ctx context.Context, in *TeibDump) (RPCService_TeibDumpClient, error)
 	TeibEntryAddDel(ctx context.Context, in *TeibEntryAddDel) (*TeibEntryAddDelReply, error)
@@ -70,5 +70,5 @@ func (c *serviceClient) TeibEntryAddDel(ctx context.Context, in *TeibEntryAddDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/tls_openssl/tls_openssl.ba.go b/binapi/tls_openssl/tls_openssl.ba.go
index 938a9df..5a406b0 100644
--- a/binapi/tls_openssl/tls_openssl.ba.go
+++ b/binapi/tls_openssl/tls_openssl.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/tls_openssl.api.json
 
 // Package tls_openssl contains generated bindings for API file tls_openssl.api.
diff --git a/binapi/tls_openssl/tls_openssl_rest.ba.go b/binapi/tls_openssl/tls_openssl_rest.ba.go
deleted file mode 100644
index bfabb43..0000000
--- a/binapi/tls_openssl/tls_openssl_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package tls_openssl
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/tls_openssl_set_engine", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(TLSOpensslSetEngine)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.TLSOpensslSetEngine(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/tls_openssl/tls_openssl_rpc.ba.go b/binapi/tls_openssl/tls_openssl_rpc.ba.go
index 69a5de5..57ef26d 100644
--- a/binapi/tls_openssl/tls_openssl_rpc.ba.go
+++ b/binapi/tls_openssl/tls_openssl_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  tls_openssl.
+// RPCService defines RPC service tls_openssl.
 type RPCService interface {
 	TLSOpensslSetEngine(ctx context.Context, in *TLSOpensslSetEngine) (*TLSOpensslSetEngineReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) TLSOpensslSetEngine(ctx context.Context, in *TLSOpensslS
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/trace/trace.ba.go b/binapi/trace/trace.ba.go
index 9bc330b..a789b4f 100644
--- a/binapi/trace/trace.ba.go
+++ b/binapi/trace/trace.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/trace.api.json
 
 // Package trace contains generated bindings for API file trace.api.
diff --git a/binapi/trace/trace_rest.ba.go b/binapi/trace/trace_rest.ba.go
deleted file mode 100644
index d7d2244..0000000
--- a/binapi/trace/trace_rest.ba.go
+++ /dev/null
@@ -1,65 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package trace
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/trace_profile_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(TraceProfileAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.TraceProfileAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/trace_profile_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(TraceProfileDel)
-		reply, err := rpc.TraceProfileDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/trace_profile_show_config", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(TraceProfileShowConfig)
-		reply, err := rpc.TraceProfileShowConfig(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/trace/trace_rpc.ba.go b/binapi/trace/trace_rpc.ba.go
index 09bf889..e3f1eca 100644
--- a/binapi/trace/trace_rpc.ba.go
+++ b/binapi/trace/trace_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  trace.
+// RPCService defines RPC service trace.
 type RPCService interface {
 	TraceProfileAdd(ctx context.Context, in *TraceProfileAdd) (*TraceProfileAddReply, error)
 	TraceProfileDel(ctx context.Context, in *TraceProfileDel) (*TraceProfileDelReply, error)
@@ -29,7 +29,7 @@ func (c *serviceClient) TraceProfileAdd(ctx context.Context, in *TraceProfileAdd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) TraceProfileDel(ctx context.Context, in *TraceProfileDel) (*TraceProfileDelReply, error) {
@@ -38,7 +38,7 @@ func (c *serviceClient) TraceProfileDel(ctx context.Context, in *TraceProfileDel
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) TraceProfileShowConfig(ctx context.Context, in *TraceProfileShowConfig) (*TraceProfileShowConfigReply, error) {
@@ -47,5 +47,5 @@ func (c *serviceClient) TraceProfileShowConfig(ctx context.Context, in *TracePro
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/tunnel_types/tunnel_types.ba.go b/binapi/tunnel_types/tunnel_types.ba.go
index a79ee18..3fff34c 100644
--- a/binapi/tunnel_types/tunnel_types.ba.go
+++ b/binapi/tunnel_types/tunnel_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/tunnel_types.api.json
 
 // Package tunnel_types contains generated bindings for API file tunnel_types.api.
diff --git a/binapi/udp/udp.ba.go b/binapi/udp/udp.ba.go
index 7795100..bb2924c 100644
--- a/binapi/udp/udp.ba.go
+++ b/binapi/udp/udp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/udp.api.json
 
