If you’re in the hacking mode - what do you think of taking the Django orm and grafting it onto fast api - sort of like a stand-alone sqlalchemy but with all the ease and power or django’s querysets...
Django ORM is not async so using it with FastAPI would block the event loop. I guess you could wrap the calls in sync_to_async from asgiref but it wouldn't be pretty.
Another option is using something like Tom Christie's orm project (https://github.com/encode/orm), which is a wrapper on top of sqlachemy with a django like interface.
middleware is a part of it, then there's the ORM, caching and anything else that does IO.