title: Identifying Facebook Messenger user with UserID from a Facebook Login
body: <p>I am trying out the new Facebook Messenger Platform and have hit a bit of a problem.</p>
  
  <p>When a user first chats with my Bot, I want to use the <code>sender.id</code> to lookup the user in my DB and verify whether they're a customer or not and offer a more tailored UX.</p>
  
  <p>User's sign up to my service using Facebook Login, but unfortunately it appears my App's Facebook ID &amp; my Bot's Facebook ID are different due to IDs being limited to App-scopes.</p>
  
  <p><strong>Is there any way associate the 2 IDs to allow me to find a user in my DB?</strong></p>
  
  <p><strong>UPDATE (4/20/2016):</strong>
  We got around this by asking users on first contact via messenger to click a link to login to their account so we could associate their messenger_id with their account in our DB.</p>
  
  <p>Would be awesome if facebook instead included PAGE_SCOPED IDs in the <code>ids_for_business</code> endpoint.</p>
  
  <p><strong>UPDATE: (6/1/2016):</strong>
  Facebook's latest update includes a new "Account Linking" functionality that appears to solve this issue. See <a href="https://developers.facebook.com/docs/messenger-platform/account-linking">https://developers.facebook.com/docs/messenger-platform/account-linking</a></p>