Stim for VS Code

Syntax highlighting and interactive circuit visualization for Stim .stim and .dem files.

Diagrams are produced by Stim's C++ core compiled to WebAssembly, so the output matches Stim exactly and runs entirely inside the editor with no Python or native dependencies.

Features

• Syntax highlighting for .stim and .dem files.
• Autocomplete for gate and annotation names.
• Circuit visualizer opened from the editor title bar or the Stim: Visualize Circuit command.
• Diagram types: timeline-svg, timeline-3d, timeslice-svg, detslice-svg, detslice-with-ops-svg, matchgraph-svg, matchgraph-3d.

Install

Install Stim by QuEra Computing Inc. from the VS Code Marketplace, or run:

code --install-extension QuEraComputing.vscode-stim

For manual installation, download the VSIX from GitHub Releases and use Extensions: Install from VSIX in VS Code or Cursor.

Quick Start

Open a .stim or .dem file. In the editor title bar, click the 📊-button if visible, or in the ...-menu, select Stim: Visualize Circuit.

Toggle between different visualization types in the visualization panel.

Install from source

npm install
npm run build

Then press F5 in VS Code to launch an Extension Development Host with the extension loaded, and open a .stim file.

Building the WebAssembly engine

The compiled engine (wasm/out/stim_diagram.{js,wasm}) is checked in with LFS, so building it is only needed when changing the binding or updating Stim.

Requirements: the Emscripten SDK on your PATH (em++). Stim's source is vendored as a submodule pinned to v1.16.0.

git submodule update --init
source /path/to/emsdk/emsdk_env.sh
npm run build:wasm

The build compiles Stim plus a small Embind shim (wasm/binding.cpp) that exposes the diagram functions. The extension host loads the module, generates the SVG or 3D HTML, and posts it to the webview, which only renders.

Development

npm run watch         # rebuild the extension on change
npm run test:grammar  # TextMate grammar tests
npm run test:wasm     # WebAssembly engine smoke tests
npm run test:engine   # engine wrapper tests

Release

VSIX files are built by GitHub Actions and must not be committed. To publish a release, push a version tag:

git tag v0.1.0
git push origin v0.1.0

The release workflow packages the extension and attaches the generated VSIX to the GitHub release.

To publish to the VS Code Marketplace, upload that VSIX through the QuEra Computing publisher portal. GitHub releases do not automatically publish to the Marketplace. The package version must match the tag and use a numeric major.minor.patch version.

Notes

The interactive 3D viewer loads three.js from a CDN at runtime, so it needs network access. The 2D SVG views work fully offline.

License

The extension's own code is MIT-licensed; see LICENSE. The bundled Stim engine is licensed under Apache License 2.0; see LICENSE-Stim.txt. Third-party components retain their respective licenses. See NOTICE and the included LICENSE-*.txt files for attribution and license terms.