Zuban

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
• Releases

Installation / Usage

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.

Local Installation

You can install zuban locally by running:

pip install maturin
git clone --recursive https://github.com/zubanls/zuban
bash scripts/install-locally.sh

Note that your build will not properly work if submodules are not cloned.

Multithreading

Zuban runs multi-threaded by default. To limit the number of threads run it with:

RAYON_NUM_THREADS=1 zuban check

License

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.