 // Package udp contains generated bindings for API file udp.api.
diff --git a/binapi/udp/udp_rest.ba.go b/binapi/udp/udp_rest.ba.go
deleted file mode 100644
index fc584bb..0000000
--- a/binapi/udp/udp_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package udp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/udp_encap_add", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(UDPEncapAdd)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.UDPEncapAdd(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/udp_encap_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(UDPEncapDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.UDPEncapDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/udp/udp_rpc.ba.go b/binapi/udp/udp_rpc.ba.go
index 8d99214..0b17c63 100644
--- a/binapi/udp/udp_rpc.ba.go
+++ b/binapi/udp/udp_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  udp.
+// RPCService defines RPC service udp.
 type RPCService interface {
 	UDPEncapAdd(ctx context.Context, in *UDPEncapAdd) (*UDPEncapAddReply, error)
 	UDPEncapDel(ctx context.Context, in *UDPEncapDel) (*UDPEncapDelReply, error)
@@ -32,7 +32,7 @@ func (c *serviceClient) UDPEncapAdd(ctx context.Context, in *UDPEncapAdd) (*UDPE
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) UDPEncapDel(ctx context.Context, in *UDPEncapDel) (*UDPEncapDelReply, error) {
@@ -41,7 +41,7 @@ func (c *serviceClient) UDPEncapDel(ctx context.Context, in *UDPEncapDel) (*UDPE
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) UDPEncapDump(ctx context.Context, in *UDPEncapDump) (RPCService_UDPEncapDumpClient, error) {
diff --git a/binapi/udp_ping/udp_ping.ba.go b/binapi/udp_ping/udp_ping.ba.go
index 7247b38..a568fce 100644
--- a/binapi/udp_ping/udp_ping.ba.go
+++ b/binapi/udp_ping/udp_ping.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/udp_ping.api.json
 
 // Package udp_ping contains generated bindings for API file udp_ping.api.
diff --git a/binapi/udp_ping/udp_ping_rest.ba.go b/binapi/udp_ping/udp_ping_rest.ba.go
deleted file mode 100644
index 41317c4..0000000
--- a/binapi/udp_ping/udp_ping_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package udp_ping
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/udp_ping_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(UDPPingAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.UDPPingAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/udp_ping_export", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(UDPPingExport)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.UDPPingExport(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/udp_ping/udp_ping_rpc.ba.go b/binapi/udp_ping/udp_ping_rpc.ba.go
index 4aa51f6..3b01ff7 100644
--- a/binapi/udp_ping/udp_ping_rpc.ba.go
+++ b/binapi/udp_ping/udp_ping_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  udp_ping.
+// RPCService defines RPC service udp_ping.
 type RPCService interface {
 	UDPPingAddDel(ctx context.Context, in *UDPPingAddDel) (*UDPPingAddDelReply, error)
 	UDPPingExport(ctx context.Context, in *UDPPingExport) (*UDPPingExportReply, error)
@@ -28,7 +28,7 @@ func (c *serviceClient) UDPPingAddDel(ctx context.Context, in *UDPPingAddDel) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) UDPPingExport(ctx context.Context, in *UDPPingExport) (*UDPPingExportReply, error) {
@@ -37,5 +37,5 @@ func (c *serviceClient) UDPPingExport(ctx context.Context, in *UDPPingExport) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/urpf/urpf.ba.go b/binapi/urpf/urpf.ba.go
index e277537..62a335c 100644
--- a/binapi/urpf/urpf.ba.go
+++ b/binapi/urpf/urpf.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/urpf.api.json
 
 // Package urpf contains generated bindings for API file urpf.api.
diff --git a/binapi/urpf/urpf_rest.ba.go b/binapi/urpf/urpf_rest.ba.go
deleted file mode 100644
index cbe7875..0000000
--- a/binapi/urpf/urpf_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package urpf
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/urpf_update", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(UrpfUpdate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.UrpfUpdate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/urpf/urpf_rpc.ba.go b/binapi/urpf/urpf_rpc.ba.go
index 04d4b56..ef10d4b 100644
--- a/binapi/urpf/urpf_rpc.ba.go
+++ b/binapi/urpf/urpf_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  urpf.
+// RPCService defines RPC service urpf.
 type RPCService interface {
 	UrpfUpdate(ctx context.Context, in *UrpfUpdate) (*UrpfUpdateReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) UrpfUpdate(ctx context.Context, in *UrpfUpdate) (*UrpfUp
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/vhost_user/vhost_user.ba.go b/binapi/vhost_user/vhost_user.ba.go
index 0ca7119..f5fbdd5 100644
--- a/binapi/vhost_user/vhost_user.ba.go
+++ b/binapi/vhost_user/vhost_user.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/vhost_user.api.json
 
