# Browser Extension Architecture Questions

## Target Browsers

1. **Target browser(s):**
   - Chrome (most common)
   - Firefox
   - Edge (Chromium-based)
   - Safari
   - Opera
   - Brave
   - Multiple browsers (cross-browser)

2. **Manifest version:**
   - Manifest V3 (current standard, required for Chrome Web Store)
   - Manifest V2 (legacy, being phased out)
   - Both (transition period)

3. **Cross-browser compatibility:**
   - Chrome/Edge only (same codebase)
   - Chrome + Firefox (minor differences)
   - All major browsers (requires polyfills/adapters)

## Extension Type and Architecture

4. **Primary extension type:**
   - Browser Action (icon in toolbar)
   - Page Action (icon in address bar, page-specific)
   - Content Script (runs on web pages)
   - DevTools Extension (adds features to browser DevTools)
   - New Tab Override
   - Bookmarks/History extension
   - Multiple components

5. **Extension components needed:**
   - Background script/Service Worker (always running logic)
   - Content scripts (inject into web pages)
   - Popup UI (click toolbar icon)
   - Options page (settings/configuration)
   - Side panel (persistent panel, MV3)
   - DevTools page
   - New Tab page

6. **Content script injection:**
   - All pages (matches: <all_urls>)
   - Specific domains (matches: \*.example.com)
   - User-activated (inject on demand)
   - Not needed

## UI and Framework

7. **UI framework:**
   - Vanilla JS (no framework)
   - React
   - Vue
   - Svelte
   - Preact (lightweight React)
   - Web Components
   - Other: **\_\_\_**

8. **Build tooling:**
   - Webpack
   - Vite
   - Rollup
   - Parcel
   - esbuild
   - WXT (extension-specific)
   - Plasmo (extension framework)
   - None (plain JS)

9. **CSS framework:**
   - Tailwind CSS
   - CSS Modules
   - Styled Components
   - Plain CSS
   - Sass/SCSS
   - None (minimal styling)

10. **Popup UI:**
    - Simple (HTML + CSS)
    - Interactive (full app)
    - None (no popup)

11. **Options page:**
    - Simple form (HTML)
    - Full settings UI (framework-based)
    - Embedded in popup
    - None (no settings)

## Permissions

12. **Storage permissions:**
    - chrome.storage.local (local storage)
    - chrome.storage.sync (sync across devices)
    - IndexedDB
    - None (no data persistence)

13. **Host permissions (access to websites):**
    - Specific domains only
    - All URLs (<all_urls>)
    - ActiveTab only (current tab when clicked)
    - Optional permissions (user grants on demand)

14. **API permissions needed:**
    - tabs (query/manipulate tabs)
    - webRequest (intercept network requests)
    - cookies
    - history
    - bookmarks
    - downloads
    - notifications
    - contextMenus (right-click menu)
    - clipboardWrite/Read
    - identity (OAuth)
    - Other: **\_\_\_**

15. **Sensitive permissions:**
    - webRequestBlocking (modify requests, requires justification)
    - declarativeNetRequest (MV3 alternative)
    - None

## Data and Storage

16. **Data storage:**
    - chrome.storage.local
    - chrome.storage.sync (synced across devices)
    - IndexedDB
    - localStorage (limited, not recommended)
    - Remote storage (own backend)
    - Multiple storage types

17. **Storage size:**
    - Small (< 100KB)
    - Medium (100KB - 5MB, storage.sync limit)
    - Large (> 5MB, need storage.local or IndexedDB)

18. **Data sync:**
    - Sync across user's devices (chrome.storage.sync)
    - Local only (storage.local)
    - Custom backend sync

## Communication

19. **Message passing (internal):**
    - Content script <-> Background script
    - Popup <-> Background script
    - Content script <-> Content script
    - Not needed

20. **Messaging library:**
    - Native chrome.runtime.sendMessage
    - Wrapper library (webext-bridge, etc.)
    - Custom messaging layer

21. **Backend communication:**
    - REST API
    - WebSocket
    - GraphQL
    - Firebase/Supabase
    - None (client-only extension)

## Web Integration

22. **DOM manipulation:**
    - Read DOM (observe, analyze)
    - Modify DOM (inject, hide, change elements)
    - Both
    - None (no content scripts)

23. **Page interaction method:**
    - Content scripts (extension context)
    - Injected scripts (page context, access page variables)
    - Both (communicate via postMessage)

