diff --git a/api/error.go b/api/error.go
index eaf32b7..dcc6ecb 100644
--- a/api/error.go
+++ b/api/error.go
@@ -13,26 +13,21 @@ type Error struct {
 	Arguments []interface{} `json:"arguments"`
 }
 
-// WrapError returns a new error from a base error with errorarguments.
-func WrapError(baseError Error, arguments ...interface{}) Error {
-	for _, arg := range arguments {
-		baseError.Put(arg)
-	}
-	return baseError
-}
-
-// Put adds an argument to the error
+// SetArguments set one or multiple arguments to the error
 // to be displayed back to API caller
-func (e *Error) Put(arg interface{}) {
+func (e *Error) SetArguments(arg0 interface{}, args ...interface{}) {
 
-	/* (1) Make slice if not */
-	if e.Arguments == nil {
-		e.Arguments = make([]interface{}, 0)
+	// 1. clear arguments */
+	e.Arguments = make([]interface{}, 0)
+
+	// 2. add arg[0]
+	e.Arguments = append(e.Arguments, arg0)
+
+	// 3. add optional other arguments
+	for _, arg := range args {
+		e.Arguments = append(e.Arguments, arg)
 	}
 
-	/* (2) Append argument */
-	e.Arguments = append(e.Arguments, arg)
-
 }
 
 // Implements 'error'
diff --git a/api/response.go b/api/response.go
index 2ea4e6f..d8bd700 100644
--- a/api/response.go
+++ b/api/response.go
@@ -33,38 +33,46 @@ func NewResponse(errors ...Error) *Response {
 	return res
 }
 
+// WrapError sets the error from a base error with error arguments.
+func (res *Response) WrapError(baseError Error, arguments ...interface{}) {
+	if len(arguments) > 0 {
+		baseError.SetArguments(arguments[0], arguments[1:])
+	}
+	res.Err = baseError
+}
+
 // SetData adds/overrides a new response field
-func (i *Response) SetData(name string, value interface{}) {
-	i.Data[name] = value
+func (res *Response) SetData(name string, value interface{}) {
+	res.Data[name] = value
 }
 
 // GetData gets a response field
-func (i *Response) GetData(name string) interface{} {
-	value, _ := i.Data[name]
+func (res *Response) GetData(name string) interface{} {
+	value, _ := res.Data[name]
 
 	return value
 }
 
 // MarshalJSON implements the 'json.Marshaler' interface and is used
 // to generate the JSON representation of the response
-func (i *Response) MarshalJSON() ([]byte, error) {
+func (res *Response) MarshalJSON() ([]byte, error) {
 	fmt := make(map[string]interface{})
 
-	for k, v := range i.Data {
+	for k, v := range res.Data {
 		fmt[k] = v
 	}
 
-	fmt["error"] = i.Err
+	fmt["error"] = res.Err
 
 	return json.Marshal(fmt)
 }
 
 // Write writes to an HTTP response.
-func (i *Response) Write(w http.ResponseWriter) error {
-	w.WriteHeader(i.Status)
+func (res *Response) Write(w http.ResponseWriter) error {
+	w.WriteHeader(res.Status)
 	w.Header().Add("Content-Type", "application/json")
 
-	fmt, err := json.Marshal(i)
+	fmt, err := json.Marshal(res)
 	if err != nil {
 		return err
 	}
diff --git a/server.go b/server.go
index b3d4d42..6964f60 100644
--- a/server.go
+++ b/server.go
@@ -112,13 +112,15 @@ func (s *Server) ServeHTTP(res http.ResponseWriter, req *http.Request) {
 	// fail if found no handler
 	if serviceHandler == nil {
 		if serviceFound {
-			apiResponse := api.NewResponse(api.WrapError(api.ErrorUncallableMethod(), servicePath, req.Method))
+			apiResponse := api.NewResponse()
+			apiResponse.WrapError(api.ErrorUncallableMethod(), servicePath, req.Method)
 			apiResponse.Write(res)
 			logError(apiResponse)
 			return
 		}
 
-		apiResponse := api.NewResponse(api.WrapError(api.ErrorUncallableService(), servicePath))
+		apiResponse := api.NewResponse()
+		apiResponse.WrapError(api.ErrorUncallableService(), servicePath)
 		apiResponse.Write(res)
 		logError(apiResponse)
 		return
diff --git a/util.go b/util.go
index b027634..2550d1b 100644
--- a/util.go
+++ b/util.go
@@ -23,7 +23,9 @@ func (s *Server) extractParameters(store *reqdata.Store, methodParam map[string]
 
 		// 2. fail if required & missing
 		if !isset && !param.Optional {
-			return nil, api.WrapError(api.ErrorMissingParam(), name)
+			apiErr := api.ErrorMissingParam()
+			apiErr.SetArguments(name)
+			return nil, apiErr
 		}
 
 		// 3. optional & missing: set default value
@@ -50,7 +52,9 @@ func (s *Server) extractParameters(store *reqdata.Store, methodParam map[string]
 		// 5. fail on unexpected multipart file
 		waitFile, gotFile := param.Type == "FILE", p.File
 		if gotFile && !waitFile || !gotFile && waitFile {
-			return nil, api.WrapError(api.ErrorInvalidParam(), param.Rename, "FILE")
+			apiErr := api.ErrorInvalidParam()
+			apiErr.SetArguments(param.Rename, "FILE")
+			return nil, apiErr
 		}
 
 		// 6. do not check if file
@@ -61,7 +65,9 @@ func (s *Server) extractParameters(store *reqdata.Store, methodParam map[string]
 
 		// 7. check type
 		if s.Checkers.Run(param.Type, p.Value) != nil {
-			return nil, api.WrapError(api.ErrorInvalidParam(), param.Rename, param.Type, p.Value)
+			apiErr := api.ErrorInvalidParam()
+			apiErr.SetArguments(param.Rename, param.Type, p.Value)
+			return nil, apiErr
 		}
 
 		parameters[param.Rename] = p.Value