ty

# ty

[![ty](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ty/main/assets/badge/v0.json)](https://github.com/astral-sh/ty)
[![PyPI](https://img.shields.io/pypi/v/ty.svg)](https://pypi.python.org/pypi/ty)
[![Discord](https://img.shields.io/badge/Discord-%235865F2.svg?logo=discord&logoColor=white)](https://discord.com/invite/astral-sh)

An extremely fast Python type checker and language server, written in Rust.

<br />

<p align="center">
  <img alt="Shows a bar chart with benchmark results." width="500px" src="https://raw.githubusercontent.com/astral-sh/ty/main/docs/assets/ty-benchmark-cli.svg">
</p>

<p align="center">
  <i>Type checking the <a href="https://github.com/home-assistant/core">home-assistant</a> project without caching.</i>
</p>

<br />

ty is backed by [Astral](https://astral.sh), the creators of
[uv](https://github.com/astral-sh/uv) and [Ruff](https://github.com/astral-sh/ruff).

ty is currently in [beta](#version-policy).

## Highlights

- 10x - 100x faster than mypy and Pyright
- Comprehensive [diagnostics](https://docs.astral.sh/ty/features/diagnostics/) with rich contextual information
- Configurable [rule levels](https://docs.astral.sh/ty/rules/), [per-file overrides](https://docs.astral.sh/ty/reference/configuration/#overrides), [suppression comments](https://docs.astral.sh/ty/suppression/), and first-class project support
- Designed for adoption, with support for [redeclarations](https://docs.astral.sh/ty/features/type-system/#redeclarations) and [partially typed code](https://docs.astral.sh/ty/features/type-system/#gradual-guarantee)
- [Language server](https://docs.astral.sh/ty/features/language-server/) with code navigation, completions, code actions, auto-import, inlay hints, on-hover help, etc.
- Fine-grained [incremental analysis](https://docs.astral.sh/ty/features/language-server/#fine-grained-incrementality) designed for fast updates when editing files in an IDE
- Editor integrations for [VS Code](https://docs.astral.sh/ty/editors/#vs-code), [PyCharm](https://docs.astral.sh/ty/editors/#pycharm), [Neovim](https://docs.astral.sh/ty/editors/#neovim) and more
- Advanced typing features like first-class [intersection types](https://docs.astral.sh/ty/features/type-system/#intersection-types), advanced [type narrowing](https://docs.astral.sh/ty/features/type-system/#top-and-bottom-materializations), and
    [sophisticated reachability analysis](https://docs.astral.sh/ty/features/type-system/#reachability-based-on-types)

## Getting started

Run ty with [uvx](https://docs.astral.sh/uv/guides/tools/#running-tools) to get started quickly:

```shell
uvx ty check
```

Or, check out the [ty playground](https://play.ty.dev) to try it out in your browser.

To learn more about using ty, see the [documentation](https://docs.astral.sh/ty/).

## Installation

To install ty, see the [installation](https://docs.astral.sh/ty/installation/) documentation.

To add the ty language server to your editor, see