 // Package vhost_user contains generated bindings for API file vhost_user.api.
diff --git a/binapi/vhost_user/vhost_user_rest.ba.go b/binapi/vhost_user/vhost_user_rest.ba.go
deleted file mode 100644
index c2f687b..0000000
--- a/binapi/vhost_user/vhost_user_rest.ba.go
+++ /dev/null
@@ -1,83 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package vhost_user
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/create_vhost_user_if", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(CreateVhostUserIf)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.CreateVhostUserIf(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/delete_vhost_user_if", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(DeleteVhostUserIf)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.DeleteVhostUserIf(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/modify_vhost_user_if", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ModifyVhostUserIf)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.ModifyVhostUserIf(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/vhost_user/vhost_user_rpc.ba.go b/binapi/vhost_user/vhost_user_rpc.ba.go
index 6e18a51..445e2eb 100644
--- a/binapi/vhost_user/vhost_user_rpc.ba.go
+++ b/binapi/vhost_user/vhost_user_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  vhost_user.
+// RPCService defines RPC service vhost_user.
 type RPCService interface {
 	CreateVhostUserIf(ctx context.Context, in *CreateVhostUserIf) (*CreateVhostUserIfReply, error)
 	DeleteVhostUserIf(ctx context.Context, in *DeleteVhostUserIf) (*DeleteVhostUserIfReply, error)
@@ -33,7 +33,7 @@ func (c *serviceClient) CreateVhostUserIf(ctx context.Context, in *CreateVhostUs
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) DeleteVhostUserIf(ctx context.Context, in *DeleteVhostUserIf) (*DeleteVhostUserIfReply, error) {
@@ -42,7 +42,7 @@ func (c *serviceClient) DeleteVhostUserIf(ctx context.Context, in *DeleteVhostUs
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ModifyVhostUserIf(ctx context.Context, in *ModifyVhostUserIf) (*ModifyVhostUserIfReply, error) {
@@ -51,7 +51,7 @@ func (c *serviceClient) ModifyVhostUserIf(ctx context.Context, in *ModifyVhostUs
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) SwInterfaceVhostUserDump(ctx context.Context, in *SwInterfaceVhostUserDump) (RPCService_SwInterfaceVhostUserDumpClient, error) {
diff --git a/binapi/virtio/virtio.ba.go b/binapi/virtio/virtio.ba.go
index b29b52f..6234a17 100644
--- a/binapi/virtio/virtio.ba.go
+++ b/binapi/virtio/virtio.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/virtio.api.json
 
 // Package virtio contains generated bindings for API file virtio.api.
diff --git a/binapi/virtio/virtio_rest.ba.go b/binapi/virtio/virtio_rest.ba.go
deleted file mode 100644
index bd97059..0000000
--- a/binapi/virtio/virtio_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package virtio
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/virtio_pci_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VirtioPciCreate)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VirtioPciCreate(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/virtio_pci_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VirtioPciDelete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VirtioPciDelete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/virtio/virtio_rpc.ba.go b/binapi/virtio/virtio_rpc.ba.go
index 4fa4bb1..4ee8ff7 100644
--- a/binapi/virtio/virtio_rpc.ba.go
+++ b/binapi/virtio/virtio_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  virtio.
+// RPCService defines RPC service virtio.
 type RPCService interface {
 	SwInterfaceVirtioPciDump(ctx context.Context, in *SwInterfaceVirtioPciDump) (RPCService_SwInterfaceVirtioPciDumpClient, error)
 	VirtioPciCreate(ctx context.Context, in *VirtioPciCreate) (*VirtioPciCreateReply, error)
@@ -71,7 +71,7 @@ func (c *serviceClient) VirtioPciCreate(ctx context.Context, in *VirtioPciCreate
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VirtioPciDelete(ctx context.Context, in *VirtioPciDelete) (*VirtioPciDeleteReply, error) {
@@ -80,5 +80,5 @@ func (c *serviceClient) VirtioPciDelete(ctx context.Context, in *VirtioPciDelete
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/virtio_types/virtio_types.ba.go b/binapi/virtio_types/virtio_types.ba.go
index d78740a..587d7c5 100644
--- a/binapi/virtio_types/virtio_types.ba.go
+++ b/binapi/virtio_types/virtio_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/virtio_types.api.json
 
