ty

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

ty is backed by Astral, the creators of uv and Ruff.

Highlights:

• 10x - 100x faster than mypy and Pyright
• Comprehensive diagnostics with rich contextual information
• Configurable rule levels, per-file overrides, suppression comments, and first-class project support
• Designed for adoption, with support for redeclarations and partially typed code
• Language server with code navigation, completions, code actions, auto-import, inlay hints, on-hover help, etc.
• Fine-grained incremental analysis designed for fast updates when editing files in an IDE
• Editor integrations for VS Code, PyCharm, Neovim and more
• Advanced typing features like first-class intersection types, advanced type narrowing, and sophisticated reachability analysis