Android: How to package and deploy AIDL interfaces?

Can raw AIDL files go in the jar files

Well, they can, they just won't do anyone any good automatically.

do must they be first compiled into stubs?

That is one possibility. I think it's safer if you would ship the AIDL file and tell them were to place it in their project.

I think the Android library project stuff now supports AIDL files, but I am not 100% certain. If it does, you could package your stuff as an Android library project, and the AIDL will be picked up automatically.