diff --git a/openapiv3.go b/openapiv3.go
index 499edeb..f0dffb4 100644
--- a/openapiv3.go
+++ b/openapiv3.go
@@ -24,7 +24,7 @@ import (
 	"strings"
 
 	"go.unistack.org/micro-proto/v3/api"
-	v2 "go.unistack.org/micro-proto/v3/openapiv2"
+	// v2 "go.unistack.org/micro-proto/v3/openapiv2"
 	v3 "go.unistack.org/micro-proto/v3/openapiv3"
 	"google.golang.org/protobuf/compiler/protogen"
 	"google.golang.org/protobuf/proto"
@@ -245,12 +245,14 @@ func (g *openapiv3Generator) addPathsToDocumentV3(d *v3.Document, file *protogen
 			outputMessage := method.Output
 			operationID := service.GoName + "_" + method.GoName
 
-			e2opt := proto.GetExtension(method.Desc.Options(), v2.E_Openapiv2Operation)
-			if e2opt != nil && e2opt != v2.E_Openapiv2Operation.InterfaceOf(v2.E_Openapiv2Operation.Zero()) {
-				if opt, ok := e2opt.(*v2.Operation); ok && opt.OperationId != "" {
-					operationID = opt.OperationId
+			/*
+				e2opt := proto.GetExtension(method.Desc.Options(), v2.E_Openapiv2Operation)
+				if e2opt != nil && e2opt != v2.E_Openapiv2Operation.InterfaceOf(v2.E_Openapiv2Operation.Zero()) {
+					if opt, ok := e2opt.(*v2.Operation); ok && opt.OperationId != "" {
+						operationID = opt.OperationId
+					}
 				}
-			}
+			*/
 			e3opt := proto.GetExtension(method.Desc.Options(), v3.E_Openapiv3Operation)
 			if e3opt != nil && e3opt != v3.E_Openapiv3Operation.InterfaceOf(v3.E_Openapiv3Operation.Zero()) {
 				if opt, ok := e3opt.(*v3.Operation); ok && opt.OperationId != "" {
@@ -520,6 +522,21 @@ func (g *openapiv3Generator) buildOperationV3(
 		sparameters[parameter.Name] = struct{}{}
 	}
 
+	if u, err := url.Parse(path); err == nil {
+		mp := u.Query()
+		path = u.Path
+		if mp != nil {
+			for _, field := range inputMessage.Fields {
+				fieldName := string(field.Desc.Name())
+				if _, ok := mp[fieldName]; ok && fieldName != bodyField {
+					fieldParams := g.buildQueryParamsV3(field)
+					parameters = append(parameters, fieldParams...)
+					coveredParameters = append(coveredParameters, fieldName)
+				}
+			}
+		}
+	}
+
 	// Find simple path parameters like {id}
 	if allMatches := g.pathPattern.FindAllStringSubmatch(path, -1); allMatches != nil {
 		for _, matches := range allMatches {
@@ -692,6 +709,8 @@ func (g *openapiv3Generator) buildOperationV3(
 			}
 		}
 
+		ctype := getMediaType(eopt)
+
 		op.RequestBody = &v3.RequestBodyOrReference{
 			Oneof: &v3.RequestBodyOrReference_RequestBody{
 				RequestBody: &v3.RequestBody{
@@ -699,7 +718,7 @@ func (g *openapiv3Generator) buildOperationV3(
 					Content: &v3.MediaTypes{
 						AdditionalProperties: []*v3.NamedMediaType{
 							{
-								Name: "application/json",
+								Name: ctype,
 								Value: &v3.MediaType{
 									Schema: requestSchema,
 								},
diff --git a/openapiv3_util.go b/openapiv3_util.go
new file mode 100644
index 0000000..86e8689
--- /dev/null
+++ b/openapiv3_util.go
@@ -0,0 +1,39 @@
+package main
+
+import v3 "go.unistack.org/micro-proto/v3/openapiv3"
+
+func getMediaType(eopt interface{}) string {
+	ctype := "application/json"
+
+	if eopt == nil {
+		return ctype
+	}
+
+	if eopt == v3.E_Openapiv3Operation.InterfaceOf(v3.E_Openapiv3Operation.Zero()) {
+		return ctype
+	}
+
+	opt, ok := eopt.(*v3.Operation)
+	if !ok || opt.RequestBody == nil {
+		return ctype
+	}
+
+	if opt.GetRequestBody() == nil {
+		return ctype
+	}
+
+	if opt.GetRequestBody().GetRequestBody() == nil {
+		return ctype
+	}
+
+	c := opt.GetRequestBody().GetRequestBody().GetContent()
+	if c == nil {
+		return ctype
+	}
+
+	for _, prop := range c.GetAdditionalProperties() {
+		ctype = prop.Name
+	}
+
+	return ctype
+}
diff --git a/util.go b/util.go
index 5c771b7..3dc1e63 100644
--- a/util.go
+++ b/util.go
@@ -55,6 +55,9 @@ func generateServiceClientMethods(gfile *protogen.GeneratedFile, service *protog
 				opts := proto.GetExtension(method.Desc.Options(), v2.E_Openapiv2Operation)
 				if opts != nil {
 					r := opts.(*v2.Operation)
+					if r.Responses == nil {
+						goto labelMethod
+					}
 					gfile.P("errmap := make(map[string]interface{}, ", len(r.Responses.ResponseCode), ")")
 					for _, rsp := range r.Responses.ResponseCode {
 						if schema := rsp.Value.GetJsonReference(); schema != nil {
@@ -84,8 +87,15 @@ func generateServiceClientMethods(gfile *protogen.GeneratedFile, service *protog
 				opts := proto.GetExtension(method.Desc.Options(), v3.E_Openapiv3Operation)
 				if opts != nil {
 					r := opts.(*v3.Operation)
-					gfile.P("errmap := make(map[string]interface{}, ", len(r.Responses.ResponseOrReference), ")")
-					for _, rsp := range r.Responses.ResponseOrReference {
+					if r.Responses == nil {
+						goto labelMethod
+					}
+					resps := r.Responses.ResponseOrReference
+					if r.Responses.GetDefault() != nil {
+						resps = append(resps, &v3.NamedResponseOrReference{Name: "default", Value: r.Responses.GetDefault()})
+					}
+					gfile.P("errmap := make(map[string]interface{}, ", len(resps), ")")
+					for _, rsp := range resps {
 						if schema := rsp.Value.GetReference(); schema != nil {
 							ref := schema.XRef
 							if strings.HasPrefix(ref, "."+string(service.Desc.ParentFile().Package())+".") {
@@ -110,6 +120,7 @@ func generateServiceClientMethods(gfile *protogen.GeneratedFile, service *protog
 				gfile.P(")")
 			}
 
+		labelMethod:
 			if proto.HasExtension(method.Desc.Options(), api_options.E_Http) {
 				gfile.P("opts = append(opts,")
 				endpoints, _ := generateEndpoints(method)