 // Package virtio_types contains generated bindings for API file virtio_types.api.
diff --git a/binapi/vmxnet3/vmxnet3.ba.go b/binapi/vmxnet3/vmxnet3.ba.go
index 77937fa..5aca3c9 100644
--- a/binapi/vmxnet3/vmxnet3.ba.go
+++ b/binapi/vmxnet3/vmxnet3.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/vmxnet3.api.json
 
 // Package vmxnet3 contains generated bindings for API file vmxnet3.api.
diff --git a/binapi/vmxnet3/vmxnet3_rest.ba.go b/binapi/vmxnet3/vmxnet3_rest.ba.go
deleted file mode 100644
index 3280f8c..0000000
--- a/binapi/vmxnet3/vmxnet3_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package vmxnet3
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/vmxnet3_create", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Vmxnet3Create)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Vmxnet3Create(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vmxnet3_delete", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Vmxnet3Delete)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Vmxnet3Delete(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/vmxnet3/vmxnet3_rpc.ba.go b/binapi/vmxnet3/vmxnet3_rpc.ba.go
index facc468..a05819c 100644
--- a/binapi/vmxnet3/vmxnet3_rpc.ba.go
+++ b/binapi/vmxnet3/vmxnet3_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  vmxnet3.
+// RPCService defines RPC service vmxnet3.
 type RPCService interface {
 	Vmxnet3Create(ctx context.Context, in *Vmxnet3Create) (*Vmxnet3CreateReply, error)
 	Vmxnet3Delete(ctx context.Context, in *Vmxnet3Delete) (*Vmxnet3DeleteReply, error)
@@ -32,7 +32,7 @@ func (c *serviceClient) Vmxnet3Create(ctx context.Context, in *Vmxnet3Create) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Vmxnet3Delete(ctx context.Context, in *Vmxnet3Delete) (*Vmxnet3DeleteReply, error) {
@@ -41,7 +41,7 @@ func (c *serviceClient) Vmxnet3Delete(ctx context.Context, in *Vmxnet3Delete) (*
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Vmxnet3Dump(ctx context.Context, in *Vmxnet3Dump) (RPCService_Vmxnet3DumpClient, error) {
diff --git a/binapi/vpe/vpe.ba.go b/binapi/vpe/vpe.ba.go
index 046bd68..656a68a 100644
--- a/binapi/vpe/vpe.ba.go
+++ b/binapi/vpe/vpe.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/vpe.api.json
 
