VS Code Extension

A bundled VS Code extension opens the SimDeck browser client inside an editor panel and can start or reuse the project daemon when needed. The extension lives in packages/vscode-extension/ and ships pre-bundled with the npm package.

Install

The fastest path is to package the extension from this checkout and install it locally with the VS Code CLI:

npm run package:vscode-extension
npm run install:vscode-extension

This:

1. Builds a .vsix at build/vscode/simdeck-vscode.vsix.
2. Installs it via code --install-extension build/vscode/simdeck-vscode.vsix --force.

If the code command isn't on your PATH, install it from VS Code via Shell Command: Install 'code' command in PATH in the command palette.

Use it

After installing, open the command palette and run:

SimDeck: Open Simulator View

The extension opens a webview panel pointed at a SimDeck daemon URL. If the configured URL is not reachable, the extension runs simdeck ui, reads the returned daemon URL, and loads that URL in the webview.

Two more commands round out the surface:

• SimDeck: Stop Project Daemon — runs simdeck daemon stop for the current workspace.
• SimDeck: Show Output — opens the extension's output channel for debugging.

Settings

All settings live under the simdeck.* namespace in VS Code settings:

Setting	Default	Notes
simdeck.serverUrl	http://127.0.0.1:4310	Preferred URL to try first. If auto-start launches the daemon on a different port, the extension uses the URL returned by simdeck ui.
simdeck.cliPath	empty	Optional explicit path to the simdeck CLI. Empty means: workspace build/, then PATH.
simdeck.port	4310	Preferred port passed to simdeck ui when auto-starting the project daemon.
simdeck.bindAddress	127.0.0.1	Bind address passed to simdeck ui when auto-starting the project daemon.
simdeck.autoStartDaemon	true	If true, the extension starts or reuses the project daemon when opening the simulator view if the preferred URL is not reachable.
simdeck.autoStartServer	true	Deprecated compatibility alias for simdeck.autoStartDaemon.

Resolving the CLI

When the extension needs to start or stop the project daemon it looks for the CLI in this order:

1. The explicit simdeck.cliPath setting.
2. The workspace's build/simdeck (handy when developing on this repo).
3. simdeck from PATH.

If none of those resolve, the extension surfaces an error in the output channel pointing you at this documentation.

Talking to a remote server

Set simdeck.serverUrl to any reachable SimDeck endpoint. The extension is purely a webview shell — it doesn't open WebTransport itself and doesn't ship its own version of the React client. Whatever the daemon serves is what you get.

For LAN-reachable daemons, point the extension at http://<advertise-host>:<port> and disable autoStartDaemon so the extension does not start a local project daemon.

Troubleshooting

• The webview shows a blank panel. Open the output channel; the extension logs the daemon URL returned by simdeck ui and any CLI stderr.
• Auto-start doesn't work. Ensure the resolved cliPath exists and is executable. The extension shows the resolved path in the output channel.
• Stale daemon stays running. Use SimDeck: Stop Project Daemon to run simdeck daemon stop, then reopen the simulator view.