Pyright is a fast type checker meant for large Python source bases. It can run in a "watch" mode and performs fast incremental updates when files are modified.
Pyright supports [configuration files](/docs/configuration.md) that provide granular control over settings. Different "execution environments" can be associated with subdirectories within a source base. Each environment can specify different module search paths, python language versions, and platform targets.
Pyright includes a recent copy of the stdlib type stubs from [Typeshed](https://github.com/python/typeshed). It can be configured to use another (perhaps more recent or modified) copy of the Typeshed type stubs. Of course, it also works with custom type stub files that are part of your project.
Pyright includes both a [command-line tool](/docs/command-line.md) and an [extension for Visual Studio Code](https://marketplace.visualstudio.com/items?itemName=ms-pyright.pyright) that implements the [Language Server Protocol](https://microsoft.github.io/language-server-protocol/).
For rich Python editing and debugging capabilities with Visual Studio Code, be sure to also install the official [Microsoft Python extension for Visual Studio Code](https://marketplace.visualstudio.com/itemdetails?itemName=ms-python.python) as Pyright only provides syntax and type checking.
You can install the latest-published version of the Pyright VS Code extension directly from VS Code. Simply open the extensions panel and search for `pyright`.
The latest version of the command-line tool can be installed with npm, which is part of node. If you don't have a recent version of node on your system, install that first from [nodejs.org](nodejs.org).
Pyright provides some features that overlap with functionality provided by the standard VS Code Python extension: "hover", type completion, definitions, references, rename symbols, etc. You may see duplicate results if Pyright is installed alongside the Python extension. There is currently no way to disable this functionality in the Python extension. If you want to disable these features in Pyright, there is a setting to do so: `pyright.disableLanguageServices`.
Do you have questions about Pyright or Python type annotations in general? Post your questions in this [gitter channel](https://gitter.im/microsoft-pyright/community).
**A:** Pyright is focused on type checking. The Python VS Code plugin is Microsoft's officially-supported extension for VS Code and provides a diverse array of features including debugging, test case management, linter plugins, and more. Pyright can be used alongside the Microsoft Python extension.
**A:** Pyright is a side project with no dedicated team. There is no guarantee of continued development on the project. If you find it useful, feel free to use it and contribute to the code base.
This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.
When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.
This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/). For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.