 // Package vpe contains generated bindings for API file vpe.api.
diff --git a/binapi/vpe/vpe_rest.ba.go b/binapi/vpe/vpe_rest.ba.go
deleted file mode 100644
index 2f92a62..0000000
--- a/binapi/vpe/vpe_rest.ba.go
+++ /dev/null
@@ -1,245 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package vpe
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/add_node_next", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(AddNodeNext)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.AddNodeNext(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/cli", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(Cli)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.Cli(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/cli_inband", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(CliInband)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.CliInband(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/control_ping", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ControlPing)
-		reply, err := rpc.ControlPing(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/get_f64_endian_value", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GetF64EndianValue)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GetF64EndianValue(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/get_f64_increment_by_one", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GetF64IncrementByOne)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GetF64IncrementByOne(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/get_next_index", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GetNextIndex)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GetNextIndex(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/get_node_graph", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GetNodeGraph)
-		reply, err := rpc.GetNodeGraph(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/get_node_index", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(GetNodeIndex)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.GetNodeIndex(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_threads", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowThreads)
-		reply, err := rpc.ShowThreads(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_version", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowVersion)
-		reply, err := rpc.ShowVersion(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/show_vpe_system_time", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(ShowVpeSystemTime)
-		reply, err := rpc.ShowVpeSystemTime(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/vpe/vpe_rpc.ba.go b/binapi/vpe/vpe_rpc.ba.go
index e41f5f8..fd3901b 100644
--- a/binapi/vpe/vpe_rpc.ba.go
+++ b/binapi/vpe/vpe_rpc.ba.go
@@ -10,7 +10,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  vpe.
+// RPCService defines RPC service vpe.
 type RPCService interface {
 	AddNodeNext(ctx context.Context, in *AddNodeNext) (*AddNodeNextReply, error)
 	Cli(ctx context.Context, in *Cli) (*CliReply, error)
@@ -41,7 +41,7 @@ func (c *serviceClient) AddNodeNext(ctx context.Context, in *AddNodeNext) (*AddN
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) Cli(ctx context.Context, in *Cli) (*CliReply, error) {
@@ -50,7 +50,7 @@ func (c *serviceClient) Cli(ctx context.Context, in *Cli) (*CliReply, error) {
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) CliInband(ctx context.Context, in *CliInband) (*CliInbandReply, error) {
@@ -59,7 +59,7 @@ func (c *serviceClient) CliInband(ctx context.Context, in *CliInband) (*CliInban
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ControlPing(ctx context.Context, in *ControlPing) (*ControlPingReply, error) {
@@ -68,7 +68,7 @@ func (c *serviceClient) ControlPing(ctx context.Context, in *ControlPing) (*Cont
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GetF64EndianValue(ctx context.Context, in *GetF64EndianValue) (*GetF64EndianValueReply, error) {
@@ -77,7 +77,7 @@ func (c *serviceClient) GetF64EndianValue(ctx context.Context, in *GetF64EndianV
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(int32(out.Retval))
 }
 
 func (c *serviceClient) GetF64IncrementByOne(ctx context.Context, in *GetF64IncrementByOne) (*GetF64IncrementByOneReply, error) {
@@ -86,7 +86,7 @@ func (c *serviceClient) GetF64IncrementByOne(ctx context.Context, in *GetF64Incr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(int32(out.Retval))
 }
 
 func (c *serviceClient) GetNextIndex(ctx context.Context, in *GetNextIndex) (*GetNextIndexReply, error) {
@@ -95,7 +95,7 @@ func (c *serviceClient) GetNextIndex(ctx context.Context, in *GetNextIndex) (*Ge
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GetNodeGraph(ctx context.Context, in *GetNodeGraph) (*GetNodeGraphReply, error) {
@@ -104,7 +104,7 @@ func (c *serviceClient) GetNodeGraph(ctx context.Context, in *GetNodeGraph) (*Ge
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) GetNodeIndex(ctx context.Context, in *GetNodeIndex) (*GetNodeIndexReply, error) {
@@ -113,7 +113,7 @@ func (c *serviceClient) GetNodeIndex(ctx context.Context, in *GetNodeIndex) (*Ge
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) LogDump(ctx context.Context, in *LogDump) (RPCService_LogDumpClient, error) {
@@ -161,7 +161,7 @@ func (c *serviceClient) ShowThreads(ctx context.Context, in *ShowThreads) (*Show
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowVersion(ctx context.Context, in *ShowVersion) (*ShowVersionReply, error) {
@@ -170,7 +170,7 @@ func (c *serviceClient) ShowVersion(ctx context.Context, in *ShowVersion) (*Show
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) ShowVpeSystemTime(ctx context.Context, in *ShowVpeSystemTime) (*ShowVpeSystemTimeReply, error) {
@@ -179,5 +179,5 @@ func (c *serviceClient) ShowVpeSystemTime(ctx context.Context, in *ShowVpeSystem
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
diff --git a/binapi/vpe_types/vpe_types.ba.go b/binapi/vpe_types/vpe_types.ba.go
index f1d21b0..473880d 100644
--- a/binapi/vpe_types/vpe_types.ba.go
+++ b/binapi/vpe_types/vpe_types.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/vpe_types.api.json
 
 // Package vpe_types contains generated bindings for API file vpe_types.api.
diff --git a/binapi/vrrp/vrrp.ba.go b/binapi/vrrp/vrrp.ba.go
index b00f281..f9f33f6 100644
--- a/binapi/vrrp/vrrp.ba.go
+++ b/binapi/vrrp/vrrp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/vrrp.api.json
 
