Jupyter AI inline completion context

What context does Jupyter AI inline text completion have? I can’t find it in any of the docs.
Does it have:

I have reason to believe it has context from other notebooks in the directory… but unclear.

I do see Developers — Jupyter AI documentation
Mentioning explicitly retrieving saved notebook state. I do have some pretty strong evidence that my custom provider is accessing other saved notebooks in the directory

By default it has very little context, only the current cell. But custom providers can do anything idneed.