Our web application does not offer Google Accounts authentication. We have implemented our own authentication using WebApp2 Authentication: http://webapp-improved.appspot.com/tutorials/auth.html.
We'd like to use Cloud Endpoints as an API for mobile apps/third party developers but we would still like to use oAuth2 for authentication.
What are the steps required to implement this? Do we need to setup our own oAuth server on AppEngine and will the Google client libraries be compatible?