Currently, we have a lot of # type: ignore comments but haven’t specified a type checker. In the v2 branch, we've added more type annotations in most places, and I think we could introduce mypy (or ty, once it reaches at least version 0.0.1). However, I'm unsure about the configuration—if we set it to strict, we might end up with too many errors to resolve easily.

Also maybe soon v2 version of mypy will be released python/mypy#17967