I would welcome a generic as described by the OP. However, I would discourage allowing "any user defined object" since the click docs clearly indicate that ctx.obj is a dict type. As such, I wouldn't want the ability for ctx.obj to be, for example, a list.

Alternatively, the typing could allow any subclass of click.Context. That way code like the following could be used to define custom context schemas.

import click
from typing import TypedDict

class MyContextObj(TypedDict):
  foo: int
  bar: str

class MyContext(click.Context)
  obj: MyContextObj

@click.command()
@click.pass_context
def my_command(ctx: MyContext):
  ctx.obj # Type checkers can tell that this has keys `foo: int` and `bar: str`

Unfortunately, this code currently throws the following typing error when checked by mypy:

Argument 1 to "pass_context" has incompatible type "Callable[[MyContext, Iterable[str]], Any]"; expected "Callable[[Context, Iterable[str]], Any]"

Pleasantly surprised to see some people are also looking for this. I'll look into this this week and will come with a PR that will hopefully be accepted.

Unfortunately, this code currently throws the following typing error when checked by mypy:

This can be fixed by using a TypeVar in the pass_context signature, however I don't think this is a great idea, as this isn't type safe: at runtime, ctx is still an instance of Context.

the click docs clearly indicate that ctx.obj is a dict type.

I couldn't find anything stating this. Do you know in which section of the docs this is described? The type hint for obj is Any, so I think you can allow any object.

the click docs clearly indicate that ctx.obj is a dict type.

I couldn't find anything stating this. Do you know in which section of the docs this is described? The type hint for obj is Any, so I think you can allow any object.

You appear to be correct. I was looking at the code example for Nested Handling and Contexts which includes an assertion that ctx.obj is a dict. That said, upon closer look it appears that one could assert that ctx.obj is indeed any type.