 // Package vrrp contains generated bindings for API file vrrp.api.
diff --git a/binapi/vrrp/vrrp_rest.ba.go b/binapi/vrrp/vrrp_rest.ba.go
deleted file mode 100644
index 35cedfe..0000000
--- a/binapi/vrrp/vrrp_rest.ba.go
+++ /dev/null
@@ -1,106 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package vrrp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/vrrp_vr_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VrrpVrAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VrrpVrAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vrrp_vr_set_peers", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VrrpVrSetPeers)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VrrpVrSetPeers(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vrrp_vr_start_stop", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VrrpVrStartStop)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VrrpVrStartStop(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vrrp_vr_track_if_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VrrpVrTrackIfAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VrrpVrTrackIfAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/vrrp/vrrp_rpc.ba.go b/binapi/vrrp/vrrp_rpc.ba.go
index 12be3c8..ae19b0f 100644
--- a/binapi/vrrp/vrrp_rpc.ba.go
+++ b/binapi/vrrp/vrrp_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  vrrp.
+// RPCService defines RPC service vrrp.
 type RPCService interface {
 	VrrpVrAddDel(ctx context.Context, in *VrrpVrAddDel) (*VrrpVrAddDelReply, error)
 	VrrpVrDump(ctx context.Context, in *VrrpVrDump) (RPCService_VrrpVrDumpClient, error)
@@ -36,7 +36,7 @@ func (c *serviceClient) VrrpVrAddDel(ctx context.Context, in *VrrpVrAddDel) (*Vr
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VrrpVrDump(ctx context.Context, in *VrrpVrDump) (RPCService_VrrpVrDumpClient, error) {
@@ -123,7 +123,7 @@ func (c *serviceClient) VrrpVrSetPeers(ctx context.Context, in *VrrpVrSetPeers)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VrrpVrStartStop(ctx context.Context, in *VrrpVrStartStop) (*VrrpVrStartStopReply, error) {
@@ -132,7 +132,7 @@ func (c *serviceClient) VrrpVrStartStop(ctx context.Context, in *VrrpVrStartStop
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VrrpVrTrackIfAddDel(ctx context.Context, in *VrrpVrTrackIfAddDel) (*VrrpVrTrackIfAddDelReply, error) {
@@ -141,7 +141,7 @@ func (c *serviceClient) VrrpVrTrackIfAddDel(ctx context.Context, in *VrrpVrTrack
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VrrpVrTrackIfDump(ctx context.Context, in *VrrpVrTrackIfDump) (RPCService_VrrpVrTrackIfDumpClient, error) {
diff --git a/binapi/vxlan/vxlan.ba.go b/binapi/vxlan/vxlan.ba.go
index 048b2fa..fe7c5fb 100644
--- a/binapi/vxlan/vxlan.ba.go
+++ b/binapi/vxlan/vxlan.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/vxlan.api.json
 
 // Package vxlan contains generated bindings for API file vxlan.api.
diff --git a/binapi/vxlan/vxlan_rest.ba.go b/binapi/vxlan/vxlan_rest.ba.go
deleted file mode 100644
index ee35144..0000000
--- a/binapi/vxlan/vxlan_rest.ba.go
+++ /dev/null
@@ -1,83 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package vxlan
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/sw_interface_set_vxlan_bypass", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetVxlanBypass)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetVxlanBypass(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vxlan_add_del_tunnel", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanAddDelTunnel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanAddDelTunnel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vxlan_offload_rx", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanOffloadRx)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanOffloadRx(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/vxlan/vxlan_rpc.ba.go b/binapi/vxlan/vxlan_rpc.ba.go
index 34692bb..0ae30a5 100644
--- a/binapi/vxlan/vxlan_rpc.ba.go
+++ b/binapi/vxlan/vxlan_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  vxlan.
+// RPCService defines RPC service vxlan.
 type RPCService interface {
 	SwInterfaceSetVxlanBypass(ctx context.Context, in *SwInterfaceSetVxlanBypass) (*SwInterfaceSetVxlanBypassReply, error)
 	VxlanAddDelTunnel(ctx context.Context, in *VxlanAddDelTunnel) (*VxlanAddDelTunnelReply, error)
@@ -33,7 +33,7 @@ func (c *serviceClient) SwInterfaceSetVxlanBypass(ctx context.Context, in *SwInt
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanAddDelTunnel(ctx context.Context, in *VxlanAddDelTunnel) (*VxlanAddDelTunnelReply, error) {
@@ -42,7 +42,7 @@ func (c *serviceClient) VxlanAddDelTunnel(ctx context.Context, in *VxlanAddDelTu
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanOffloadRx(ctx context.Context, in *VxlanOffloadRx) (*VxlanOffloadRxReply, error) {
@@ -51,7 +51,7 @@ func (c *serviceClient) VxlanOffloadRx(ctx context.Context, in *VxlanOffloadRx)
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanTunnelDump(ctx context.Context, in *VxlanTunnelDump) (RPCService_VxlanTunnelDumpClient, error) {
diff --git a/binapi/vxlan_gbp/vxlan_gbp.ba.go b/binapi/vxlan_gbp/vxlan_gbp.ba.go
index 0876906..bd92319 100644
--- a/binapi/vxlan_gbp/vxlan_gbp.ba.go
+++ b/binapi/vxlan_gbp/vxlan_gbp.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/vxlan_gbp.api.json
 
