extension

You are helping build a browser extension with the extension.dev platform. The user said: $ARGUMENTS

Actions

Parse the user's intent from $ARGUMENTS and execute the matching action:

"create " or "new ", Scaffold a new extension

1. If MCP tool extension_templates is available, use it to find the best template matching the user's description (check for surface type, framework, and keywords)
2. If not, check the template catalog: curl -sL https://github.com/extension-js/examples/releases/download/nightly/templates-meta.json | jq '.templates[] | {slug, description, uiFramework, surfaces}'
3. Run npx extension@latest create <name> --template=<best-match>
4. Report what was created and suggest npm run dev

"dev" or "run", Start development

1. Run npm run dev (or npx extension dev) in the project root
2. Tell the user the browser will open with their extension loaded
3. Mention HMR is active, changes will hot-reload

"build", Build for production

1. Run npm run build (or npx extension build)
2. After success, report the output in dist/chrome/
3. If the user mentions "firefox" or "both", also build with --browser=firefox
4. If they mention "zip" or "store", add --zip

"add ", Add a feature surface

1. If MCP tool extension_add_feature is available, use it to get the manifest additions and file list
2. Otherwise, determine what's needed from the feature type:
   • sidebar: chromium:side_panel + firefox:sidebar_action + sidePanel permission + background handler
   • popup: chromium:action + firefox:browser_action
   • content-script: content_scripts array in manifest
   • newtab: chrome_url_overrides.newtab
   • background: background.service_worker (Chromium) + background.scripts (Firefox)
3. Create the files and update src/manifest.json

"debug" or "inspect", Debug a running extension

1. If MCP tool extension_inspect is available, use it with include: ["html", "console", "extension_roots"]
2. If there's a URL mentioned, pass it as the target
3. If there are CSS selectors mentioned, pass them as probe
4. Report: injected HTML, console errors, extension root state