I would really like, for both shared DB repos and API repos:
- The canonical name of the file namespace on that wiki (for constructing URLs)
- The article path on that wiki (for constructing different URLs)
I can't currently think of anything else crucial, but that's life.
I'd also in the future like a small icon that can represent the repository in the media viewer - right now we have a hacked-together icon that screams "not Commons" but still looks like a central repository icon. I'd be really happy to put a Wikipedia logo there if applicable.