extension-devlisted

Build, debug, and publish cross-browser extensions (Chrome, Edge, Firefox, and any Chromium- or Gecko-based browser such as Brave, Opera, Vivaldi, Yandex, Waterfox, or LibreWolf, plus Safari) with the extension.dev framework. Use this skill whenever the user mentions browser extensions, Chrome extensions, Firefox add-ons, Safari web extensions, WebExtensions, Manifest V3, manifest.json, content scripts, service workers, side panels, popups, options pages, chrome.* or browser.* APIs, or publishing to the Chrome Web Store or Firefox Add-ons, even if they never name extension.dev or Extension.js explicitly. Also use it when debugging why an extension does not load, inject, or update.
extensiondev/skill · ★ 0 · AI & Automation · score 73

Install: claude install-skill extensiondev/skill

# Cross-Browser Extension Development This skill covers the full lifecycle of a browser extension built on the [extension.dev](https://extension.dev) platform (powered by the open-source [Extension.js](https://extension.js.org) framework): scaffold from a template, develop with hot reload, verify against a live browser, build per browser, and publish. Two companions do the heavy lifting. Prefer them over guessing: - **`@extension.dev/mcp`** (MCP server): 30 tools for scaffolding, building, live DOM inspection, log streaming, storage access, asserting expectations against a running extension (`extension_assert`), publishing, headless project creation (`extension_project_create`, run after the code is pushed to GitHub and before `extension_auth` against the new project), and headless release promotion. If its `extension_*` tools are available in the session, use them. - **`extension` CLI**: the local loop has a CLI path (`npx extension@latest <command>`), and only the local loop. The commands are `create`, `dev`, `start`, `preview`, `build`, `logs`, `inspect`, `eval`, `storage`, `reload`, `open`, `doctor`, `publish`, `install` and `uninstall`. Use them when the MCP server is not connected. - **Everything else is MCP-only.** Do not invent a CLI command for a tool that has none, because the shell will not tell you it was never there. No `extension` command exists for `extension_assert`, `extension_auth`, `extension_project_create`, `extension_release_