@zachdaniel The resource can be an existing table managed by another schema as well right? I don’t see Ash restricting that. In this case, Organization can be both a plain Ecto Schema as well as an Ash Resource?

I use mix phx.gen.auth for generating my auth schemas and liveview endpoints. I haven’t switched to use Ash Authentication yet. However, I still need to refer to the User records in my Ash Resources. So I created a resource file for the existing User schema with only email field (I don’t want the password fields exposed on my Ash Resoruce) and it works fine. Not sure, if this has any drawbacks. It would be good to know from you.

Correct, no issues there.

Add

postgres do
  migrate? false
end

To skip Generating migrations for it

Good heavens, I should spend more time reading the Ash docs. It is truly pragmatic.