@alan-rutter Makes perfect sense to me, I have a very similar scenario -- building a React SPA with a custom .NET backend. Unfortunately there seems to be very little documentation for building a custom backend.

Have you looked here?
https://github.com/FusionAuth/fusionauth-javascript-sdk-express#server-code-requirements

That's what you and I both need to implement in our .NET backend. Then you should be able to use the Angular SDK to connect to it. It's just a bit irritating that there's not already a reference implementation for this.

I'm working on implementing the OAuth auth code grant flow with a custom backend and a SPA frontend with Jwt access & refresh tokens:
https://fusionauth.io/articles/login-authentication-workflows/spa/oauth-authorization-code-grant-jwts-refresh-tokens-cookies

The above doc diagrams and describes the flow in pretty good detail, but haven't found much practical guidance on actual implementation. Surprising, considering this is a pretty much becoming the industry standard -- and it's even listed as a "Recommended" approach for SPAs.

I did find this, which I'm able to adapt easily enough (especially combined with the SPA Getting Started guides):
https://github.com/FusionAuth/fusionauth-javascript-sdk-express

But I still would have expected to see multiple reference implementations for this scenario, and probably a few Getting Started guides. Can't help but wonder if there is a document or repository I'm missing?

@vandaele-seba @mark-robustelli
I agree that it seems non-intuitive. I'm building a B2B2C multi-tenant application; it's very awkward trying to shoehorn things in the other way around.

In my case, we have user accounts that can exist in, and have different permissions to, different tenant instances of the same application. I'm planning to work around this by using API to creating a new instance of the application from a sort of hard-coded template every time I create a tenant, and creating duplicates of users in the same fashion. But it's certainly awkward, I wish there were a way to share Applications and Users across tenants.

OR, perhaps a new concept is needed in FusionAuth -- "Organizations" if you will -- that allows for granting users with different permission sets inside the same Application.