py-ty

name	py-ty
description	Run ty (Astral's Python type checker) on Python code. Use when writing, editing, or reviewing Python code to catch type errors. Triggers on: writing Python files, "type check", "run ty", "check types", or after editing .py files.
allowed-tools	["Bash","Read","Edit","Write","Glob","Grep"]

ty — Python Type Checker (Astral)

Fast Python type checker written in Rust. 10-100x faster than mypy/Pyright. Repo: https://github.com/astral-sh/ty

When to use

Run ty check after writing or editing Python code. Always type-check before considering a Python task complete.

Installation

uv tool install ty@latest        # preferred
# or: pip install ty
# or: curl -LsSf https://astral.sh/ty/install.sh | sh

Key commands

ty check                          # check current directory
ty check src/                     # check specific path
ty check --python-version 3.11    # target Python version
ty check --watch                  # incremental watch mode
ty check --output-format concise  # shorter output
ty check --error-on-warning       # strict mode

Configuration

In pyproject.toml:

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