diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/GoClientCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/GoClientCodegen.java
index ccc712dde60..9681f435534 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/GoClientCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/GoClientCodegen.java
@@ -414,11 +414,10 @@ public class GoClientCodegen extends DefaultCodegen implements CodegenConfig {
             }
         }
 
-        // this will only import "strings" "fmt" if there are items in pathParams
+        // this will only import "fmt" if there are items in pathParams
         for (CodegenOperation operation : operations) {
             if(operation.pathParams != null && operation.pathParams.size() > 0) {
                 imports.add(createMapping("import", "fmt"));
-                imports.add(createMapping("import", "strings"));
                 break; //just need to import once
             }
         }
diff --git a/modules/swagger-codegen/src/main/resources/go/api.mustache b/modules/swagger-codegen/src/main/resources/go/api.mustache
index 9165fb21e29..d832a36a5ef 100644
--- a/modules/swagger-codegen/src/main/resources/go/api.mustache
+++ b/modules/swagger-codegen/src/main/resources/go/api.mustache
@@ -4,6 +4,7 @@ package {{packageName}}
 {{#operations}}
 import (
 	"net/url"
+	"strings"
 {{#imports}}	"{{import}}"
 {{/imports}}
 )
@@ -38,7 +39,7 @@ func New{{classname}}WithBasePath(basePath string) *{{classname}} {
  */
 func (a {{{classname}}}) {{{nickname}}}({{#allParams}}{{paramName}} {{{dataType}}}{{#hasMore}}, {{/hasMore}}{{/allParams}}) ({{#returnType}}{{^isListContainer}}*{{/isListContainer}}{{{returnType}}}, {{/returnType}}*APIResponse, error) {
 
-	var localVarHttpMethod = "{{httpMethod}}"
+	var localVarHttpMethod = strings.ToUpper("{{httpMethod}}")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "{{path}}"{{#pathParams}}
 	localVarPath = strings.Replace(localVarPath, "{"+"{{baseName}}"+"}", fmt.Sprintf("%v", {{paramName}}), -1){{/pathParams}}
@@ -93,10 +94,11 @@ func (a {{{classname}}}) {{{nickname}}}({{#allParams}}{{paramName}} {{{dataType}
 	{{^isListContainer}}
 		localVarQueryParams.Add("{{baseName}}", a.Configuration.APIClient.ParameterToString({{paramName}}, ""))
 	{{/isListContainer}}
-	{{/queryParams}}{{/hasQueryParams}}
+	{{/queryParams}}
+	{{/hasQueryParams}}
 
 	// to determine the Content-Type header
-	localVarHttpContentTypes := []string{ {{#consumes}}"{{{mediaType}}}", {{/consumes}} }
+	localVarHttpContentTypes := []string{ {{#consumes}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/consumes}} }
 
 	// set Content-Type header
 	localVarHttpContentType := a.Configuration.APIClient.SelectHeaderContentType(localVarHttpContentTypes)
@@ -105,18 +107,22 @@ func (a {{{classname}}}) {{{nickname}}}({{#allParams}}{{paramName}} {{{dataType}
 	}
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
-		{{#produces}}"{{{mediaType}}}",
-{{/produces}}	}
+		{{#produces}}
+		"{{{mediaType}}}"{{^-last}},{{/-last}}
+		{{/produces}}
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
-	}{{#hasHeaderParams}}
-
-{{#headerParams}}	// header params "{{baseName}}"
+	}
+{{#hasHeaderParams}}
+{{#headerParams}}
+	// header params "{{baseName}}"
 	localVarHeaderParams["{{baseName}}"] = a.Configuration.APIClient.ParameterToString({{paramName}}, "")
-{{/headerParams}}{{/hasHeaderParams}}
+{{/headerParams}}
+{{/hasHeaderParams}}
 {{#hasFormParams}}
 {{#formParams}}
 {{#isFile}}
@@ -132,14 +138,27 @@ func (a {{{classname}}}) {{{nickname}}}({{#allParams}}{{paramName}} {{{dataType}
 {{#hasBodyParam}}
 {{#bodyParams}}	// body params
 	localVarPostBody = &{{paramName}}
-{{/bodyParams}}{{/hasBodyParam}}
-{{#returnType}}	var successPayload = new({{returnType}}){{/returnType}}
+{{/bodyParams}}
+{{/hasBodyParam}}
+{{#returnType}}
+	var successPayload = new({{returnType}})
+{{/returnType}}
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "{{operationId}}", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return {{#returnType}}{{#isListContainer}}*{{/isListContainer}}successPayload, {{/returnType}}NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return {{#returnType}}{{#isListContainer}}*{{/isListContainer}}successPayload, {{/returnType}}localVarAPIResponse, err
 	}
 {{#returnType}}
-	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload){{/returnType}}
-	return {{#returnType}}{{#isListContainer}}*{{/isListContainer}}successPayload, {{/returnType}}NewAPIResponse(localVarHttpResponse.RawResponse), err
+	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
+{{/returnType}}
+	return {{#returnType}}{{#isListContainer}}*{{/isListContainer}}successPayload, {{/returnType}}localVarAPIResponse, err
 }
 {{/operation}}{{/operations}}
diff --git a/modules/swagger-codegen/src/main/resources/go/api_response.mustache b/modules/swagger-codegen/src/main/resources/go/api_response.mustache
index 9bacc9578e4..00ab14a5124 100644
--- a/modules/swagger-codegen/src/main/resources/go/api_response.mustache
+++ b/modules/swagger-codegen/src/main/resources/go/api_response.mustache
@@ -6,8 +6,20 @@ import (
 )
 
