ty

ty is an extremely fast Python type checker and language server written in Rust, developed by Astral (the team behind Ruff). It is designed to bring high-performance static type analysis to Python projects, catching type errors before runtime. ty integrates as a language server to provide real-time diagnostics, hover information, and code intelligence directly in your editor.

• Blazing-fast type checking — Written in Rust for maximum performance, ty analyzes Python codebases significantly faster than traditional type checkers.
• Language server protocol (LSP) support — Provides real-time type diagnostics, hover types, and go-to-definition in any LSP-compatible editor.
• Python type inference — Infers types across your codebase without requiring explicit annotations everywhere.
• CLI interface — Run ty check from the command line to get type errors across your project instantly.
• Early-stage / pre-release — ty is currently in active development and pre-release; install via pip install ty or from the GitHub releases page.
• Astral ecosystem — Built by the same team behind Ruff, designed to complement fast Python tooling workflows.