Playwright Browser Automation

IMPORTANT - Path Resolution:This skill can be installed in different locations (plugin system, manual installation, global, or project-specific). Before executing any commands, determine the skill directory based on where you loaded this SKILL.md file, and use that path in all commands below. Replace $SKILL_DIR with the actual discovered path.

Common installation paths:

• Plugin system: ~/.claude/plugins/marketplaces/playwright-skill/skills/playwright-skill
• Manual global: ~/.claude/skills/playwright-skill
• Project-specific: <project>/.claude/skills/playwright-skill

Playwright Browser Automation

General-purpose browser automation skill. I'll write custom Playwright code for any automation task you request and execute it via the universal executor.

CRITICAL WORKFLOW - Follow these steps in order:

1. Auto-detect dev servers - For localhost testing, ALWAYS run server detection FIRST:

   cd $SKILL_DIR && node -e "require('./lib/helpers').detectDevServers().then(servers => console.log(JSON.stringify(servers)))"

   • If 1 server found: Use it automatically, inform user
   • If multiple servers found: Ask user which one to test
   • If no servers found: Ask for URL or offer to help start dev server

2. Write scripts to /tmp - NEVER write test files to skill directory; always use /tmp/playwright-test-*.js

3. Use visible browser by default - Always use headless: false unless user specifically requests headless mode

4. Parameterize URLs - Always make URLs configurable via environment variable or constant at top of script

How It Works

1. You describe what you want to test/automate
2. I auto-detect running dev servers (or ask for URL if testing external site)
3. I write custom Playwright code in /tmp/playwright-test-*.js (won't clutter your project)
4. I execute it via: cd $SKILL_DIR && node run.js /tmp/playwright-test-*.js
5. Results displayed in real-time, browser window visible for debugging
6. Test files auto-cleaned from /tmp by your OS

Setup (First Time)

cd $SKILL_DIRnpm run setup

This installs Playwright and Chromium browser. Only needed once.

Execution Pattern

Step 1: Detect dev servers (for localhost testing)

cd $SKILL_DIR && node -e "require('./lib/helpers').detectDevServers().then(s => console.log(JSON.stringify(s)))"

Step 2: Write test script to /tmp with URL parameter

// /tmp/playwright-test-page.jsconst { chromium } = require('playwright');// Parameterized URL (detected or user-provided)const TARGET_URL = 'http://localhost:3001'; // <-- Auto-detected or from user(async () => {  const browser = await chromium.launch({ headless: false });  const page = await browser.newPage();  await page.goto(TARGET_URL);  console.log('Page loaded:', await page.title());  await page.screenshot({ path: '/tmp/screenshot.png', fullPage: true });  console.log('📸 Screenshot saved to /tmp/screenshot.png');  await browser.close();})();

Step 3: Execute from skill directory

cd $SKILL_DIR && node run.js /tmp/playwright-test-page.js

Common Patterns

Test a Page (Multiple Viewports)

// /tmp/playwright-test-responsive.jsconst { chromium } = require('playwright');const TARGET_URL = 'http://localhost:3001'; // Auto-detected(async () => {  const browser = await chromium.launch({ headless: false, slowMo: 100 });  const page = await browser.newPage();  // Desktop test  await page.setViewportSize({ width: 1920, height: 1080 });  await page.goto(TARGET_URL);  console.log('Desktop - Title:', await page.title());  await page.screenshot({ path: '/tmp/desktop.png', fullPage: true });  // Mobile test  await page.setViewportSize({ width: 375, height: 667 });  await page.screenshot({ path: '/tmp/mobile.png', fullPage: true });  await browser.close();})();

Test Login Flow

// /tmp/playwright-test-login.jsconst { chromium } = require('playwright');const TARGET_URL = 'http://localhost:3001'; // Auto-detected(async () => {  const browser = await chromium.launch({ headless: false });  const page = await browser.newPage();  await page.goto(`${TARGET_URL}/login`);  await page.fill('input[name="email"]', '[email protected]');  await page.fill('input[name="password"]', 'password123');  await page.click('button[type="submit"]');  // Wait for redirect  await page.waitForURL('**/dashboard');  console.log('✅ Login successful, redirected to dashboard');  await browser.close();})();

