diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..996352e
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,9 @@
+module github.com/chiuwah/fd_oauth-go
+
+go 1.14
+
+require (
+	github.com/chiuwah/fd_utils-go v0.1.0
+	github.com/federicoleon/golang-restclient v0.0.0-20191104170228-162ed620df66
+	github.com/stretchr/testify v1.5.1 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..bde75ed
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,15 @@
+github.com/chiuwah/fd_utils-go v0.1.0 h1:6yN6HIOESTiiNWY5ZGd4ayS96OdHTxPVXnuM8VLWhPM=
+github.com/chiuwah/fd_utils-go v0.1.0/go.mod h1:6Tbw5hgblKbNyMTeD0fhpmhGbwpm3pQLJ2oRxxa2DuM=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/federicoleon/golang-restclient v0.0.0-20191104170228-162ed620df66 h1:QESWlOIiziWcM4bCvtT7TFg4PXjudKMnO3ArjxuIJj4=
+github.com/federicoleon/golang-restclient v0.0.0-20191104170228-162ed620df66/go.mod h1:lvjF6h5LrES4h39ha/njlBBBqCmISh6BNSEiXH+mT5k=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
+github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/oauth/errors/errors.go b/oauth/errors/errors.go
deleted file mode 100644
index 6289841..0000000
--- a/oauth/errors/errors.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package errors
-
-import (
-	"net/http"
-)
-
-type RestErr struct {
-	Message string `json:"message"`
-	Status  int    `json:"status"`
-	Error   string `json:"error"`
-}
-
-func NewBadRequestError(message string) *RestErr {
-	return &RestErr{
-		Message: message,
-		Status:  http.StatusBadRequest,
-		Error:   "bad_request",
-	}
-}
-
-func NewNotFoundError(message string) *RestErr {
-	return &RestErr{
-		Message: message,
-		Status:  http.StatusNotFound,
-		Error:   "not_found",
-	}
-}
-
-func NewInternalServerError(message string) *RestErr {
-	return &RestErr{
-		Message: message,
-		Status:  http.StatusInternalServerError,
-		Error:   "internal_server_error",
-	}
-}
diff --git a/oauth/oauth.go b/oauth/oauth.go
index f2bc7d2..dafe42b 100644
--- a/oauth/oauth.go
+++ b/oauth/oauth.go
@@ -3,7 +3,7 @@ package oauth
 import (
 	"encoding/json"
 	"fmt"
-	"github.com/chiuwah/fd_oauth-go/oauth/errors"
+	"github.com/chiuwah/fd_utils-go/rest_errors"
 	"github.com/federicoleon/golang-restclient/rest"
 	"net/http"
 	"strconv"
@@ -61,14 +61,14 @@ func GetClientId(request *http.Request) int64 {
 	return clientId
 }
 
-func AuthenticateRequest(request *http.Request) *errors.RestErr {
+func AuthenticateRequest(request *http.Request) *rest_errors.RestErr {
 	if request == nil {
 		return nil
 	}
 
 	cleanRequest(request)
 
-	accessTokenId := strings.TrimSpace(request.URL.Query().Get(paramAccessToken))
+	accessTokenId := strings.TrimSpace(request.URL. Query().Get(paramAccessToken))
 	if accessTokenId == "" {
 		return nil
 	}
@@ -96,22 +96,22 @@ func cleanRequest(request *http.Request) {
 
 }
 
-func getAccessToken(accessTokenId string) (*accessToken, *errors.RestErr) {
+func getAccessToken(accessTokenId string) (*accessToken, *rest_errors.RestErr) {
 	response := oauthRestClient.Get(fmt.Sprintf("/oauth/access_token/%s", accessTokenId))
 
 	if response == nil || response.Response == nil {
-		return nil, errors.NewInternalServerError("invalid restclient response when trying to get access token")
+		return nil, rest_errors.NewInternalServerError("invalid restclient response when trying to get access token", rest_errors.NewError("invalid response"))
 	}
 	if response.StatusCode > 299 {
-		var restErr errors.RestErr
+		var restErr rest_errors.RestErr
 		if err := json.Unmarshal(response.Bytes(), &restErr); err != nil {
-			return nil, errors.NewInternalServerError("invalid error interface when trying to get access token")
+			return nil, rest_errors.NewInternalServerError("invalid error interface when trying to get access token", err)
 		}
 		return nil, &restErr
 	}
 	var at accessToken
 	if err := json.Unmarshal(response.Bytes(), &at); err != nil {
-		return nil, errors.NewInternalServerError("error when trying to unmarshal access token response")
+		return nil, rest_errors.NewInternalServerError("error when trying to unmarshal access token response", err)
 	}
 	return &at, nil
 }