24-03-2013, 10:07 AM
Facebook new threaded chat similar to that in mobile SMSFacebook is in the process of making the new messages system available to all users, at which point this API will replace the /inbox/ Graph API endpoint. It is providing early access to this API for registered developer accounts only until the new messaging system is broadly available. You should use the /inbox endpoint for production applications at the current time.
Screenshots is as follows: