[Question]: Extend to multiple workspaces

[hffmnn]

Hi.

Thank you for this nice example. It's the first time I am looking into GraphQL and AppSync stuff, coming more from the API GW direction. I have one question on how to possibly extend this example:

At which point (in the code) would it be possible to extend the example, to e.g. have multiple workspaces (in Slack lingo). So one user can have multiple workspaces with multiple chat rooms, but not every user can access all the workspaces. Or in SaaS lingo: The service has multiple different tenants.

In API GW I guess I would something like a custom authorizer lambda that can decide based on the users token, if she has access or if not (e.g. like it is done here).

To be clear: I am not asking for a solution here. Maybe some hints in which direction to look. Or maybe some other existing open-source code (doesn't need to be the same language or e.g. CDK, just some well-documented overview on how to do something like that).