 type APIResponse struct {
-	*http.Response
+	*http.Response `json:"-"`
 	Message string `json:"message,omitempty"`
+	// Operation is the name of the swagger operation.
+	Operation       string `json:"operation,omitempty"`
+	// RequestURL is the request URL. This value is always available, even if the
+	// embedded *http.Response is nil.
+	RequestURL      string `json:"url,omitempty"`
+	// Method is the HTTP method used for the request.  This value is always
+	// available, even if the embedded *http.Response is nil.
+	Method          string `json:"method,omitempty"`
+	// Payload holds the contents of the response body (which may be nil or empty).
+	// This is provided here as the raw response.Body() reader will have already
+	// been drained.
+	Payload []byte `json:"-"`
 }
 
 func NewAPIResponse(r *http.Response) *APIResponse {
diff --git a/samples/client/petstore/go/go-petstore/api_response.go b/samples/client/petstore/go/go-petstore/api_response.go
index 0647a0d6b4d..2459f617a03 100644
--- a/samples/client/petstore/go/go-petstore/api_response.go
+++ b/samples/client/petstore/go/go-petstore/api_response.go
@@ -27,8 +27,20 @@ import (
 )
 
 type APIResponse struct {
-	*http.Response
+	*http.Response `json:"-"`
 	Message string `json:"message,omitempty"`
+	// Operation is the name of the swagger operation.
+	Operation       string `json:"operation,omitempty"`
+	// RequestURL is the request URL. This value is always available, even if the
+	// embedded *http.Response is nil.
+	RequestURL      string `json:"url,omitempty"`
+	// Method is the HTTP method used for the request.  This value is always
+	// available, even if the embedded *http.Response is nil.
+	Method          string `json:"method,omitempty"`
+	// Payload holds the contents of the response body (which may be nil or empty).
+	// This is provided here as the raw response.Body() reader will have already
+	// been drained.
+	Payload []byte `json:"-"`
 }
 
 func NewAPIResponse(r *http.Response) *APIResponse {
diff --git a/samples/client/petstore/go/go-petstore/fake_api.go b/samples/client/petstore/go/go-petstore/fake_api.go
index 5de90a7753a..b397726cee6 100644
--- a/samples/client/petstore/go/go-petstore/fake_api.go
+++ b/samples/client/petstore/go/go-petstore/fake_api.go
@@ -24,6 +24,7 @@ package petstore
 
 import (
 	"net/url"
+	"strings"
 	"time"
 	"encoding/json"
 )
@@ -56,7 +57,7 @@ func NewFakeApiWithBasePath(basePath string) *FakeApi {
  */
 func (a FakeApi) TestClientModel(body Client) (*Client, *APIResponse, error) {
 
-	var localVarHttpMethod = "Patch"
+	var localVarHttpMethod = strings.ToUpper("Patch")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/fake"
 
@@ -71,9 +72,8 @@ func (a FakeApi) TestClientModel(body Client) (*Client, *APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
-	localVarHttpContentTypes := []string{ "application/json",  }
+	localVarHttpContentTypes := []string{ "application/json" }
 
