title: How do I authorise an app (web or installed) without user intervention?
body: <p>Let's say that I have a web app (&quot;mydriveapp&quot;) that needs to access Drive files in a background service. It will either own the files it is accessing, or be run in a Google Account with which the owner has shared the documents.</p>
  <p>I understand that my app needs a refresh token, but <strong>I don't want to write the code to obtain that</strong> since I'll only ever do it once.</p>
  <p><strong>NB. This is NOT using a Service Account.</strong> The app will be run under a conventional Google account. Service Account is a valid approach in some situations. However the technique of using Oauth Playground to simulate the app can save a bunch of redundant effort, and applies to any APIs for which sharing to a Service Account is unsupported.</p>