Fill and Submit Form

// /tmp/playwright-test-form.jsconst { chromium } = require('playwright');const TARGET_URL = 'http://localhost:3001'; // Auto-detected(async () => {  const browser = await chromium.launch({ headless: false, slowMo: 50 });  const page = await browser.newPage();  await page.goto(`${TARGET_URL}/contact`);  await page.fill('input[name="name"]', 'John Doe');  await page.fill('input[name="email"]', '[email protected]');  await page.fill('textarea[name="message"]', 'Test message');  await page.click('button[type="submit"]');  // Verify submission  await page.waitForSelector('.success-message');  console.log('✅ Form submitted successfully');  await browser.close();})();

Check for Broken Links

const { chromium } = require('playwright');(async () => {  const browser = await chromium.launch({ headless: false });  const page = await browser.newPage();  await page.goto('http://localhost:3000');  const links = await page.locator('a[href^="http"]').all();  const results = { working: 0, broken: [] };  for (const link of links) {    const href = await link.getAttribute('href');    try {      const response = await page.request.head(href);      if (response.ok()) {        results.working++;      } else {        results.broken.push({ url: href, status: response.status() });      }    } catch (e) {      results.broken.push({ url: href, error: e.message });    }  }  console.log(`✅ Working links: ${results.working}`);  console.log(`❌ Broken links:`, results.broken);  await browser.close();})();

Take Screenshot with Error Handling

const { chromium } = require('playwright');(async () => {  const browser = await chromium.launch({ headless: false });  const page = await browser.newPage();  try {    await page.goto('http://localhost:3000', {      waitUntil: 'networkidle',      timeout: 10000    });    await page.screenshot({      path: '/tmp/screenshot.png',      fullPage: true    });    console.log('📸 Screenshot saved to /tmp/screenshot.png');  } catch (error) {    console.error('❌ Error:', error.message);  } finally {    await browser.close();  }})();

Test Responsive Design

// /tmp/playwright-test-responsive-full.jsconst { chromium } = require('playwright');const TARGET_URL = 'http://localhost:3001'; // Auto-detected(async () => {  const browser = await chromium.launch({ headless: false });  const page = await browser.newPage();  const viewports = [    { name: 'Desktop', width: 1920, height: 1080 },    { name: 'Tablet', width: 768, height: 1024 },    { name: 'Mobile', width: 375, height: 667 }  ];  for (const viewport of viewports) {    console.log(`Testing ${viewport.name} (${viewport.width}x${viewport.height})`);    await page.setViewportSize({      width: viewport.width,      height: viewport.height    });    await page.goto(TARGET_URL);    await page.waitForTimeout(1000);    await page.screenshot({      path: `/tmp/${viewport.name.toLowerCase()}.png`,      fullPage: true    });  }  console.log('✅ All viewports tested');  await browser.close();})();

Inline Execution (Simple Tasks)

For quick one-off tasks, you can execute code inline without creating files:

# Take a quick screenshotcd $SKILL_DIR && node run.js "const browser = await chromium.launch({ headless: false });const page = await browser.newPage();await page.goto('http://localhost:3001');await page.screenshot({ path: '/tmp/quick-screenshot.png', fullPage: true });console.log('Screenshot saved');await browser.close();"

When to use inline vs files:

• Inline: Quick one-off tasks (screenshot, check if element exists, get page title)
• Files: Complex tests, responsive design checks, anything user might want to re-run

Available Helpers

Optional utility functions in lib/helpers.js:

const helpers = require('./lib/helpers');// Detect running dev servers (CRITICAL - use this first!)const servers = await helpers.detectDevServers();console.log('Found servers:', servers);// Safe click with retryawait helpers.safeClick(page, 'button.submit', { retries: 3 });// Safe type with clearawait helpers.safeType(page, '#username', 'testuser');// Take timestamped screenshotawait helpers.takeScreenshot(page, 'test-result');// Handle cookie bannersawait helpers.handleCookieBanner(page);// Extract table dataconst data = await helpers.extractTableData(page, 'table.results');

See lib/helpers.js for full list.

