If anyone wants to use Google Oauth2 with flask and User session management we have Open sourced the project: <a href="https://github.com/GrexIt/flask-login-oauth2" rel="nofollow">https://github.com/GrexIt/flask-login-oauth2</a>
I wish that for OAuth 3 they would make it such that client and server can separately sign the request and you don't have to share keys between the two. That would be a great security enhancement.
And yet, here we are, with OAuth still a complex behemoth and everyone doing login with Facebook, Twitter, or a poorly-implemented homegrown login system.