I have a facebook app that hooks into an external calendar built using PHP and MySQL. Some of the events in this calendar have associated facebook events, some don't. The external calendaring system also supports invitations and responses to events.
When a user is invited to an event on the non-facebook calendar, I would like to be able to send them some sort of facebook notification advising them that there is a new event they need to respond to. Ideally this would just be an entry in the notifications list that pops up in the top right (between the messages popup link and the search box). Failing that, an entry in the feed on their home page would be good but it can't appear anywhere public. I can already post to the user's wall but this means that the invitation would appear to the public and some of these events are private.
The site has been using the old facebook rest api but I have already begun moving things over to the new Graph Api and would prefer to use this if possible as this seems to be the new preferred way of doing things. However I haven't been able to find any way to send any kind of notification with the Graph Api
Any pointers or suggestions would be most welcome