Inherit __init_subclass__ args to subclass

I'm using msgspec for API response validation, so I wrote this:

class Response(Struct, frozen=True, kw_only=True):
    pass

So all of the responses should be created by passing kwargs, and they can't be modified by accident.

But when I use this:

class SomeResponse(Response):
    field: int

test = SomeResponse(1)  # successed, oops...

Seems that args for __init_subclass__ can't be inherited.

So how can I do to implement this? Should I use metaclass or something else?

Currently I'm using this:

RESPONSE_CONFIG = {
    "kw_only": True,
    "frozen": True
}

class SomeResponse(Struct, **RESPONSE_CONFIG):
    field: int

It works, but ugly and I can easily forget to add CONFIG, which result in non-restricted response struct.

Start by reproducing the Response and SomeResponse examples and inspect Struct's init_subclass handling. Determine the intended inheritance semantics for kw_only and frozen, then add focused tests showing that subclass construction remains keyword-only and immutable when those options are set on the parent.