If I'm reading your question right - you'd want some API to fetch the relationshiops
and other metadata
information from the DbContext
or EF/code-first at runtime?
The best I've seen so far - and the best the two of us could do was this...
How I can read EF DbContext metadata programmatically?
...take a look if this can help you...
And you're welcome to post there if you happen to come into possession of some new and vital piece of information (we made it with the intention to serve as a one-stop question for subjects like this).