title: Facebook GraphAPIError: (#4) Application request limit reached - on first request
body: <p>I'm building a new app which is still in development, i.e., I am the only user. The user is authenticated on the frontend, which then passes a Facebook access token to the backend. I want to validate this token on the backend to make sure that it's still valid, that it matches this application, and that the user matches. As described in <a href="https://stackoverflow.com/questions/8605703/how-to-verify-facebook-access-token/8608017#8608017">how to verify facebook access token?</a> (and <a href="https://developers.facebook.com/docs/facebook-login/access-tokens#debug" rel="nofollow noreferrer">the official Facebook docs</a>), this can be done by calling <code>graph.facebook.com/debug_token</code>.</p>
  
  <p>When I make this call from my local machine, it works fine.  When I do it using the <a href="https://developers.facebook.com/tools/explorer/145634995501895/?session_id=1493470534297768" rel="nofollow noreferrer">Graph API Explorer</a> debug tool, it works fine.  It used to work fine from my backend, too, but a few days ago it stopped working and now I get this error every time I make this call:</p>
  
  <p><code>GraphAPIError: (#4) Application request limit reached</code></p>
  
  <p>I could not possibly have exceeded any limits since the total number of API calls is tiny (this app is still in development mode, and I'm making a single call per login, not batching anything, not trying to read a feed, etc.). In fact, the very first request I make on a given day causes this error. Here's Facebook's graph of the total number of API calls I'm making:</p>
  
  <p><a href="https://i.stack.imgur.com/awV8g.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/awV8g.png" alt="Facebook API Usage and Performance"></a></p>
  
  <p>There are a number of questions about the same error e.g. <a href="https://stackoverflow.com/questions/9272391/facebook-application-request-limit-reached">Facebook Application Request limit reached</a>, however in all of these cases, it appears that users were actually exceeding some request limit, whereas in this case, that doesn't seem possible. The error seems misleading.</p>
  
  <p>My backend is written in Python and hosted on Google App Engine.</p>
  
  <p>Any ideas what may be causing this?</p>