Customize Facebook Events app by prompting user action after an RSVP

Is it possible to customize the Facebook Events app and hook in a user call-to-action after someone RSVPs?

Our goal is not to create a new app, but to leverage the existing Events app and layer on one bit of functionality. Specifically, after someone RSVPs, we want to show a link for them to click on.

Is this possible?

Thanks!

The easiest way to do this would be to check if a given user ID is found in the attending connection of the Graph API Event edge. You wouldn't be able to do this in an event page since that is solely controlled by facebook, but if your app is managing events for users, then this is possible by pulling the attending edge of the Event in question.