I'm working on something similar with https://github.com/dtkav/agent-creds though I keep growing the scope.
The model is solid. It feels like the right way to use YOLO mode.
I've been working on making the auth setup more granular with macaroons and third party caveats.
My dream is to have plugins for upstreams using OpenAPI specs and then make it really easy to stitch together grants across subsets of APIs.
I think there's a product in here somewhere...