 	// set Content-Type header
 	localVarHttpContentType := a.Configuration.APIClient.SelectHeaderContentType(localVarHttpContentTypes)
@@ -82,8 +82,8 @@ func (a FakeApi) TestClientModel(body Client) (*Client, *APIResponse, error) {
 	}
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
-		"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -92,14 +92,22 @@ func (a FakeApi) TestClientModel(body Client) (*Client, *APIResponse, error) {
 	}
 	// body params
 	localVarPostBody = &body
-
 	var successPayload = new(Client)
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "TestClientModel", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return successPayload, localVarAPIResponse, err
 	}
 	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
-	return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+	return successPayload, localVarAPIResponse, err
 }
 
 /**
@@ -123,7 +131,7 @@ func (a FakeApi) TestClientModel(body Client) (*Client, *APIResponse, error) {
  */
 func (a FakeApi) TestEndpointParameters(number float32, double float64, patternWithoutDelimiter string, byte_ string, integer int32, int32_ int32, int64_ int64, float float32, string_ string, binary string, date time.Time, dateTime time.Time, password string) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Post"
+	var localVarHttpMethod = strings.ToUpper("Post")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/fake"
 
@@ -143,9 +151,8 @@ func (a FakeApi) TestEndpointParameters(number float32, double float64, patternW
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
-	localVarHttpContentTypes := []string{ "application/xml; charset=utf-8", "application/json; charset=utf-8",  }
+	localVarHttpContentTypes := []string{ "application/xml; charset=utf-8", "application/json; charset=utf-8" }
 
 	// set Content-Type header
 	localVarHttpContentType := a.Configuration.APIClient.SelectHeaderContentType(localVarHttpContentTypes)
@@ -155,8 +162,8 @@ func (a FakeApi) TestEndpointParameters(number float32, double float64, patternW
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml; charset=utf-8",
-"application/json; charset=utf-8",
-	}
+		"application/json; charset=utf-8"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -176,14 +183,20 @@ func (a FakeApi) TestEndpointParameters(number float32, double float64, patternW
 	localVarFormParams["date"] = a.Configuration.APIClient.ParameterToString(date, "")
 	localVarFormParams["dateTime"] = a.Configuration.APIClient.ParameterToString(dateTime, "")
 	localVarFormParams["password"] = a.Configuration.APIClient.ParameterToString(password, "")
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "TestEndpointParameters", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -201,7 +214,7 @@ func (a FakeApi) TestEndpointParameters(number float32, double float64, patternW
  */
 func (a FakeApi) TestEnumParameters(enumFormStringArray []string, enumFormString string, enumHeaderStringArray []string, enumHeaderString string, enumQueryStringArray []string, enumQueryString string, enumQueryInteger float32, enumQueryDouble float64) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Get"
+	var localVarHttpMethod = strings.ToUpper("Get")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/fake"
 
@@ -223,12 +236,11 @@ func (a FakeApi) TestEnumParameters(enumFormStringArray []string, enumFormString
 	} else {
 		localVarQueryParams.Add("enum_query_string_array", a.Configuration.APIClient.ParameterToString(enumQueryStringArray, collectionFormat))
 	}
-			localVarQueryParams.Add("enum_query_string", a.Configuration.APIClient.ParameterToString(enumQueryString, ""))
-			localVarQueryParams.Add("enum_query_integer", a.Configuration.APIClient.ParameterToString(enumQueryInteger, ""))
-	
+		localVarQueryParams.Add("enum_query_string", a.Configuration.APIClient.ParameterToString(enumQueryString, ""))
+		localVarQueryParams.Add("enum_query_integer", a.Configuration.APIClient.ParameterToString(enumQueryInteger, ""))
 
 	// to determine the Content-Type header
-	localVarHttpContentTypes := []string{ "application/json",  }
+	localVarHttpContentTypes := []string{ "application/json" }
 
 	// set Content-Type header
 	localVarHttpContentType := a.Configuration.APIClient.SelectHeaderContentType(localVarHttpContentTypes)
@@ -237,30 +249,34 @@ func (a FakeApi) TestEnumParameters(enumFormStringArray []string, enumFormString
 	}
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
-		"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
 	// header params "enum_header_string_array"
 	localVarHeaderParams["enum_header_string_array"] = a.Configuration.APIClient.ParameterToString(enumHeaderStringArray, "")
 	// header params "enum_header_string"
 	localVarHeaderParams["enum_header_string"] = a.Configuration.APIClient.ParameterToString(enumHeaderString, "")
-
 	localVarFormParams["enumFormStringArray"] = a.Configuration.APIClient.ParameterToString(enumFormStringArray, "")
 	localVarFormParams["enumFormString"] = a.Configuration.APIClient.ParameterToString(enumFormString, "")
 	localVarFormParams["enumQueryDouble"] = a.Configuration.APIClient.ParameterToString(enumQueryDouble, "")
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "TestEnumParameters", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
diff --git a/samples/client/petstore/go/go-petstore/pet_api.go b/samples/client/petstore/go/go-petstore/pet_api.go
index 04cc352d2bb..093a54342e4 100644
--- a/samples/client/petstore/go/go-petstore/pet_api.go
+++ b/samples/client/petstore/go/go-petstore/pet_api.go
@@ -24,11 +24,11 @@ package petstore
 