 // Package vxlan_gbp contains generated bindings for API file vxlan_gbp.api.
diff --git a/binapi/vxlan_gbp/vxlan_gbp_rest.ba.go b/binapi/vxlan_gbp/vxlan_gbp_rest.ba.go
deleted file mode 100644
index 5d94785..0000000
--- a/binapi/vxlan_gbp/vxlan_gbp_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package vxlan_gbp
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/sw_interface_set_vxlan_gbp_bypass", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetVxlanGbpBypass)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetVxlanGbpBypass(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vxlan_gbp_tunnel_add_del", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanGbpTunnelAddDel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanGbpTunnelAddDel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/vxlan_gbp/vxlan_gbp_rpc.ba.go b/binapi/vxlan_gbp/vxlan_gbp_rpc.ba.go
index 403230a..c86edb9 100644
--- a/binapi/vxlan_gbp/vxlan_gbp_rpc.ba.go
+++ b/binapi/vxlan_gbp/vxlan_gbp_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  vxlan_gbp.
+// RPCService defines RPC service vxlan_gbp.
 type RPCService interface {
 	SwInterfaceSetVxlanGbpBypass(ctx context.Context, in *SwInterfaceSetVxlanGbpBypass) (*SwInterfaceSetVxlanGbpBypassReply, error)
 	VxlanGbpTunnelAddDel(ctx context.Context, in *VxlanGbpTunnelAddDel) (*VxlanGbpTunnelAddDelReply, error)
@@ -32,7 +32,7 @@ func (c *serviceClient) SwInterfaceSetVxlanGbpBypass(ctx context.Context, in *Sw
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanGbpTunnelAddDel(ctx context.Context, in *VxlanGbpTunnelAddDel) (*VxlanGbpTunnelAddDelReply, error) {
@@ -41,7 +41,7 @@ func (c *serviceClient) VxlanGbpTunnelAddDel(ctx context.Context, in *VxlanGbpTu
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanGbpTunnelDump(ctx context.Context, in *VxlanGbpTunnelDump) (RPCService_VxlanGbpTunnelDumpClient, error) {
diff --git a/binapi/vxlan_gpe/vxlan_gpe.ba.go b/binapi/vxlan_gpe/vxlan_gpe.ba.go
index 0858ada..f34c328 100644
--- a/binapi/vxlan_gpe/vxlan_gpe.ba.go
+++ b/binapi/vxlan_gpe/vxlan_gpe.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/core/vxlan_gpe.api.json
 
 // Package vxlan_gpe contains generated bindings for API file vxlan_gpe.api.
diff --git a/binapi/vxlan_gpe/vxlan_gpe_rest.ba.go b/binapi/vxlan_gpe/vxlan_gpe_rest.ba.go
deleted file mode 100644
index 0761ca3..0000000
--- a/binapi/vxlan_gpe/vxlan_gpe_rest.ba.go
+++ /dev/null
@@ -1,60 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package vxlan_gpe
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/sw_interface_set_vxlan_gpe_bypass", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(SwInterfaceSetVxlanGpeBypass)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.SwInterfaceSetVxlanGpeBypass(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	mux.HandleFunc("/vxlan_gpe_add_del_tunnel", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanGpeAddDelTunnel)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanGpeAddDelTunnel(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/vxlan_gpe/vxlan_gpe_rpc.ba.go b/binapi/vxlan_gpe/vxlan_gpe_rpc.ba.go
index 13c2a1c..787a053 100644
--- a/binapi/vxlan_gpe/vxlan_gpe_rpc.ba.go
+++ b/binapi/vxlan_gpe/vxlan_gpe_rpc.ba.go
@@ -11,7 +11,7 @@ import (
 	vpe "git.fd.io/govpp.git/binapi/vpe"
 )
 
