Browser - Code-First Browser Automation
Browser automation and web verification using code-first Playwright.
🔌 File-Based MCP
This skill is a file-based MCP - a code-first API wrapper that replaces token-heavy MCP protocol calls.
Why file-based? Filter data in code BEFORE returning to model context = 99%+ token savings.
Architecture: See $PAI_DIR/skills/CORE/SYSTEM/DOCUMENTATION/FileBasedMCPs.md
Quick Start
import { PlaywrightBrowser } from '$PAI_DIR/skills/Browser/index.ts'
const browser = new PlaywrightBrowser()
await browser.launch()
await browser.navigate('https://example.com')
await browser.screenshot({ path: 'screenshot.png' })
await browser.close()
Why This Approach:
- MCP loads ~13,700 tokens at startup
- Code-first loads ~50-200 tokens per operation
- Full Playwright API access, not limited to 21 MCP tools
Voice Notification
When executing a Browser workflow, do BOTH:
Send voice notification:
curl -s -X POST http://localhost:8888/notify \ -H "Content-Type: application/json" \ -d '{"message": "Running the Browser workflow"}' \ > /dev/null 2>&1 &Output text notification:
Running the **Browser** workflow...
Workflow Routing
| Trigger | Workflow |
|---|---|
| Navigate to URL, take screenshot | Workflows/Screenshot.md |
| Verify page loads correctly | Workflows/VerifyPage.md |
| Fill forms, interact with page | Workflows/Interact.md |
| Extract page content | Workflows/Extract.md |
API Reference
Navigation
await browser.launch(options?) // Start browser
await browser.navigate(url) // Go to URL
await browser.goBack() // History back
await browser.goForward() // History forward
await browser.reload() // Refresh
browser.getUrl() // Current URL
await browser.getTitle() // Page title
await browser.close() // Shut down browser
Capture
await browser.screenshot({ path, fullPage, selector })
await browser.getVisibleText(selector?)
await browser.getVisibleHtml({ removeScripts, minify })
await browser.savePdf(path, { format })
await browser.getAccessibilityTree()
Network Monitoring
browser.getNetworkLogs(options?) // Get all network requests/responses
browser.getNetworkStats() // Get summary statistics
browser.clearNetworkLogs() // Clear captured logs
Dialog Handling
browser.setDialogHandler(auto, response?) // Configure auto-handling
browser.getPendingDialog() // Get current dialog info
await browser.handleDialog(action, promptText?) // Handle dialog manually
Tab Management
browser.getTabs() // List all open tabs
await browser.newTab(url?) // Open new tab
await browser.switchTab(index) // Switch to tab by index
await browser.closeTab() // Close current tab
Interaction
await browser.click(selector)
await browser.hover(selector)
await browser.fill(selector, value)
await browser.type(selector, text, delay?)
await browser.select(selector, value)
await browser.pressKey(key, selector?)
await browser.drag(source, target)
await browser.uploadFile(selector, path)
Waiting
await browser.waitForSelector(selector, { state, timeout })
await browser.waitForText(text, { state, timeout })
await browser.waitForNavigation({ url, timeout })
await browser.waitForNetworkIdle(timeout?)
await browser.wait(ms)
await browser.waitForResponse(urlPattern)
JavaScript
await browser.evaluate(script)
browser.getConsoleLogs({ type, search, limit, clear })
await browser.setUserAgent(ua)
Viewport
await browser.resize(width, height)
await browser.setDevice('iPhone 14')
iFrame
await browser.iframeClick(iframeSelector, elementSelector)
await browser.iframeFill(iframeSelector, elementSelector, value)
VERIFY Phase Integration
The Browser skill is MANDATORY for VERIFY phase of web changes.
Before claiming ANY web change is "live" or "working":
- Launch browser
- Navigate to the EXACT URL
- Verify the EXACT element that changed
- Take screenshot as evidence
- Close browser
// VERIFY Phase Pattern
import { PlaywrightBrowser } from '$PAI_DIR/skills/Browser/index.ts'
const browser = new PlaywrightBrowser()
await browser.launch({ headless: true })
await browser.navigate('https://example.com/changed-page')
await browser.waitForSelector('.changed-element')
const text = await browser.getVisibleText('.changed-element')
await browser.screenshot({ path: '/tmp/verify.png' })
await browser.close()
console.log(`Verified: "${text}"`)
If you haven't LOOKED at the rendered page, you CANNOT claim it works.
CLI Tool
Location: Tools/Browse.ts
# Open URL in visible browser
bun run $PAI_DIR/skills/Browser/Tools/Browse.ts open <url>
# Take screenshot
bun run $PAI_DIR/skills/Browser/Tools/Browse.ts screenshot <url> [path]
# Verify element exists
bun run $PAI_DIR/skills/Browser/Tools/Browse.ts verify <url> <selector>
Examples:
bun run $PAI_DIR/skills/Browser/Tools/Browse.ts open https://danielmiessler.com
bun run $PAI_DIR/skills/Browser/Tools/Browse.ts screenshot https://example.com /tmp/shot.png
bun run $PAI_DIR/skills/Browser/Tools/Browse.ts verify https://example.com "body"
Examples
Verify Page Loads
bun $PAI_DIR/skills/Browser/examples/verify-page.ts https://danielmiessler.com
Take Screenshot
bun $PAI_DIR/skills/Browser/examples/screenshot.ts https://example.com screenshot.png
Fill Form
const browser = new PlaywrightBrowser()
await browser.launch()
await browser.navigate('https://example.com/form')
await browser.fill('#email', 'test@example.com')
await browser.fill('#password', 'secret')
await browser.click('button[type="submit"]')
await browser.waitForNavigation()
await browser.close()
Alternative Implementations (Reference Only)
Option A: Playwright MCP (Microsoft Official)
# npx @playwright/mcp@latest
# 25K GitHub stars, uses accessibility tree
# Pro: Official Microsoft support, well-maintained
# Con: 13,700 tokens at startup
Option B: Chrome DevTools MCP (Google Official)
# npx @anthropic/chrome-devtools-mcp
# Best debugging capabilities, CDP protocol
# Pro: Deep browser internals access
# Con: Chrome-only, complex setup
Option C: claude --chrome (Native Anthropic)
# claude --chrome
# Simplest option - built into Claude Code
# Pro: Zero configuration, native integration
# Con: Limited API compared to Playwright
Option D: Stagehand (Browserbase)
# npx stagehand
# 19.9K stars, won Anthropic hackathon
# Pro: AI-native actions (act, extract, observe)
# Con: Emerging, less mature than Playwright
Token Savings Comparison
| Approach | Tokens | Notes |
|---|---|---|
| Playwright MCP | ~13,700 | Loaded at startup, always |
| Code-first | ~50-200 | Only what you use |
| Savings | 99%+ | Per operation |
Full Documentation
CLI Tool: Tools/Browse.ts
Implementation: README.md
API Reference: index.ts
Examples: examples/