#astral

A veritable garden of linters and type checkers has blossomed in the Python ecosystem. Pyright and Mypy are two of the most popular, while Astral’s ty and Meta’s Pyrefly are two promising Rust-based newcomers. We compared early-stage ty and Pyrefly last June. One year later, Meta has released Pyrefly 1.0. Pyrefly is intended to stand out from the pack by way of a few key features. It’s written in Rust for performance and memory efficiency, and it has a number of intriguing forward-looking features, some still experimental. Setting up Pyrefly Pyrefly installs into a Python environment like any other Python type checker (pip install pyrefly) and brings with it no additional dependencies. Visual Studio Code users can work with Pyrefly via an extension, but the extension doesn’t give you access to the command-line tools offered by Pyrefly when it’s installed in a project venv. You can start using Pyrefly right away, with no actual setup. If Pyrefly detects no configuration for a given pro