Extension Dev

Detect the stack, find docs, implement the feature, debug. Do NOT just explain — execute the workflow.

Workflow (Execute This)

Step 1: Detect framework and UI stack

Run detection (see references/framework-detection.md):

ls wxt.config.ts plasmo.config.ts vite.config.ts manifest.json 2>/dev/null
cat package.json | grep -E '"wxt|plasmo|crxjs|react|vue|svelte"'

File found	Framework
wxt.config.ts	WXT
package.json has plasmo	Plasmo
vite.config has @crxjs	CRXJS
manifest.json in root, none above	Vanilla

Step 2: Fetch framework docs and style guides

Use docs-seeker skill or web search to find proper docs for the detected stack.

Extension framework docs:

• WXT: https://wxt.dev/ | Plasmo: https://docs.plasmo.com/ | CRXJS: Vite plugin docs
• Chrome APIs: https://developer.chrome.com/docs/extensions/reference/api
• Permissions: https://developer.chrome.com/docs/extensions/reference/permissions-list

UI framework docs (fetch based on detected framework):

Framework	Docs	Style Guide
React	https://react.dev	https://react.dev/learn
Next.js	https://nextjs.org/docs	https://nextjs.org/docs/app
Vue	https://vuejs.org/guide	https://vuejs.org/style-guide
Svelte	https://svelte.dev/docs	https://svelte.dev/docs
SolidJS	https://solidjs.com/docs	https://solidjs.com/guides
Angular	https://angular.dev/guide	https://angular.dev/style-guide

Code style guides (always follow):

• TypeScript: https://google.github.io/styleguide/tsguide.html
• JavaScript: https://google.github.io/styleguide/jsguide.html

Step 3: Implement the feature

Follow framework conventions:

• WXT: add entrypoints in entrypoints/, configure wxt.config.ts
• Plasmo: add pages/tabs/contents, use CSUI for content UI
• CRXJS: standard Vite + manifest-based setup
• Vanilla: edit manifest.json, add JS files directly

For Chrome API usage, check references/chrome-api-quick-reference.md. For messaging between contexts, check references/message-passing-patterns.md.

Step 4: Debug

See references/debugging-guide.md for context-specific DevTools access.

Quick map:

Context	How to inspect
Service worker	chrome://extensions → "inspect" link
Content script	Page DevTools → Console → select extension context
Popup	Right-click popup → Inspect
Options / Side panel	Open page → F12

Step 5: Hot reload setup

Framework	Command	Notes
WXT	pnpm dev	Full HMR, auto-reloads extension
Plasmo	pnpm dev	HMR for popup/content
CRXJS	vite dev	Vite HMR
Vanilla	Manual	Reload at chrome://extensions

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Chrome API Quick Reference (Top 20)

API	Purpose	Permission
chrome.tabs	Query, create, update tabs	tabs
chrome.windows	Manage browser windows	windows
chrome.storage.local	Persist data locally	storage
chrome.storage.sync	Sync data across devices	storage
chrome.storage.session	Session-only data	storage
chrome.action	Toolbar icon, popup, badge	—
chrome.contextMenus	Right-click menu items	contextMenus
chrome.sidePanel	Side panel UI	sidePanel
chrome.notifications	Desktop notifications	notifications
chrome.scripting	Inject scripts/CSS into pages	scripting
chrome.runtime	Messaging, lifecycle, manifest	—
chrome.webRequest	Intercept/modify network requests	webRequest
chrome.declarativeNetRequest	Block/redirect requests declaratively	declarativeNetRequest
chrome.webNavigation	Track page navigation events	webNavigation
chrome.identity	OAuth2, Google Sign-In	identity
chrome.alarms	Schedule periodic tasks	alarms
chrome.commands	Keyboard shortcuts	commands
chrome.cookies	Read/write cookies	cookies
chrome.history	Browser history access	history
chrome.bookmarks	Read/write bookmarks	bookmarks

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Message Passing (Quick Pattern)

One-time (popup → service worker):

// sender
const response = await chrome.runtime.sendMessage({ type: 'GET_DATA' });

// receiver (background)
chrome.runtime.onMessage.addListener((msg, sender, reply) => {
  if (msg.type === 'GET_DATA') { reply({ data: '...' }); return true; }
});

Content script → service worker: same pattern, return true for async. Tab-targeted (background → content):

chrome.tabs.sendMessage(tabId, { type: 'ACTION' });

Full patterns in references/message-passing-patterns.md.

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References

• references/framework-detection.md — detect WXT/Plasmo/CRXJS/vanilla, dev commands
• references/framework-styleguides.md — UI framework docs, style guides, extension framework docs
• references/chrome-api-quick-reference.md — 30+ APIs with permissions and doc links
• references/message-passing-patterns.md — all messaging patterns with TypeScript examples
• references/debugging-guide.md — DevTools per context, common errors, tips

Related Skills

• extension-create — scaffold new extension with WXT
• extension-manifest — generate/validate manifest.json
• extension-test — write and run extension tests
• extension-analyze — analyze existing extension codebase