I'm trying to understand the problem: The Directive.options is sub-class specific, so ideally each sub-class would type it as a TypedDict. And in the PR you linked, you would ideally also return a TypedDict from _options_with_language_defaults and use that as argument to _common_option_args.

Is that correct? Where and how would you defined the accepted fields? Like this?

class FooDirective(Directive[MyTypedDict]):
    ...

Would this work at the moment?

class FooDirective(Directive):
    options: MyTypedDict

Diff from mypy_primer, showing the effect of this PR on open source code:

sphinx (https://github.com/sphinx-doc/sphinx)
+ sphinx/domains/python/_object.py:440: error: Unused "type: ignore" comment  [unused-ignore]

Thank you for the review @srittau . I'm experimenting and iterating before answering!