---
id: zuban
version: "0.9.1"
license: AGPL-3.0-only
license_treatment: agpl
maintenance: active
---

# zuban — Zuban - The Zuban Language Server

License: agpl · Maintenance: active · Downloads: 240.4K/mo

## 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 above — 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

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

- License: AGPL-3.0-only (agpl)
- Python support: supports_current
- Install friction: medium
- Maintenance: active
- Downloads: 240.4K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

python type checker, language server protocol, mypy alternative, static type analysis, lsp python, fast type checking, python linter, type-checking, lsp, rust-based

[View on SkillFed](https://skillfed.io/packages/zuban) · [View on PyPI](https://pypi.org/project/zuban/)