 import (
 	"net/url"
+	"strings"
 	"os"
 	"io/ioutil"
 	"encoding/json"
 	"fmt"
-	"strings"
 )
 
 type PetApi struct {
@@ -60,7 +60,7 @@ func NewPetApiWithBasePath(basePath string) *PetApi {
  */
 func (a PetApi) AddPet(body Pet) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Post"
+	var localVarHttpMethod = strings.ToUpper("Post")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/pet"
 
@@ -80,9 +80,8 @@ func (a PetApi) AddPet(body Pet) (*APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
-	localVarHttpContentTypes := []string{ "application/json", "application/xml",  }
+	localVarHttpContentTypes := []string{ "application/json", "application/xml" }
 
 	// set Content-Type header
 	localVarHttpContentType := a.Configuration.APIClient.SelectHeaderContentType(localVarHttpContentTypes)
@@ -92,8 +91,8 @@ func (a PetApi) AddPet(body Pet) (*APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -102,14 +101,20 @@ func (a PetApi) AddPet(body Pet) (*APIResponse, error) {
 	}
 	// body params
 	localVarPostBody = &body
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "AddPet", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -122,7 +127,7 @@ func (a PetApi) AddPet(body Pet) (*APIResponse, error) {
  */
 func (a PetApi) DeletePet(petId int64, apiKey string) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Delete"
+	var localVarHttpMethod = strings.ToUpper("Delete")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/pet/{petId}"
 	localVarPath = strings.Replace(localVarPath, "{"+"petId"+"}", fmt.Sprintf("%v", petId), -1)
@@ -143,7 +148,6 @@ func (a PetApi) DeletePet(petId int64, apiKey string) (*APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -155,26 +159,30 @@ func (a PetApi) DeletePet(petId int64, apiKey string) (*APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
 	// header params "api_key"
 	localVarHeaderParams["api_key"] = a.Configuration.APIClient.ParameterToString(apiKey, "")
-
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "DeletePet", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -186,7 +194,7 @@ func (a PetApi) DeletePet(petId int64, apiKey string) (*APIResponse, error) {
  */
 func (a PetApi) FindPetsByStatus(status []string) ([]Pet, *APIResponse, error) {
 
-	var localVarHttpMethod = "Get"
+	var localVarHttpMethod = strings.ToUpper("Get")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/pet/findByStatus"
 
@@ -213,7 +221,6 @@ func (a PetApi) FindPetsByStatus(status []string) ([]Pet, *APIResponse, error) {
 	} else {
 		localVarQueryParams.Add("status", a.Configuration.APIClient.ParameterToString(status, collectionFormat))
 	}
-	
 
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
@@ -226,22 +233,30 @@ func (a PetApi) FindPetsByStatus(status []string) ([]Pet, *APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
 	var successPayload = new([]Pet)
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "FindPetsByStatus", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return *successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return *successPayload, localVarAPIResponse, err
 	}
 	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
-	return *successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+	return *successPayload, localVarAPIResponse, err
 }
 
 /**
@@ -253,7 +268,7 @@ func (a PetApi) FindPetsByStatus(status []string) ([]Pet, *APIResponse, error) {
  */
 func (a PetApi) FindPetsByTags(tags []string) ([]Pet, *APIResponse, error) {
 
-	var localVarHttpMethod = "Get"
+	var localVarHttpMethod = strings.ToUpper("Get")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/pet/findByTags"
 
@@ -280,7 +295,6 @@ func (a PetApi) FindPetsByTags(tags []string) ([]Pet, *APIResponse, error) {
 	} else {
 		localVarQueryParams.Add("tags", a.Configuration.APIClient.ParameterToString(tags, collectionFormat))
 	}
-	
 
