@@ -5,63 +5,91 @@ "fmt"
 	"net/http"
 )
 
-type Error struct {
-	Code    int
-	Message string
-	Cause   error
+type Error interface {
+	error
+	StatusCode() int
+	Message() string
+	Unwrap() error
+	WriteHTTP(w http.ResponseWriter)
 }
 
-func (e *Error) Error() string {
-	if e.Message == "" {
-		e.Message = http.StatusText(e.Code)
+type httpError struct {
+	code    int
+	message string
+	cause   error
+}
+
+func (e *httpError) Error() string {
+	if e.message == "" {
+		e.message = http.StatusText(e.code)
 	}
 
-	return fmt.Sprintf("%d %s", e.Code, e.Message)
+	return fmt.Sprintf("%d %s", e.code, e.message)
+}
+
+func (e *httpError) StatusCode() int {
+	return e.code
 }
 
-func NewError(code int, message string, cause error) *Error {
-	return &Error{
-		Code:    code,
-		Message: message,
-		Cause:   cause,
+func (e *httpError) Message() string {
+	if e.message == "" {
+		e.message = http.StatusText(e.code)
 	}
+
+	return e.message
 }
 
-func NotFound(message string) *Error {
-	return &Error{
-		Code:    http.StatusNotFound,
-		Message: message,
+func (e *httpError) Unwrap() error {
+	return e.cause
+}
+
+func (e *httpError) WriteHTTP(w http.ResponseWriter) {
+	http.Error(w, e.message, e.code)
+}
+
+func NewError(code int, message string, cause error) Error {
+	return &httpError{
+		code:    code,
+		message: message,
+		cause:   cause,
 	}
 }
 
-func BadRequest(message string, cause error) *Error {
-	return &Error{
-		Code:    http.StatusBadRequest,
-		Message: message,
-		Cause:   cause,
+func NotFound(message string) Error {
+	return &httpError{
+		code:    http.StatusNotFound,
+		message: message,
 	}
 }
 
-func InternalServerError(message string, cause error) *Error {
-	return &Error{
-		Code:    http.StatusInternalServerError,
-		Message: message,
-		Cause:   cause,
+func BadRequest(message string, cause error) Error {
+	return &httpError{
+		code:    http.StatusBadRequest,
+		message: message,
+		cause:   cause,
+	}
+}
+
+func InternalServerError(message string, cause error) Error {
+	return &httpError{
+		code:    http.StatusInternalServerError,
+		message: message,
+		cause:   cause,
 	}
 }
 
-func Unauthorized(message string, cause error) *Error {
-	return &Error{
-		Code:    http.StatusUnauthorized,
-		Message: message,
-		Cause:   cause,
+func Unauthorized(message string, cause error) Error {
+	return &httpError{
+		code:    http.StatusUnauthorized,
+		message: message,
+		cause:   cause,
 	}
 }
 
-func Forbidden(message string, cause error) *Error {
-	return &Error{
-		Code:    http.StatusForbidden,
-		Message: message,
-		Cause:   cause,
+func Forbidden(message string, cause error) Error {
+	return &httpError{
+		code:    http.StatusForbidden,
+		message: message,
+		cause:   cause,
 	}
 }