You need an API for creating events?

Yes, I would piggyback on to the base event which would be created, which would allow me to build out my extra features which need a base event.

API's are always a good thing, weather they are private or not.

Not the person who asked for it, but I think they were suggesting they'd use the API to retrieve information about RSVPs/current state of a planned event. (Perhaps even RSVP on someone else's behalf.)