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
@@ -293,22 +307,30 @@ func (a PetApi) FindPetsByTags(tags []string) ([]Pet, *APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
 	var successPayload = new([]Pet)
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "FindPetsByTags", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return *successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return *successPayload, localVarAPIResponse, err
 	}
 	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
-	return *successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+	return *successPayload, localVarAPIResponse, err
 }
 
 /**
@@ -320,7 +342,7 @@ func (a PetApi) FindPetsByTags(tags []string) ([]Pet, *APIResponse, error) {
  */
 func (a PetApi) GetPetById(petId int64) (*Pet, *APIResponse, error) {
 
-	var localVarHttpMethod = "Get"
+	var localVarHttpMethod = strings.ToUpper("Get")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/pet/{petId}"
 	localVarPath = strings.Replace(localVarPath, "{"+"petId"+"}", fmt.Sprintf("%v", petId), -1)
@@ -339,7 +361,6 @@ func (a PetApi) GetPetById(petId int64) (*Pet, *APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -351,22 +372,30 @@ func (a PetApi) GetPetById(petId int64) (*Pet, *APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
 	var successPayload = new(Pet)
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "GetPetById", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return successPayload, localVarAPIResponse, err
 	}
 	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
-	return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+	return successPayload, localVarAPIResponse, err
 }
 
 /**
@@ -378,7 +407,7 @@ func (a PetApi) GetPetById(petId int64) (*Pet, *APIResponse, error) {
  */
 func (a PetApi) UpdatePet(body Pet) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Put"
+	var localVarHttpMethod = strings.ToUpper("Put")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/pet"
 
@@ -398,9 +427,8 @@ func (a PetApi) UpdatePet(body Pet) (*APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
-	localVarHttpContentTypes := []string{ "application/json", "application/xml",  }
+	localVarHttpContentTypes := []string{ "application/json", "application/xml" }
 
 	// set Content-Type header
 	localVarHttpContentType := a.Configuration.APIClient.SelectHeaderContentType(localVarHttpContentTypes)
@@ -410,8 +438,8 @@ func (a PetApi) UpdatePet(body Pet) (*APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -420,14 +448,20 @@ func (a PetApi) UpdatePet(body Pet) (*APIResponse, error) {
 	}
 	// body params
 	localVarPostBody = &body
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "UpdatePet", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -441,7 +475,7 @@ func (a PetApi) UpdatePet(body Pet) (*APIResponse, error) {
  */
 func (a PetApi) UpdatePetWithForm(petId int64, name string, status string) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Post"
+	var localVarHttpMethod = strings.ToUpper("Post")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/pet/{petId}"
 	localVarPath = strings.Replace(localVarPath, "{"+"petId"+"}", fmt.Sprintf("%v", petId), -1)
@@ -462,9 +496,8 @@ func (a PetApi) UpdatePetWithForm(petId int64, name string, status string) (*API
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
-	localVarHttpContentTypes := []string{ "application/x-www-form-urlencoded",  }
+	localVarHttpContentTypes := []string{ "application/x-www-form-urlencoded" }
 
 	// set Content-Type header
 	localVarHttpContentType := a.Configuration.APIClient.SelectHeaderContentType(localVarHttpContentTypes)
@@ -474,8 +507,8 @@ func (a PetApi) UpdatePetWithForm(petId int64, name string, status string) (*API
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -484,14 +517,20 @@ func (a PetApi) UpdatePetWithForm(petId int64, name string, status string) (*API
 	}
 	localVarFormParams["name"] = a.Configuration.APIClient.ParameterToString(name, "")
 	localVarFormParams["status"] = a.Configuration.APIClient.ParameterToString(status, "")
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "UpdatePetWithForm", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -505,7 +544,7 @@ func (a PetApi) UpdatePetWithForm(petId int64, name string, status string) (*API
  */
 func (a PetApi) UploadFile(petId int64, additionalMetadata string, file *os.File) (*ModelApiResponse, *APIResponse, error) {
 
-	var localVarHttpMethod = "Post"
+	var localVarHttpMethod = strings.ToUpper("Post")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/pet/{petId}/uploadImage"
 	localVarPath = strings.Replace(localVarPath, "{"+"petId"+"}", fmt.Sprintf("%v", petId), -1)
@@ -526,9 +565,8 @@ func (a PetApi) UploadFile(petId int64, additionalMetadata string, file *os.File
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
-	localVarHttpContentTypes := []string{ "multipart/form-data",  }
+	localVarHttpContentTypes := []string{ "multipart/form-data" }
 
