title: Google sign-in on Android - access token
body: <p>I am setting up my app with Google sign in and can't figure how you get the access token.
  We have a front-end app where the user logs in. I then need to send the access token to the back end for user authentication.
  I fetch the user details (name etc) and also get the authentication-token.</p>
  
  <p>I used the code given by Google and the examples from here: <a href="https://github.com/googlesamples/google-services/tree/master/android/signin" rel="nofollow noreferrer">https://github.com/googlesamples/google-services/tree/master/android/signin</a></p>
  
  <p>I got through all the stages but I can't figure where I get the access token to send to the backend for authentication. It says in the docs that the auth token "can be exchanged for an access and refresh token" but I can't for the life of me find out how.</p>
  
  <p>I am a newbie with Google signin so I might be doing it completely wrong.</p>
  
  <p>After posting I found a similar question: <a href="https://stackoverflow.com/questions/33844330/google-login-get-access-token-with-new-googlesigninoptions">Google login get access token with new GoogleSignInOptions</a></p>