Comment by dcreager

Well ours is not yet implemented, so it's too early to say whether they're compatible. :-)

But less snarkily, we do talk to them often (and the authors of other tools like mypy and pyright) to make sure we aren't introducing gross incompatibilities between the different type checkers. When there are inconsistencies, we want to make sure they are mindful rather than accidental; for good reasons; spec-compliant; and well documented.