There are quite a few authentication services and libraries out there, but the vast majority treats tenants / organizations as an afterthought - in case of Firebase, tenants are literally in a different product.

In B2B apps, users, tenants and data as fundamentally interrelated - users belong to tenants and authenticate in order to access data that belongs to the tenant. This means that user and auth data belong in the same database where the tenant data is stored (in our case, Postgres), and that the database should be aware of the user identity and control the access to tenant data.

You can read more about our thoughts on authentication and data in our blog: https://www.thenile.dev/blog/introducing-nile-auth

We'd love your feedback - both on the approach and the project itself.