chrome-extension-wxt

Chrome Extension Development with WXT

Build modern, cross-browser extensions using WXT - the next-generation framework that supports Chrome, Firefox, Edge, Safari, and all Chromium browsers with a single codebase.

When to Use This Skill

Use this skill when:

• Creating a new Chrome/browser extension
• Setting up WXT development environment
• Building extension features (popup, content scripts, background scripts)
• Implementing cross-browser compatibility
• Working with Manifest V3 (mandatory standard as of 2025, V2 deprecated)
• Integrating React 19, Vue, Svelte, or Solid with extensions

Quick Start Workflow

1. Initialize WXT Project

# Create new project with framework of choice
npm create wxt@latest

# Or with specific template
npm create wxt@latest -- --template react-ts
npm create wxt@latest -- --template vue-ts
npm create wxt@latest -- --template svelte-ts

2. Project Structure

WXT uses file-based conventions:

project/
├── entrypoints/              # Auto-discovered entry points
│   ├── background.ts         # Service worker
│   ├── content.ts           # Content script
│   ├── popup.html           # Popup UI
│   └── options.html         # Options page
├── components/              # Auto-imported UI components
├── utils/                   # Auto-imported utilities
├── public/                  # Static assets
│   └── icon/               # Extension icons
├── wxt.config.ts           # Configuration
└── package.json

3. Development Commands

npm run dev              # Start dev server with HMR
npm run build           # Production build
npm run zip             # Package for store submission

Core Entry Points

WXT recognizes entry points by filename in entrypoints/ directory:

Background Script (Service Worker)

// entrypoints/background.ts
export default defineBackground({
  type: 'module',
  persistent: false,

  main() {
    // Listen for extension events
    browser.action.onClicked.addListener((tab) => {
      console.log('Extension clicked', tab);
    });

    // Handle messages
    browser.runtime.onMessage.addListener((message, sender, sendResponse) => {
      // Handle message
      sendResponse({ success: true });
      return true; // Keep channel open for async
    });
  },
});