Custom HTTP Headers

Configure custom headers for all HTTP requests via environment variables. Useful for:

• Identifying automated traffic to your backend
• Getting LLM-optimized responses (e.g., plain text errors instead of styled HTML)
• Adding authentication tokens globally

Configuration

Single header (common case):

PW_HEADER_NAME=X-Automated-By PW_HEADER_VALUE=playwright-skill \  cd $SKILL_DIR && node run.js /tmp/my-script.js

Multiple headers (JSON format):

PW_EXTRA_HEADERS='{"X-Automated-By":"playwright-skill","X-Debug":"true"}' \  cd $SKILL_DIR && node run.js /tmp/my-script.js

How It Works

Headers are automatically applied when using helpers.createContext():

const context = await helpers.createContext(browser);const page = await context.newPage();// All requests from this page include your custom headers

For scripts using raw Playwright API, use the injected getContextOptionsWithHeaders():

const context = await browser.newContext(  getContextOptionsWithHeaders({ viewport: { width: 1920, height: 1080 } }));

Advanced Usage

For comprehensive Playwright API documentation, see API_REFERENCE.md:

• Selectors & Locators best practices
• Network interception & API mocking
• Authentication & session management
• Visual regression testing
• Mobile device emulation
• Performance testing
• Debugging techniques
• CI/CD integration

Tips

• CRITICAL: Detect servers FIRST - Always run detectDevServers() before writing test code for localhost testing
• Custom headers - Use PW_HEADER_NAME/PW_HEADER_VALUE env vars to identify automated traffic to your backend
• Use /tmp for test files - Write to /tmp/playwright-test-*.js, never to skill directory or user's project
• Parameterize URLs - Put detected/provided URL in a TARGET_URL constant at the top of every script
• DEFAULT: Visible browser - Always use headless: false unless user explicitly asks for headless mode
• Headless mode - Only use headless: true when user specifically requests "headless" or "background" execution
• Slow down: Use slowMo: 100 to make actions visible and easier to follow
• Wait strategies: Use waitForURL, waitForSelector, waitForLoadState instead of fixed timeouts
• Error handling: Always use try-catch for robust automation
• Console output: Use console.log() to track progress and show what's happening

Troubleshooting

Playwright not installed:

cd $SKILL_DIR && npm run setup

Module not found:Ensure running from skill directory via run.js wrapper

Browser doesn't open:Check headless: false and ensure display available

Element not found:Add wait: await page.waitForSelector('.element', { timeout: 10000 })

Example Usage

User: "Test if the marketing page looks good"Claude: I'll test the marketing page across multiple viewports. Let me first detect running servers...[Runs: detectDevServers()][Output: Found server on port 3001]I found your dev server running on http://localhost:3001[Writes custom automation script to /tmp/playwright-test-marketing.js with URL parameterized][Runs: cd $SKILL_DIR && node run.js /tmp/playwright-test-marketing.js][Shows results with screenshots from /tmp/]

User: "Check if login redirects correctly"Claude: I'll test the login flow. First, let me check for running servers...[Runs: detectDevServers()][Output: Found servers on ports 3000 and 3001]I found 2 dev servers. Which one should I test?- http://localhost:3000- http://localhost:3001User: "Use 3001"[Writes login automation to /tmp/playwright-test-login.js][Runs: cd $SKILL_DIR && node run.js /tmp/playwright-test-login.js][Reports: ✅ Login successful, redirected to /dashboard]

Notes

• Each automation is custom-written for your specific request
• Not limited to pre-built scripts - any browser task possible
• Auto-detects running dev servers to eliminate hardcoded URLs
• Test scripts written to /tmp for automatic cleanup (no clutter)
• Code executes reliably with proper module resolution via run.js
• Progressive disclosure - API_REFERENCE.md loaded only when advanced features needed