# Ty — Astral's Fast Python Type Checker

> Ty is Astral's Rust-based Python type checker and language server. Use it to trial fast type feedback next to Ruff and uv before standardizing on CI.

## Install

Copy the content below into your project:

## Quick Use

1. Install the verified package or repo entrypoint:

```bash
uv tool install ty
```

2. Run the first local check:

```bash
ty check .
```

3. Add a repeatable verification command:

```bash
ty check .
```

---

## Intro

Ty is a verified GitHub-backed tool for modern AI and developer workflows, sourced from `astral-sh/ty` with 18,572 stars and a MIT license snapshot. Best for: Python teams that already like Astral tooling and want faster type feedback without rewriting the project around a new framework. Works with: Python projects, pyproject.toml, uv-managed environments, editor language-server workflows. Setup time: 6 minutes. Use it when you need a concrete, repeatable path rather than another one-off shell snippet.

---

## Operating Pattern

### Fit check

| Question | Practical answer |
|---|---|
| What do you install? | `ty` from `astral-sh/ty` |
| What is the first command? | `ty check .` |
| What proves it works? | `ty check .` |
| How long should a pilot take? | 6 minutes for a small repo or sandbox |

### Adoption loop

1. Run the tool on a disposable branch or sandbox project.
2. Capture before/after output so reviewers can see the exact effect.
3. Add the smallest CI or local check that prevents regressions.
4. Document owner, upgrade command, and rollback command in the repo.

### Recommended use

Run Ty beside your current checker for a week. Compare false positives, speed, and editor feedback before deciding whether to make it a required CI gate.

### Guardrails

Mark it as an evaluation tool in docs if your team still relies on mypy or pyright for final enforcement.

### Rollout checklist

- Pin the package or release version before using it in CI.
- Keep credentials in environment variables or the platform secret store.
- Add one owner who is responsible for upgrades and breaking-change triage.
- Re-check the GitHub repo before writing docs that mention APIs or install paths.


---

### FAQ

**Q: Is this production-ready?**
A: The repo exists at `https://github.com/astral-sh/ty` and has 18,572 GitHub stars. Treat the first rollout as a controlled pilot until your team has tested install, rollback, and CI behavior.

**Q: Why use it instead of a generic script?**
A: The value is repeatability: a named package, a documented command, a source repo, and a small verification path that can be reviewed by teammates.

**Q: What should I measure first?**
A: Measure setup time against the 6 minutes target, count how many files or tasks it changes, and record whether the CI command catches the same issue locally.

---

## Source & Thanks

> Built from [astral-sh/ty](https://github.com/astral-sh/ty). License: MIT.
>
> GitHub stars verified from `api.github.com/repos/astral-sh/ty`: 18,572.

---

<!-- ZH -->

## 快速使用

1. 安装已验证的包或仓库入口：

```bash
uv tool install ty
```

2. 跑第一次本地检查：

```bash
ty check .
```

3. 加一个可重复验证命令：

```bash
ty check .
```

---

## 简介

Ty 是一个已通过 GitHub 仓库验证的现代 AI / 开发者工具，来源 `astral-sh/ty`，当前星标快照 18,572，许可证 MIT。适合：已经喜欢 Astral 工具、希望更快获得类型反馈但不想围绕新框架重写项目的 Python 团队。兼容：Python 项目、pyproject.toml、uv 管理的环境、编辑器 language-server 工作流。装机时间：6 minutes。当你需要的是可重复落地路径，而不是一次性 shell 片段时，用它。

---

## 操作模式

### 适配检查

| 问题 | 实用答案 |
|---|---|
| 安装什么？ | 来自 `astral-sh/ty` 的 `ty` |
| 第一条命令？ | `ty check .` |
| 如何证明可用？ | `ty check .` |
| 小范围试点多久？ | 小仓库或 sandbox 约 6 minutes |

### 接入循环

1. 先在一次性分支或 sandbox 项目里跑。
2. 记录 before / after 输出，让 reviewer 看见实际影响。
3. 加最小的 CI 或本地检查，防止同类问题回归。
4. 在仓库文档里写清 owner、升级命令和回滚命令。

### 推荐用法

让 Ty 和现有类型检查器并跑一周。比较误报、速度和编辑器反馈后，再决定是否把它设为 CI 必过项。

### 风险边界

如果团队仍依赖 mypy 或 pyright 做最终约束，就在文档里明确 Ty 处于评估阶段。

### 推广检查表

- 进入 CI 前固定包版本或 release 版本。
- 凭据放进环境变量或平台 secret store。
- 指定一个 owner 负责升级和 breaking change 分流。
- 文档里写 API 或安装路径前，重新核验 GitHub 仓库。


---

### FAQ

**Q: 能直接上生产吗？**
A: 仓库已验证存在：`https://github.com/astral-sh/ty`，GitHub 星标 18,572。第一次上线仍建议控制试点，先验证安装、回滚和 CI 行为。

**Q: 为什么不用普通脚本？**
A: 价值在可重复：有命名包、文档化命令、源仓库和可被团队 review 的最小验证路径。

**Q: 第一步应该量什么？**
A: 先量装机时间是否接近 6 minutes，它改了多少文件或任务，以及 CI 命令是否能在本地抓到同类问题。

---

## 来源与感谢

> 来源：[astral-sh/ty](https://github.com/astral-sh/ty)。许可证：MIT。
>
> GitHub stars 已通过 `api.github.com/repos/astral-sh/ty` 验证：18,572。


---
Source: https://tokrepo.com/en/workflows/ty-astral-s-fast-python-type-checker
Author: Astral