 	// set Content-Type header
 	localVarHttpContentType := a.Configuration.APIClient.SelectHeaderContentType(localVarHttpContentTypes)
@@ -537,8 +575,8 @@ func (a PetApi) UploadFile(petId int64, additionalMetadata string, file *os.File
 	}
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
-		"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -549,13 +587,21 @@ func (a PetApi) UploadFile(petId int64, additionalMetadata string, file *os.File
 	fbs, _ := ioutil.ReadAll(file)
 	localVarFileBytes = fbs
 	localVarFileName = file.Name()
-
 	var successPayload = new(ModelApiResponse)
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "UploadFile", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return successPayload, localVarAPIResponse, err
 	}
 	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
-	return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+	return successPayload, localVarAPIResponse, err
 }
 
diff --git a/samples/client/petstore/go/go-petstore/store_api.go b/samples/client/petstore/go/go-petstore/store_api.go
index 898dc59d264..97c82b5f91c 100644
--- a/samples/client/petstore/go/go-petstore/store_api.go
+++ b/samples/client/petstore/go/go-petstore/store_api.go
@@ -24,9 +24,9 @@ package petstore
 
 import (
 	"net/url"
+	"strings"
 	"encoding/json"
 	"fmt"
-	"strings"
 )
 
 type StoreApi struct {
@@ -58,7 +58,7 @@ func NewStoreApiWithBasePath(basePath string) *StoreApi {
  */
 func (a StoreApi) DeleteOrder(orderId string) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Delete"
+	var localVarHttpMethod = strings.ToUpper("Delete")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/store/order/{orderId}"
 	localVarPath = strings.Replace(localVarPath, "{"+"orderId"+"}", fmt.Sprintf("%v", orderId), -1)
@@ -74,7 +74,6 @@ func (a StoreApi) DeleteOrder(orderId string) (*APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -86,22 +85,28 @@ func (a StoreApi) DeleteOrder(orderId string) (*APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "DeleteOrder", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -112,7 +117,7 @@ func (a StoreApi) DeleteOrder(orderId string) (*APIResponse, error) {
  */
 func (a StoreApi) GetInventory() (*map[string]int32, *APIResponse, error) {
 
-	var localVarHttpMethod = "Get"
+	var localVarHttpMethod = strings.ToUpper("Get")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/store/inventory"
 
@@ -130,7 +135,6 @@ func (a StoreApi) GetInventory() (*map[string]int32, *APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -141,22 +145,30 @@ func (a StoreApi) GetInventory() (*map[string]int32, *APIResponse, error) {
 	}
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
-		"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
 	var successPayload = new(map[string]int32)
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "GetInventory", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return successPayload, localVarAPIResponse, err
 	}
 	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
-	return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+	return successPayload, localVarAPIResponse, err
 }
 
 /**
@@ -168,7 +180,7 @@ func (a StoreApi) GetInventory() (*map[string]int32, *APIResponse, error) {
  */
 func (a StoreApi) GetOrderById(orderId int64) (*Order, *APIResponse, error) {
 
-	var localVarHttpMethod = "Get"
+	var localVarHttpMethod = strings.ToUpper("Get")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/store/order/{orderId}"
 	localVarPath = strings.Replace(localVarPath, "{"+"orderId"+"}", fmt.Sprintf("%v", orderId), -1)
@@ -184,7 +196,6 @@ func (a StoreApi) GetOrderById(orderId int64) (*Order, *APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -196,22 +207,30 @@ func (a StoreApi) GetOrderById(orderId int64) (*Order, *APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
 	var successPayload = new(Order)
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "GetOrderById", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return successPayload, localVarAPIResponse, err
 	}
 	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
-	return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+	return successPayload, localVarAPIResponse, err
 }
 
 /**
@@ -223,7 +242,7 @@ func (a StoreApi) GetOrderById(orderId int64) (*Order, *APIResponse, error) {
  */
 func (a StoreApi) PlaceOrder(body Order) (*Order, *APIResponse, error) {
 
-	var localVarHttpMethod = "Post"
+	var localVarHttpMethod = strings.ToUpper("Post")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/store/order"
 
