Released on 2026-03-02.

- Disallow negative narrowing for `isinstance()` or `issubclass()` checks involving `type[]` types ([#23598](https://github.com/astral-sh/ruff/pull/23598))

- Fix binary operations between an instance of a `NewType` of `float` and an instance of `Any`/`Unknown` ([#23620](https://github.com/astral-sh/ruff/pull/23620))

- Fix bug where ty would think that a `Callable` with a variadic positional parameter could be a subtype of a `Callable` with a positional-or-keyword parameter ([#23610](https://github.com/astral-sh/ruff/pull/23610))

- Fix inference of `t.__mro__` if `t` is an instance of `type[Any]` ([#23632](https://github.com/astral-sh/ruff/pull/23632))

- Fix overloaded callable assignability for unary `Callable` targets ([#23277](https://github.com/astral-sh/ruff/pull/23277))

- Limit recursion depth when displaying self-referential function types ([#23647](https://github.com/astral-sh/ruff/pull/23647))

- Ensure that `python -m ty` works even when ty was installed into an ephemeral virtual environment ([#2852](https://github.com/astral-sh/ty/pull/2852))

- Add support for the LSP protocol's "type hierarchy" feature ([#23566](https://github.com/astral-sh/ruff/pull/23566))

- Add more ParamSpec validation for `P.args` and `P.kwargs` ([#23640](https://github.com/astral-sh/ruff/pull/23640))

- Ban nested `Required`/`NotRequired`, and ban them both outside of `TypedDict` fields ([#23627](https://github.com/astral-sh/ruff/pull/23627))

- Detect inconsistent generic base class specializations that appear in the same MRO ([#23615](https://github.com/astral-sh/ruff/pull/23615))

- Detect invalid uses of `@final` on non-methods ([#23604](https://github.com/astral-sh/ruff/pull/23604))

- Add partial support and validation for `Unpack` when used with tuple types ([#23651](https://github.com/astral-sh/ruff/pull/23651))

- Recurse into tuples and nested tuples when applying special-cased validation of arguments passed to `isinstance()` and `issubclass()` ([#23607](https://github.com/astral-sh/ruff/pull/23607))

- Reject ellipsis literals in odd places in type/annotation expressions ([#23611](https://github.com/astral-sh/ruff/pull/23611))

- Reject functions with PEP-695 type parameters that shadow type parameters from enclosing scopes ([#23619](https://github.com/astral-sh/ruff/pull/23619))

- Reject generic metaclasses parameterized by type variables ([#23628](https://github.com/astral-sh/ruff/pull/23628))

- Treat `dataclass_transform` dataclasses as neither frozen nor non-frozen ([#23366](https://github.com/astral-sh/ruff/pull/23366))

- Validate that type variable defaults don't reference later type parameters or type parameters out of scope ([#23623](https://github.com/astral-sh/ruff/pull/23623))

- Sync vendored typeshed stubs ([#23642](https://github.com/astral-sh/ruff/pull/23642)). [Typeshed diff](https://github.com/python/typeshed/compare/1b3cec156330a93f6bb22b6636bca38c27f8f721...843c1fd5a148da85e523c1b4ee680226f89986aa)

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