[Feature] Security support with SSO

[sudhanshu746]

Thanks for the great work! I've been working on structured extraction projects and am excited about langchain's open source offerings on this.
I would like to host the Langchain's extraction service with Active directory SSO access (next-auth.js) and API access

I'm happy to contribute with development efforts.

Support for

[eyurtsev]

We'll need to investigate! I personally haven't implemented SSO in the past, so there are a few basic details I don't know -- and would need to try and set up next-auth.js.

• We're not sure yet whether we'll keep next.js vs. swap to vite -- the app is very small so it might be easier to package up the assets and ship them from an endpoint on the backend and have a single deployment (+ a database)
• would love to the backend to be able to specify the auth mechanism / define user model. FastAPI exposes security scheme information in the openapi docs (https://spec.openapis.org/oas/latest.html#security-scheme-object). So it'd be nice to drive the UI using this information.

Let me know if you have any thoughts, if you end up setting up auth in a fork, please let us know -- i'll take a look at the code would be interesting to see :)

[sudhanshu746]

@eyurtsev
sure, I'm happy to contribute. will make changes in a fork and attach PR.