diff -r 5d803adfc57e -r 6ec2a44a1bd1 gondole.go
--- a/gondole.go	Thu Apr 13 00:17:57 2017 +0200
+++ b/gondole.go	Thu Apr 13 09:30:47 2017 +0200
@@ -19,8 +19,10 @@
 	NoRedirect = "urn:ietf:wg:oauth:2.0:oob"
 )
 
+// Error codes
 var (
-	ErrAlreadyRegistered = errors.New("App already registered")
+	ErrAlreadyRegistered = errors.New("app already registered")
+	ErrEntityNotFound    = errors.New("entity not found")
 )
 
 // prepareRequest insert all pre-defined stuff