Playwright (Browser Automation)

General-purpose browser automation skill. Write custom Playwright scripts for any automation task and execute them via the universal executor.

Trigger

Any user request involving browser testing, web automation, screenshots, responsive design checks, form testing, link validation, login flow testing, or any other browser-based task.

Workflow

1. Resolve skill directory

This skill can be installed in different locations (plugin system, manual installation, global, or project-specific). Determine the skill directory based on where this SKILL.md was loaded. Use that path as $SKILL_DIR in all commands below.

2. Setup (first time only)

cd $SKILL_DIR && npm run setup

Installs Playwright and Chromium. Only needed once.

3. Detect dev servers

For localhost testing, always detect running servers first:

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

Result	Action
1 server found	Use it automatically, inform user
Multiple servers found	Ask user which one to test
No servers found	Ask for URL or offer to help start dev server

4. Write the test script

Write custom Playwright code to /tmp/playwright-test-*.js. Never write test files to the skill directory or user's project.

Rules:

• Parameterize URLs — put detected/provided URL in a TARGET_URL constant at top
• Use headless: false by default — only use headless when user explicitly requests it
• Use slowMo: 100 for visibility when helpful

5. Execute

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

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

cd $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();
"

Input method	When to use
File (/tmp/playwright-test-*.js)	Complex tests, responsive checks, anything user might re-run
Inline string	Quick one-off tasks (screenshot, check element, get page title)

6. Report results

Display results in real-time. Browser window is visible for debugging. Test files in /tmp are auto-cleaned by the OS.

Common Patterns

Test a page (multiple viewports)

// /tmp/playwright-test-responsive.js
const { 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.js
const { 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"]', 'test@example.com');
  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.js
const { 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"]', 'john@example.com');
  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.js
const { 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();
})();

Available Helpers

Optional utility functions in lib/helpers.js:

const helpers = require('./lib/helpers');

// Detect running dev servers (use this first)
const servers = await helpers.detectDevServers();
console.log('Found servers:', servers);

// Safe click with retry
await helpers.safeClick(page, 'button.submit', { retries: 3 });

// Safe type with clear
await helpers.safeType(page, '#username', 'testuser');

// Take timestamped screenshot
await helpers.takeScreenshot(page, 'test-result');

// Handle cookie banners
await helpers.handleCookieBanner(page);

// Extract table data
const 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, getting LLM-optimized responses, or adding authentication tokens globally.

Single header (common case):

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

Multiple headers (JSON format):

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

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

Notes

• Each automation is custom-written for the specific request — not limited to pre-built scripts.
• Auto-detects running dev servers to eliminate hardcoded URLs.
• Test scripts written to /tmp for automatic cleanup (no project clutter).
• Code executes with proper module resolution via run.js.
• API_REFERENCE.md loaded only when advanced features are needed.
• Use waitForURL, waitForSelector, waitForLoadState instead of fixed timeouts.
• Always use try-catch for robust automation.
• Playwright not installed? Run 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 is available.
• Element not found? Add wait: await page.waitForSelector('.element', { timeout: 10000 }).