AddFox
  • English

      • Build Better Extensionsfor Developers and AI

      Accelerate your browser extension development. Built on Rsbuild — fast, simple, and free.

      Get StartedView on GitHub
      bash
      $ addfox dev
      [Addfox] 0.0.1 with Rsbuild 0.4.x
      [Addfox] ● Parse config 25ms
      EntryFile
      backgroundapp/background.ts
      contentapp/content/index.ts
      popupapp/popup/index.tsx
      [Addfox] ● Rsbuild ready 136ms
      [Rsbuild] start building app\content\index.ts
      [Rsbuild] ready built in 0.08 s
      [Addfox] ● Dev server http://localhost:3000 2ms
      [Addfox] ● Extension size: 1.24 MB
      🔒chrome-extension://.../welcome.html

      Addfox + React

      Your extension is ready. Happy building!

      For developers

      Hot reload, multi-browser support, and minimal config to help you ship extensions faster.

      Fast HMR

      Dedicated Reloader controls extension updates — not only fast, but both content_script and background achieve ultra-fast HMR.

      ReloaderExtensionAddfoxRsbuild

      Full browser support

      Support for mainstream Chromium-based browsers and Firefox. Auto-detects browser default install path and launches without configuration.

      ChromeFirefoxOperaBrave
      VivaldiArcYandexChromium

      Framework agnostic

      Vanilla, Vue, React, Preact, Svelte, Solid, or React+UnoCSS — use what you like.

      VueReactPreactSvelteSolid
      TypeScriptJavaScript

      Content UI support

      Built-in createContentUI method for easy integration of Iframe, ShadowDom, and native content.

      https://example.com/article
      Translate
      Original
      Selected text...
      Translation
      Translated result
      EN → ZH

      Rstack Ecosystem

      Built-in support for Rsdoctor and Rstest to quickly complete bundle analysis, unit and e2e testing.

      Zip on build

      Build automatically outputs an extension zip package for easy installation and distribution.

      For AI

      Structured meta, terminal error output, and Skills — so AI can understand and work with your extension.

      llms.txt and markdown metadata support

      Provides clear extension info, error details, and prompts to help AI agents develop.

      AIllms.txtMmeta.md!error.mdAI Agent

      AI-friendly error monitor

      Enable terminal error output with --debug. Capture all extension errors without browser DevTools, so you can Ask AI directly in any editor.

      bash
      $ addfox dev --debug
      error
      --- BEGIN AI PROMPT ---
      You are a frontend and browser extension development expert, proficient with the Addfox framework.
      This is an Addfox-based browser extension runtime error (MV3).
      Before proposing fixes:
      1) Read `.addfox/llms.txt` first.
      2) Apply the `addfox-debugging` skills to analyze this report (and `.addfox/error.md` / `.addfox/meta.md` if available).
      --- END AI PROMPT ---
      --- Addfox extension error ---
      bundler: rsbuild
      front-end-framework: React
      entry: content
      type: error
      time: 2026/3/21 20:58:51
      message: fff is not defined
      location: chrome-extension://fbnnalickbkocmeokpogajmocmcejemg/content/index.js:2966:1
      stack:
      ReferenceError: fff is not defined
      at ./app/content/index.ts (chrome-extension://fbnnalickbkocmeokpogajmocmcejemg/content/index.js:1635:45)
      at __webpack_require__ (chrome-extension://fbnnalickbkocmeokpogajmocmcejemg/content/index.js:2962:29)
      at chrome-extension://fbnnalickbkocmeokpogajmocmcejemg/content/index.js:4125:27
      at chrome-extension://fbnnalickbkocmeokpogajmocmcejemg/content/index.js:4126:3
      ---------------------------
      --- BEGIN AI PROMPT ---
      You are a frontend and browser extension development expert, proficient with the Addfox framework.
      This is an Addfox-based browser extension runtime error (MV3).
      Before proposing fixes:
      1) Read `.addfox/llms.txt` first.
      2) Apply the `addfox-debugging` skills to analyze this report (and `.addfox/error.md` / `.addfox/meta.md` if available).
      --- END AI PROMPT ---
      --- Addfox extension error ---
      bundler: rsbuild
      front-end-framework: React
      entry: content
      type: error
      time: 2026/3/21 20:58:51
      message: fff is not defined
      location: chrome-extension://fbnnalickbkocmeokpogajmocmcejemg/content/index.js:2966:1
      stack:
      ReferenceError: fff is not defined
      at ./app/content/index.ts (chrome-extension://fbnnalickbkocmeokpogajmocmcejemg/content/index.js:1635:45)
      at __webpack_require__ (chrome-extension://fbnnalickbkocmeokpogajmocmcejemg/content/index.js:2962:29)
      at chrome-extension://fbnnalickbkocmeokpogajmocmcejemg/content/index.js:4125:27
      at chrome-extension://fbnnalickbkocmeokpogajmocmcejemg/content/index.js:4126:3
      ---------------------------

      Skills support

      Extensible Skills to support Agents and automation.

      migrate-to-addfox
      addfox-best-practices
      extension-functions-best-practices
      addfox-debugging
      addfox-testing
      migrate-to-addfox
      addfox-best-practices
      extension-functions-best-practices
      addfox-debugging
      addfox-testing
      migrate-to-addfox
      addfox-best-practices
      extension-functions-best-practices
      addfox-debugging
      addfox-testing
      migrate-to-addfox
      addfox-best-practices
      extension-functions-best-practices
      addfox-debugging
      addfox-testing
      addfox-debugging
      addfox-testing
      addfox-best-practices
      migrate-to-addfox
      extension-functions-best-practices
      addfox-debugging
      addfox-testing
      addfox-best-practices
      migrate-to-addfox
      extension-functions-best-practices
      addfox-debugging
      addfox-testing
      addfox-best-practices
      migrate-to-addfox
      extension-functions-best-practices
      addfox-debugging
      addfox-testing
      addfox-best-practices
      migrate-to-addfox
      extension-functions-best-practices

      What Creator Says

      "
      Gomi
      Gomi
      Creator of VideoRoll and AddFox
      I'm Gomi, the creator of Video Roll, a browser extension featured on both Chrome Web Store and Edge with over 35K users. Despite its success, I still felt unsatisfied with the extension development experience. After trying Parcel, Vite, and other tools, I decided to tackle the pain points myself. Even with excellent solutions like WXT and Plasmo available, I didn't want to reinvent the wheel. The speed of Rsbuild and the AI-friendly development paradigm fascinated me, so I created Addfox.

      Frequently Asked Questions

      Quick answers to common questions about Addfox

      Yes, Addfox is fully open source under the MIT license. You can view the source code on GitHub, contribute to the project, or fork it for your own needs.
      Currently, Addfox focuses on Chromium-based browsers (Chrome, Edge, Arc, Brave, etc.) and Firefox. Safari support is not available at this time due to its different extension API and packaging requirements.
      Absolutely! Addfox is framework-agnostic and works with React, Vue, Preact, Svelte, Solid, and vanilla JavaScript/TypeScript. You can use your preferred framework with minimal configuration.
      WXT, Plasmo, and Extension.js are all excellent choices that have greatly advanced the extension development ecosystem. WXT brings the power of Vite and a well-designed plugin system; Plasmo offers comprehensive cloud integration and a polished developer experience; Extension.js provides simplicity and ease of use. Addfox takes a different approach: built on Rsbuild for exceptional build speed, designed specifically for AI-assisted development with structured metadata and terminal error output, and offering maximum flexibility through minimal conventions—you can organize your code however you prefer while still getting out-of-the-box HMR and multi-browser support.