Use One Supabase Instance as the Authentication Provider for Other Supabase Instances?

I was wondering if anyone has ever attempted or successfully been able to use one supabase instance as an authentication provider (in the same way as Keycloak, Google, Facebook, etc) for other supabase instances? Here's the use case: • we have some clients who use a shared/multi-tenant database environment • we have some clients who require a single-tenant database environment • we have some clients who will be using both (i.e., one of their corporate accounts pays the premium for single tenancy and the other does not) • we want to have a centralized, unified login experience (i.e., a single page that shows all of a user's accounts, one per company/tenant) Current Solution • we're running a Keycloak instance to use as a central authentication provider • the issue is that this requires us to federate the supabase instances, such that the central keycloak server needs its own supabase database to pool/collect data from all…