zuban

What it is and what it does

Zuban is a Python language server and type checker written in Rust, designed as a faster alternative to Mypy and other type checkers. It runs in two primary modes: a PyRight-like mode for modern type checking and a Mypy-compatible mode that accepts the same configuration files, command-line flags, and error messages as Mypy. This makes it a drop-in replacement for teams already using Mypy who want better performance without rewriting their type-checking setup.

The package provides full LSP support, enabling IDE integration for real-time diagnostics, code completion, go-to-definition, find references, rename refactoring, hover information, and document highlights. It has no runtime dependencies, only requires Python 3.7 or later, and is distributed as pre-compiled wheels for macOS (Intel and ARM), Linux (multiple architectures including ARM), Windows, and musl-based systems. The project is actively maintained and carries an AGPL-3.0 license with commercial licensing available.

Use it for:

• Replace Mypy in an existing project to speed up type checking in CI/CD pipelines while keeping the same config and error format.
• Integrate a fast type checker into an IDE or editor via LSP for real-time type diagnostics and code completion.
• Perform static type analysis on large Python codebases where Mypy's speed becomes a bottleneck.
• Set up a development environment with PyRight-like checking without switching away from Mypy's familiar interface.
• Use as a command-line type checker (zmypy alias) in scripts and automation where performance matters.

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Zuban is a Rust-based Python language server and type checker offering Mypy-compatible and PyRight-like checking modes, with LSP support for diagnostics, completions, goto, references, rename, hover, and document highlights.

Yes, if you need a faster type checker and can accept the AGPL-3.0 license (or purchase a commercial license). Zuban is actively maintained, has no runtime dependencies, and offers both Mypy and PyRight compatibility modes. The medium install friction is offset by pre-built wheels across many platforms. Verify performance claims and type system coverage against your specific codebase before committing to production use.

Install

zuban on PyPI

pip install zuban

uv add zuban

poetry add zuban

Installing zuban

Before you install

Medium install friction due to compiled wheels across multiple platforms (macOS, Linux, Windows, ARM variants). Active maintenance with recent releases; last commit 2026-08-12 and version 0.9.1 released 2026-07-31. No runtime dependencies simplifies deployment.

License in practice

Dual-licensed under AGPL-3.0 for open-source use and a proprietary commercial license. AGPL-3.0 requires you to share modifications and derivative works under the same license; commercial licensing available from zubanls.com for organizations preferring different terms.

Quickstart

pip install zuban

zuban check          # PyRight-like type checking
zuban mypy           # Mypy-compatible mode
zuban server         # Start LSP server

Requires Python 3.7 or later; virtual environment activation recommended so Zuban can detect project dependencies.

Verify before relying

• Actual performance comparison data (20–200× faster than Mypy) and memory/CPU usage claims need independent verification.
• Claim that Zuban passes over 95% of Mypy's test suite—specific test suite scope and version alignment unclear.
• Extent of comprehensive type system support and which Python typing features are fully implemented.

Package facts

Evidence: zuban-0.9.1-py3-none-macosx_10_12_x86_64.whl; zuban-0.9.1-py3-none-macosx_11_0_arm64.whl; zuban-0.9.1-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl; zuban-0.9.1-py3-none-manylinux_2_17_armv7l.manylinux2014_armv7l.whl; zuban-0.9.1-py3-none-manylinux_2_17_i686.manylinux2014_i686.whl; zuban-0.9.1-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl; zuban-0.9.1-py3-none-musllinux_1_2_aarch64.whl; zuban-0.9.1-py3-none-musllinux_1_2_armv7l.whl; zuban-0.9.1-py3-none-musllinux_1_2_i686.whl; zuban-0.9.1-py3-none-musllinux_1_2_x86_64.whl; zuban-0.9.1-py3-none-win32.whl; zuban-0.9.1-py3-none-win_amd64.whl

Keywords: typechecking, mypy, static, analysis, autocompletion

Tags

More Python Modules packages