Zuban is a high-performance Python Language Server and type checker implemented in Rust, by the author of Jedi. Zuban is 20–200× faster than Mypy, while using roughly half the memory and CPU compared to Ty and Pyrefly. It offers both a PyRight-like mode and a Mypy-compatible mode, which behaves just like Mypy; supporting the same config files, command-line flags, and error messages.

Most important LSP features are supported. Features include diagnostics, completions, goto, references, rename, hover and document highlights.

Zuban passes over 95% of Mypy’s relevant test suite and offers comprehensive support for Python's type system.

Documentation Website

pip install zuban  # Installation

zuban check   # PyRight-like checking
zuban mypy    # Mypy compatibility mode
zmypy         # An alias for zuban mypy
zuban server  # An LSP server

If you want Zuban to pick up your dependencies, please activate the virtual env first.

You can also install the Zuban rust binary using Nix flakes by adding it as an input to your flake.nix:

{
  inputs.zuban.url = "github:zubanls/zuban";

  outputs = { nixpkgs, zuban, ... }: {
    home.packages = [ zuban.packages.${system}.default ];
  };
}

Or install directly via nix profile:

nix profile install github:zubanls/zuban

This project is dual licensed:

• Open Source License: GNU Affero General Public License v3.0 (AGPL-3.0). You may use, modify, and distribute this project under the terms of the AGPL-3.0.
• Commercial License: Available for organizations that prefer not to comply with the AGPL. Contact info (at) zubanls.com for commercial licensing options.