https://github.com/alcarney/vscode-wasi-pygls

An experiment for running pygls powered language servers in VSCcode's WASI host
https://github.com/alcarney/vscode-wasi-pygls

language-server pygls python vscode-extension wasi webassembly

Last synced: 10 months ago
JSON representation

An experiment for running pygls powered language servers in VSCcode's WASI host

• Host: GitHub
• URL: https://github.com/alcarney/vscode-wasi-pygls
• Owner: alcarney
• License: mit
• Created: 2024-01-05T21:00:31.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2025-07-15T18:35:03.000Z (11 months ago)
• Last Synced: 2025-07-16T16:21:51.666Z (11 months ago)
• Topics: language-server, pygls, python, vscode-extension, wasi, webassembly
• Language: TypeScript
• Homepage:
• Size: 1.13 MB
• Stars: 4
• Watchers: 3
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

Awesome Lists containing this project

README

          
# vscode-wasi-pygls [![Visual Studio Marketplace Version](https://img.shields.io/visual-studio-marketplace/v/swyddfa.pygls-wasi-playground?style=flat-square)](https://marketplace.visualstudio.com/items?itemName=swyddfa.pygls-wasi-playground)



  



## Usage

It is possible to use this extension in a local version of VSCode however, its primary purpose is to demonstrate that it is possible to run a language server written with [pygls](https://pygls.readthedocs.io/en/latest/index.html) entirely in the browser!

- Open https://vscode.dev/github/openlawlibrary/pygls, you will need to sign into GitHub before the repository's content will load.

- Install the `swyddfa.pygls-wasi-playground` extension

- By default, the extension will be configured to launch the `examples/servers/code_action.py` server, though this can be changed by setting the `pygls.server.launchScript` option.

- Open the `examples/servers/workspace/sums.txt` file

- Wait for the server to boot up (will take 2-3min to load all the required resources over the network)

This extension is a WASI port of the pygls-playground extension from the upstream project, see the [documentation](https://pygls.readthedocs.io/en/latest/servers/howto/use-the-pygls-playground.html) for more details on its usage.

Note that some features (like debugging!) have not yet been implemented.

## Acknowledgements

This stands on the shoulders of a lot of excellent projects and resources, without which this would be impossible.

**Projects**

- [openlawlibrary/pygls](https://github.com/openlawlibrary/pygls): For making it possible to write language servers in Python

- [brettcannon/cpython-wasi-build](https://github.com/brettcannon/cpython-wasi-build): For providing the WASI build of CPython

- [microsoft/vscode-wasm](https://github.com/microsoft/vscode-wasm): For implementing the WASI host in VSCode as well as the following code snippets, showing how to connect everything up

  - [vscode-wasm/testbeds/python/extension.ts](https://github.com/microsoft/vscode-wasm/blob/65669200000306d174ce2bbfdd9e4d41e9517466/testbeds/python/extension.ts#L17-L38)

  - [vscode-wasm/testbeds/lsp-rust/client/src/extension.ts](https://github.com/microsoft/vscode-wasm/blob/65669200000306d174ce2bbfdd9e4d41e9517466/testbeds/lsp-rust/client/src/extension.ts#L18-L48)

  - [vscode-wasm/testbeds/lsp-rust/client/src/lspServer.ts](https://github.com/microsoft/vscode-wasm/blob/65669200000306d174ce2bbfdd9e4d41e9517466/testbeds/lsp-rust/client/src/lspServer.ts)

**Resources**

- [Testing a Python project using the WASI build of CPython with pytest](https://snarky.ca/testing-a-project-using-the-wasi-build-of-cpython-with-pytest/): For showing how to build and use a Python environment with the WASI build of CPython

- [VSCode and WebAssemblies](https://code.visualstudio.com/blogs/2023/06/05/vscode-wasm-wasi)