# Astral ty Usage Reference

Use this page when you want to run or adopt [ty](https://docs.astral.sh/ty/), Astral's Python type checker and language server, in a typing-focused workflow.

## Quick Start

- Run a one-off check without installing globally: `uvx ty check`
- Run checks in the current project: `ty check`
- Explore behavior quickly in the [ty playground](https://play.ty.dev/)

Primary docs:

- [Getting started](https://docs.astral.sh/ty/#getting-started)
- [Installation](https://docs.astral.sh/ty/installation/)
- [Type checking](https://docs.astral.sh/ty/type-checking/)
- [CLI reference](https://docs.astral.sh/ty/reference/cli/)

## Editor Integration

Use ty as a language server in supported editors.

- [Editor integration overview](https://docs.astral.sh/ty/editors/)
- [VS Code setup](https://docs.astral.sh/ty/editors/#vs-code)
- [Language server capabilities](https://docs.astral.sh/ty/features/language-server/)
- [Editor settings reference](https://docs.astral.sh/ty/reference/editor-settings/)

## Configuration Surface

Start from project defaults, then add targeted overrides only where needed.

- [Configuration guide](https://docs.astral.sh/ty/configuration/)
- [Configuration reference](https://docs.astral.sh/ty/reference/configuration/)
- [Python version handling](https://docs.astral.sh/ty/python-version/)
- [Module discovery](https://docs.astral.sh/ty/modules/)
- [File exclusions](https://docs.astral.sh/ty/exclusions/)

## Rule And Suppression Controls

Use this set when tuning signal-to-noise in large or partially typed codebases.

- [Rules overview](https://docs.astral.sh/ty/rules/)
- [Rules reference](https://docs.astral.sh/ty/reference/rules/)
- [Suppression comments and directives](https://docs.astral.sh/ty/suppression/)
- [Diagnostics feature docs](https://docs.astral.sh/ty/features/diagnostics/)

## Migration Notes

For teams moving from existing type checkers, use Astral's migration guidance first.

- [Coming from mypy or pyright](https://docs.astral.sh/ty/coming-from-mypy-or-pyright/)
- [Typing FAQ](https://docs.astral.sh/ty/reference/typing-faq)

## Suggested Review Flow With ty

1. Confirm Python baseline and project targets.
2. Run `uvx ty check` for an initial signal pass.
3. Configure version/module/discovery settings as needed.
4. Triage diagnostics and tune rules or suppressions deliberately.
5. Re-run checks and keep modernization changes behavior-preserving unless explicitly requested.