A Mypy-compatible Python Language Server built in Rust
Standards-compliant
Fully Featured
Unparalleled Performance
Performance
Extremely fast. Generally 20-200x faster than Mypy - and optimized for lower memory usage.
Features
All relevant LSP features are implemented, completions, goto, references, diagnostics and rename included.
Creation
Developed by the creator of Jedi, ZubanLS applies 14 years of experience in Python auto-completion and static analysis.
Works in VSCode,
Vim,
and all other LSP-compatible editors
This includes Helix, NeoVIM, SublimeText, Emacs, Zed and many others
All Features
Development Tooling
- Mypy config compatibility
- LSP Support: Completions, Goto, Hover, Rename, References, Auto-Import
- Error recovery
- Incremental checking
- Watches files
- Python 3.13 support
- Django support
General Code Understanding
- Passes >95% of Mypy's relevant tests
- Relative, absolute, and stub-only (`.pyi`) imports
- Type narrowing isinstance, assert, etc
- Inferring the type context
- Mypy's --new-type-inference
- Understanding list.append, etc
- Inferring return types
Performance
- Written in Rust
- More than 20-200x faster than Mypy
- Optimized to minimize memory usage
Type System Support
- TypeVar / TypeVarTuple / ParamSpec
- Overloads / NewType / Overrides
- Dataclasses / dataclass_transform
- TypedDict / NamedTuple / Enum
- NewType
- Protocols / Union Types
- Literal Types
- Final / ClassVar / Annotated
- Self Types
- Generic Defaults
- TypeGuard / TypeIs
- ... and much more
Executables
- zubanls - A language server
- zmypy - A drop in replacement for Mypy
- Works on Linux, Mac and Windows
A more comprehensive list can be found in the Documentation. General plugin support is not planned; however, targeted plugins for popular libraries, such as Django, are provided.
Open Source
Zuban is available under an AGPL v3 license. Happy coding!
Commercial licenses are available for organizations that prefer not to comply with the AGPL. Contact us for commercial licensing options.
The ZubanLS Company
In 2012, I created Jedi—a Python auto-completion library that eventually reached millions of users and billions of downloads. But as the ecosystem evolved, one limitation became clear: speed. Jedi’s architecture couldn’t deliver the performance needed for large-scale projects.
In 2020, I started over—with everything I’d learned—building ZubanLS from the ground up in Rust. After five years of full-time work, ZubanLS is now the first truly fast Python language server.
ZubanLS is built for professionals who need precision, reliability and speed. It addresses long-standing issues in tools like Mypy and Pyright by focusing on performance without compromising features. Support for Django, go-to-definition, completions, and all other important LSP features have been implemented. The goal: a tool for perfectionists with deadlines.
If something essential is missing for your use case, feel free to reach out—we’re open to implementing features based on real-world demand.