@@ -238,7 +257,6 @@ func (a StoreApi) PlaceOrder(body Order) (*Order, *APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -250,8 +268,8 @@ func (a StoreApi) PlaceOrder(body Order) (*Order, *APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -260,13 +278,21 @@ func (a StoreApi) PlaceOrder(body Order) (*Order, *APIResponse, error) {
 	}
 	// body params
 	localVarPostBody = &body
-
 	var successPayload = new(Order)
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "PlaceOrder", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return successPayload, localVarAPIResponse, err
 	}
 	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
-	return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+	return successPayload, localVarAPIResponse, err
 }
 
diff --git a/samples/client/petstore/go/go-petstore/user_api.go b/samples/client/petstore/go/go-petstore/user_api.go
index 262312d986a..5229e079366 100644
--- a/samples/client/petstore/go/go-petstore/user_api.go
+++ b/samples/client/petstore/go/go-petstore/user_api.go
@@ -24,9 +24,9 @@ package petstore
 
 import (
 	"net/url"
+	"strings"
 	"encoding/json"
 	"fmt"
-	"strings"
 )
 
 type UserApi struct {
@@ -58,7 +58,7 @@ func NewUserApiWithBasePath(basePath string) *UserApi {
  */
 func (a UserApi) CreateUser(body User) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Post"
+	var localVarHttpMethod = strings.ToUpper("Post")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/user"
 
@@ -73,7 +73,6 @@ func (a UserApi) CreateUser(body User) (*APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -85,8 +84,8 @@ func (a UserApi) CreateUser(body User) (*APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -95,14 +94,20 @@ func (a UserApi) CreateUser(body User) (*APIResponse, error) {
 	}
 	// body params
 	localVarPostBody = &body
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "CreateUser", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -114,7 +119,7 @@ func (a UserApi) CreateUser(body User) (*APIResponse, error) {
  */
 func (a UserApi) CreateUsersWithArrayInput(body []User) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Post"
+	var localVarHttpMethod = strings.ToUpper("Post")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/user/createWithArray"
 
@@ -129,7 +134,6 @@ func (a UserApi) CreateUsersWithArrayInput(body []User) (*APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -141,8 +145,8 @@ func (a UserApi) CreateUsersWithArrayInput(body []User) (*APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -151,14 +155,20 @@ func (a UserApi) CreateUsersWithArrayInput(body []User) (*APIResponse, error) {
 	}
 	// body params
 	localVarPostBody = &body
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "CreateUsersWithArrayInput", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -170,7 +180,7 @@ func (a UserApi) CreateUsersWithArrayInput(body []User) (*APIResponse, error) {
  */
 func (a UserApi) CreateUsersWithListInput(body []User) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Post"
+	var localVarHttpMethod = strings.ToUpper("Post")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/user/createWithList"
 
@@ -185,7 +195,6 @@ func (a UserApi) CreateUsersWithListInput(body []User) (*APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -197,8 +206,8 @@ func (a UserApi) CreateUsersWithListInput(body []User) (*APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -207,14 +216,20 @@ func (a UserApi) CreateUsersWithListInput(body []User) (*APIResponse, error) {
 	}
 	// body params
 	localVarPostBody = &body
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "CreateUsersWithListInput", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -226,7 +241,7 @@ func (a UserApi) CreateUsersWithListInput(body []User) (*APIResponse, error) {
  */
 func (a UserApi) DeleteUser(username string) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Delete"
+	var localVarHttpMethod = strings.ToUpper("Delete")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/user/{username}"
 	localVarPath = strings.Replace(localVarPath, "{"+"username"+"}", fmt.Sprintf("%v", username), -1)
@@ -242,7 +257,6 @@ func (a UserApi) DeleteUser(username string) (*APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -254,22 +268,28 @@ func (a UserApi) DeleteUser(username string) (*APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "DeleteUser", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -281,7 +301,7 @@ func (a UserApi) DeleteUser(username string) (*APIResponse, error) {
  */
 func (a UserApi) GetUserByName(username string) (*User, *APIResponse, error) {
 
-	var localVarHttpMethod = "Get"
+	var localVarHttpMethod = strings.ToUpper("Get")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/user/{username}"
 	localVarPath = strings.Replace(localVarPath, "{"+"username"+"}", fmt.Sprintf("%v", username), -1)
@@ -297,7 +317,6 @@ func (a UserApi) GetUserByName(username string) (*User, *APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -309,22 +328,30 @@ func (a UserApi) GetUserByName(username string) (*User, *APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
 	var successPayload = new(User)
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "GetUserByName", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return successPayload, localVarAPIResponse, err
 	}
 	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
-	return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+	return successPayload, localVarAPIResponse, err
 }
 
