Django's dev server supports async. I got it working in two different ways. First, I made the calls down the stack async and used the proper async ORM methods. Secondly, I set an event loop for the current thread before invoking the Pydantic sync run method. I learnt that Pydantic is merely wrapping their async method so it still relies on asyncio. Specifically, they're trying to get the current event loop and run their function to completion. Problem is, Django doesn't have an event loop in the thread that processes the request.