# Early Explorations of Astral's Red Knot Type Checker

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Update (May 5, 2025): Red Knot has been renamed [ty](https://pydevtools.com/handbook/reference/ty.md).
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A recent [blog post by Michael Jurasovic](https://jurasofish.github.io/a-very-early-play-with-astrals-red-knot-static-type-checker.html) explores Astral's upcoming static type checker, Red Knot. The tool is under active development with an [alpha release targeted for PyCon 2025](https://github.com/astral-sh/ruff/milestone/22).

## Findings

* Build Process: The author used Claude to analyze the Ruff codebase and successfully compiled Red Knot from source using Cargo
* Configuration: Red Knot uses a `[tool.knot]` section in `pyproject.toml` for configuration
* Performance: Initial benchmarks showed Red Knot running approximately 100x faster than mypy on cold starts
* Stability: As expected for pre-release software, there were some crashes on larger codebases (SQLAlchemy, mypy) and numerous errors on others

Red Knot runs approximately 100x faster than [mypy](https://pydevtools.com/handbook/reference/mypy.md) on cold starts. The tool still crashes on some larger codebases and produces errors on others, but the speed gains suggest Red Knot could change how Python developers approach type checking.