Once they have this graph, do you offer some other service to read/view it?

Or better yet, Is the graph your API returns in a standardized AI (idk if one exists tbh) or open source graph model (e.g. DAG)?

Kudos for solving this problem if you truly did, best of luck going forward!

I will say i highly doubt most companies will be willing to send you entire source code zips vs a more established company. My advice would be to focus more on the on-prem now instead of a future development effort