24. **CSS injection:**
    - Inject custom styles
    - Override site styles
    - None

25. **Network request interception:**
    - Read requests (webRequest)
    - Block/modify requests (declarativeNetRequest in MV3)
    - Not needed

## Background Processing

26. **Background script type (MV3):**
    - Service Worker (MV3, event-driven, terminates when idle)
    - Background page (MV2, persistent)

27. **Background tasks:**
    - Event listeners (tabs, webRequest, etc.)
    - Periodic tasks (alarms)
    - Message routing (popup <-> content scripts)
    - API calls
    - None

28. **Persistent state (MV3 challenge):**
    - Store in chrome.storage (service worker can terminate)
    - Use alarms for periodic tasks
    - Not applicable (MV2 or stateless)

## Authentication

29. **User authentication:**
    - OAuth (chrome.identity API)
    - Custom login (username/password with backend)
    - API key
    - No authentication needed

30. **OAuth provider:**
    - Google
    - GitHub
    - Custom OAuth server
    - Not using OAuth

## Distribution

31. **Distribution method:**
    - Chrome Web Store (public)
    - Chrome Web Store (unlisted)
    - Firefox Add-ons (AMO)
    - Edge Add-ons Store
    - Self-hosted (enterprise, sideload)
    - Multiple stores

32. **Pricing model:**
    - Free
    - Freemium (basic free, premium paid)
    - Paid (one-time purchase)
    - Subscription
    - Enterprise licensing

33. **In-extension purchases:**
    - Via web (redirect to website)
    - Stripe integration
    - No purchases

## Privacy and Security

34. **User privacy:**
    - No data collection
    - Anonymous analytics
    - User data collected (with consent)
    - Data sent to server

35. **Content Security Policy (CSP):**
    - Default CSP (secure)
    - Custom CSP (if needed for external scripts)

36. **External scripts:**
    - None (all code bundled)
    - CDN scripts (requires CSP relaxation)
    - Inline scripts (avoid in MV3)

37. **Sensitive data handling:**
    - Encrypt stored data
    - Use native credential storage
    - No sensitive data

## Testing

38. **Testing approach:**
    - Manual testing (load unpacked)
    - Unit tests (Jest, Vitest)
    - E2E tests (Puppeteer, Playwright)
    - Cross-browser testing
    - Minimal testing

39. **Test automation:**
    - Automated tests in CI
    - Manual testing only

## Updates and Deployment

40. **Update strategy:**
    - Auto-update (store handles)
    - Manual updates (enterprise)

41. **Versioning:**
    - Semantic versioning (1.2.3)
    - Chrome Web Store version requirements

42. **CI/CD:**
    - GitHub Actions
    - GitLab CI
    - Manual builds/uploads
    - Web Store API (automated publishing)

## Features

43. **Context menu integration:**
    - Right-click menu items
    - Not needed

44. **Omnibox integration:**
    - Custom omnibox keyword
    - Not needed

45. **Browser notifications:**
    - Chrome notifications API
    - Not needed

46. **Keyboard shortcuts:**
    - chrome.commands API
    - Not needed

47. **Clipboard access:**
    - Read clipboard
    - Write to clipboard
    - Not needed

48. **Side panel (MV3):**
    - Persistent side panel UI
    - Not needed

49. **DevTools integration:**
    - Add DevTools panel
    - Not needed

50. **Internationalization (i18n):**
    - Multiple languages
    - English only

## Analytics and Monitoring

51. **Analytics:**
    - Google Analytics (with privacy considerations)
    - PostHog
    - Mixpanel
    - Custom analytics
    - None

52. **Error tracking:**
    - Sentry
    - Bugsnag
    - Custom error logging
    - None

53. **User feedback:**
    - In-extension feedback form
    - External form (website)
    - Email/support
    - None

## Performance

54. **Performance considerations:**
    - Minimal memory footprint
    - Lazy loading
    - Efficient DOM queries
    - Not a priority

55. **Bundle size:**
    - Keep small (< 1MB)
    - Moderate (1-5MB)
    - Large (> 5MB, media/assets)

## Compliance and Review

56. **Chrome Web Store review:**
    - Standard review (automated + manual)
    - Sensitive permissions (extra scrutiny)
    - Not yet submitted

57. **Privacy policy:**
    - Required (collecting data)
    - Not required (no data collection)
    - Already prepared

58. **Code obfuscation:**
    - Minified only
    - Not allowed (stores require readable code)
    - Using source maps
