Limits on files in the assistants API *at the message level*

I know there’s a limit of 20 files you can attach to the assistant object. However, what I’d like to know is if the files I add in the messages count towards this limit or not.

I’d like to let users of my app upload documents and ask questions about them within that specific conversation thread. Is that something that can be done at a large scale using a single assistant? Eg: there’s 50 concurrent conversations going on with different files attached to them.