 /**
@@ -337,7 +364,7 @@ func (a UserApi) GetUserByName(username string) (*User, *APIResponse, error) {
  */
 func (a UserApi) LoginUser(username string, password string) (*string, *APIResponse, error) {
 
-	var localVarHttpMethod = "Get"
+	var localVarHttpMethod = strings.ToUpper("Get")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/user/login"
 
@@ -352,8 +379,7 @@ func (a UserApi) LoginUser(username string, password string) (*string, *APIRespo
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 		localVarQueryParams.Add("username", a.Configuration.APIClient.ParameterToString(username, ""))
-			localVarQueryParams.Add("password", a.Configuration.APIClient.ParameterToString(password, ""))
-	
+		localVarQueryParams.Add("password", a.Configuration.APIClient.ParameterToString(password, ""))
 
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
@@ -366,22 +392,30 @@ func (a UserApi) LoginUser(username string, password string) (*string, *APIRespo
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
 	var successPayload = new(string)
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "LoginUser", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
+	}
+
 	if err != nil {
-		return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+		return successPayload, localVarAPIResponse, err
 	}
 	err = json.Unmarshal(localVarHttpResponse.Body(), &successPayload)
-	return successPayload, NewAPIResponse(localVarHttpResponse.RawResponse), err
+	return successPayload, localVarAPIResponse, err
 }
 
 /**
@@ -392,7 +426,7 @@ func (a UserApi) LoginUser(username string, password string) (*string, *APIRespo
  */
 func (a UserApi) LogoutUser() (*APIResponse, error) {
 
-	var localVarHttpMethod = "Get"
+	var localVarHttpMethod = strings.ToUpper("Get")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/user/logout"
 
@@ -407,7 +441,6 @@ func (a UserApi) LogoutUser() (*APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -419,22 +452,28 @@ func (a UserApi) LogoutUser() (*APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
 	if localVarHttpHeaderAccept != "" {
 		localVarHeaderParams["Accept"] = localVarHttpHeaderAccept
 	}
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "LogoutUser", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }
 
 /**
@@ -447,7 +486,7 @@ func (a UserApi) LogoutUser() (*APIResponse, error) {
  */
 func (a UserApi) UpdateUser(username string, body User) (*APIResponse, error) {
 
-	var localVarHttpMethod = "Put"
+	var localVarHttpMethod = strings.ToUpper("Put")
 	// create path and map variables
 	localVarPath := a.Configuration.BasePath + "/user/{username}"
 	localVarPath = strings.Replace(localVarPath, "{"+"username"+"}", fmt.Sprintf("%v", username), -1)
@@ -463,7 +502,6 @@ func (a UserApi) UpdateUser(username string, body User) (*APIResponse, error) {
 		localVarHeaderParams[key] = a.Configuration.DefaultHeader[key]
 	}
 
-
 	// to determine the Content-Type header
 	localVarHttpContentTypes := []string{  }
 
@@ -475,8 +513,8 @@ func (a UserApi) UpdateUser(username string, body User) (*APIResponse, error) {
 	// to determine the Accept header
 	localVarHttpHeaderAccepts := []string{
 		"application/xml",
-"application/json",
-	}
+		"application/json"
+		}
 
 	// set Accept header
 	localVarHttpHeaderAccept := a.Configuration.APIClient.SelectHeaderAccept(localVarHttpHeaderAccepts)
@@ -485,13 +523,19 @@ func (a UserApi) UpdateUser(username string, body User) (*APIResponse, error) {
 	}
 	// body params
 	localVarPostBody = &body
-
-
 	localVarHttpResponse, err := a.Configuration.APIClient.CallAPI(localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
-	if err != nil {
-		return NewAPIResponse(localVarHttpResponse.RawResponse), err
+
+	var localVarURL, _ = url.Parse(localVarPath)
+	localVarURL.RawQuery = localVarQueryParams.Encode()
+	var localVarAPIResponse = &APIResponse{Operation: "UpdateUser", Method: localVarHttpMethod, RequestURL: localVarURL.String()}
+	if localVarHttpResponse != nil {
+		localVarAPIResponse.Response = localVarHttpResponse.RawResponse
+		localVarAPIResponse.Payload = localVarHttpResponse.Body()
 	}
 
-	return NewAPIResponse(localVarHttpResponse.RawResponse), err
+	if err != nil {
+		return localVarAPIResponse, err
+	}
+	return localVarAPIResponse, err
 }