I am developing Google App Engine application written in Python and using Endpoints API. In conjunction, I am writing a Chrome Extension to interact with the Endpoints API.
Just in case anyone is here since 1.8.6 and is still trying to use the auth_util.py work around to return the Google profile id. endpoints.token_id now has two methods depending on if the user is on the development server or not.
When on Google's servers the flow returns the oauth_user and does not hit the tokeninfo endpoint. Therefore no token info is saved in auth_util.py. However, on the dev server it does hit the tokeninfo endpoint so works as expected.
For me the easiest way to solve this was just to monkey patch endpoints.token_id._is_local_dev and set that to always be true.