-// RPCService defines RPC service  vxlan_gpe.
+// RPCService defines RPC service vxlan_gpe.
 type RPCService interface {
 	SwInterfaceSetVxlanGpeBypass(ctx context.Context, in *SwInterfaceSetVxlanGpeBypass) (*SwInterfaceSetVxlanGpeBypassReply, error)
 	VxlanGpeAddDelTunnel(ctx context.Context, in *VxlanGpeAddDelTunnel) (*VxlanGpeAddDelTunnelReply, error)
@@ -32,7 +32,7 @@ func (c *serviceClient) SwInterfaceSetVxlanGpeBypass(ctx context.Context, in *Sw
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanGpeAddDelTunnel(ctx context.Context, in *VxlanGpeAddDelTunnel) (*VxlanGpeAddDelTunnelReply, error) {
@@ -41,7 +41,7 @@ func (c *serviceClient) VxlanGpeAddDelTunnel(ctx context.Context, in *VxlanGpeAd
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }
 
 func (c *serviceClient) VxlanGpeTunnelDump(ctx context.Context, in *VxlanGpeTunnelDump) (RPCService_VxlanGpeTunnelDumpClient, error) {
diff --git a/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export.ba.go b/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export.ba.go
index 8820fab..1162b59 100644
--- a/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export.ba.go
+++ b/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export.ba.go
@@ -1,7 +1,7 @@
 // Code generated by GoVPP's binapi-generator. DO NOT EDIT.
 // versions:
-//  binapi-generator: v0.4.0-dev
-//  VPP:              20.05-release
+//  binapi-generator: v0.4.0
+//  VPP:              20.05.1-release
 // source: /usr/share/vpp/api/plugins/vxlan_gpe_ioam_export.api.json
 
 // Package vxlan_gpe_ioam_export contains generated bindings for API file vxlan_gpe_ioam_export.api.
diff --git a/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export_rest.ba.go b/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export_rest.ba.go
deleted file mode 100644
index b2cf182..0000000
--- a/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export_rest.ba.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Code generated by GoVPP's binapi-generator. DO NOT EDIT.
-
-package vxlan_gpe_ioam_export
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-)
-
-func RESTHandler(rpc RPCService) http.Handler {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/vxlan_gpe_ioam_export_enable_disable", func(w http.ResponseWriter, req *http.Request) {
-		var request = new(VxlanGpeIoamExportEnableDisable)
-		b, err := ioutil.ReadAll(req.Body)
-		if err != nil {
-			http.Error(w, "read body failed", http.StatusBadRequest)
-			return
-		}
-		if err := json.Unmarshal(b, request); err != nil {
-			http.Error(w, "unmarshal data failed", http.StatusBadRequest)
-			return
-		}
-		reply, err := rpc.VxlanGpeIoamExportEnableDisable(req.Context(), request)
-		if err != nil {
-			http.Error(w, "request failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		rep, err := json.MarshalIndent(reply, "", "  ")
-		if err != nil {
-			http.Error(w, "marshal failed: "+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		w.Write(rep)
-	})
-	return http.HandlerFunc(mux.ServeHTTP)
-}
diff --git a/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export_rpc.ba.go b/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export_rpc.ba.go
index d09e3f6..f688803 100644
--- a/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export_rpc.ba.go
+++ b/binapi/vxlan_gpe_ioam_export/vxlan_gpe_ioam_export_rpc.ba.go
@@ -8,7 +8,7 @@ import (
 	api "git.fd.io/govpp.git/api"
 )
 
-// RPCService defines RPC service  vxlan_gpe_ioam_export.
+// RPCService defines RPC service vxlan_gpe_ioam_export.
 type RPCService interface {
 	VxlanGpeIoamExportEnableDisable(ctx context.Context, in *VxlanGpeIoamExportEnableDisable) (*VxlanGpeIoamExportEnableDisableReply, error)
 }
@@ -27,5 +27,5 @@ func (c *serviceClient) VxlanGpeIoamExportEnableDisable(ctx context.Context, in
 	if err != nil {
 		return nil, err
 	}
-	return out, nil
+	return out, api.RetvalToVPPApiError(out.Retval)
 }