title: How to get the access token from Google Sign-In Javascript SDK?
body: <p>I have a simple single-page javascript webapp which uses "Google Sign-In for Websites": <a href="https://developers.google.com/identity/sign-in/web/sign-in">https://developers.google.com/identity/sign-in/web/sign-in</a></p>
  
  <p>How can I get an access token for the user? I need a verifiable assertion of the user's identity on my server. I don't want offline access; I just want to know that when the web client sends an ajax request to my server, I can trust the identity of the logged-in user.</p>