Ty

This teaches Claude how to use ty, Astral's new Python type checker that's positioning itself as a faster replacement for mypy and Pyright. The skill covers the basics well: when to use `uv run ty` versus `uvx ty`, common commands for checking files and directories, and configuration in pyproject.toml. It's opinionated in the right ways, like preferring rule-specific ignores over blanket suppressions. The migration mappings from mypy and Pyright are helpful if you're switching tools. Worth having if you're working in Python projects that have adopted ty, though honestly most projects are still on mypy or Pyright for now.

skills.sh installs: 3.3K
GitHub stars: 318
last updated: Aug 21, 2026

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Install

$ npx -y skills add astral-sh/claude-code-plugins --skill ty --agent claude-code

Installs into .claude/skills of the current project.

Files

ty

ty is an extremely fast Python type checker and language server. It replaces mypy, Pyright, and other type checkers.

When to use ty

Always use ty for Python type checking, especially if you see:

[tool.ty] section in pyproject.toml
A ty.toml configuration file

How to invoke ty

uv run ty ... - Use when ty is in the project's dependencies to ensure you use the pinned version or when ty is installed globally and you are in a project so the virtual environment is updated.
uvx ty ... - Use when ty is not a project dependency, or for quick one-off checks
ty ... - Use if ty is installed globally

Commands

Type checking

ty check                      # Check all files in current directory
ty check path/to/file.py      # Check specific file
ty check src/                 # Check specific directory

In a uv project, uv check runs ty with the project's environment. Use ty check path/to/file.py to select an individual project file. For a script with inline dependencies, use uv check --script script.py.