Typecheckers cannot see beyond the *args: Any, **kwargs: Any arguments, they will allow literally anything as long as the first 2 arguments are satisfied.

In order to fix this, it would be necessary to add complete signatures, duplicating the arguments from DRF itself.

I see.

What I would like is to inform what this mixing "soft-inherits" from, but without really creating an inheritance. Duplicating code from DRF is not something that I want. In fact, DRF made some small internal adjustment so drf-nested-routers got able to override just a little part of the routers, instead of copy-pasting some lines.

That makes me think that DRF may be open to small changes that facilitate what you want, if this does not reduce their code readability.

I will close this here because looks like it got fixed on typeddjango/djangorestframework-stubs#610 already.

Please reopen if I am mistaken.

The changes in djangorestframework-stubs don't really solve the issue I described in this PR. But I also understand not wanting to duplicate the signatures here downstream, fair enough.