Not really because Phoenix handles the web layer while Ash handles the domain/application layer. In other words Phoenix provides one interface, of potentially many, through which users could access an application built in Ash.

Which is all to say if there's been something I couldn't figure out in Ash I've tended to put it into a regular Elixir module rather than anything Phoenix-specific.

The only exception I can think of is that AshAuthentication doesn't provide support for API keys out of the box, so I have ended up writing my own little plugs for that.

If you are just getting started I'd strongly recommend working through tutorials and/or the Ash book (it's in beta but pretty solid) rather than just diving into a project. It's a lot when you're first wrapping your head around it.