title: Google API : How to authenticate without redirection?
body: <p>We want to use Google Doc API to generate Document (In our own business account) when our end users do some actions on our site.</p>
  
  <p>The problem is that we've tried to implement the OAuth 2.0 protocol, as suggested in the v3.0 protocol documentation. The apiClient::authentication method do a redirection. This is a major problem because our users doesn't know the access to our own business account.... and we don't want to give them access anyway ;)</p>
  
  <p>(In other word, we're not creating an application that allow our users to edit their own data, but to interact with our data, like a database.)</p>
  
  <p>I've read that the point of OAuth 2.0 was to avoid that we manage the credential of our users. I'm personally O.K. with the concept, but in our case, we don't want to get authenticated in the google account of our users ...</p>
  
  <p>So, what would be the best approach to get a valid authentication without any interaction from the end user ?</p>