Facebook: Infinite Session Keys

Facebook infinite session keys provide a great way for developers to write external applications and allow them to interface with your Facebook applications.

This is particularly useful when you need to write a batch / cron job that requires access to the Facebook API.

I found the online documentation to be pretty cryptic, so I thought I would document the steps involved to set this up:

1. Generate a one time code by accessing the following URL in a browser: http://www.facebook.com/code_gen.php?v=1.0&api_key=YOUR_API_KEY
   
   
2. Use the generated code instead of the auth_token that is normally passed to the auth.getSession.
   
   
3. The session returned from this call is known as your "Infinite Session Key" and can be used to setup in any external program. e.g.
   
   PHP:
   
   $facebook = new Facebook($api_key, $secret);
   $facebook->set_user($myuid, $infkey);
   
   Java:
   
   FacebookRestClient facebookRestClient = new FacebookRestClient(apiKey, secretKey);
   facebookRestClient.auth_getSession(oneTimeCode); // get infinite session using the one time code
   
   
4. That's it! Your external program should now be able to access the Facebook API just as if it was running inside Facebook.