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:
-
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
-
Write scripts to /tmp - NEVER write test files to skill directory; always use /tmp/playwright-test-*.js
-
Use visible browser by default - Always use headless: false unless user specifically requests headless mode
-
Parameterize URLs - Always make URLs configurable via environment variable or constant at top of script
How It Works
- You describe what you want to test/automate
- I auto-detect running dev servers (or ask for URL if testing external site)
- I write custom Playwright code in
/tmp/playwright-test-*.js (won't clutter your project)
- I execute it via:
cd $SKILL_DIR && node run.js /tmp/playwright-test-*.js
- Results displayed in real-time, browser window visible for debugging
- Test files auto-cleaned from /tmp by your OS
Setup (First Time)
cd $SKILL_DIR
npm 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.js
const { 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 $SKILL_DIR && node run.js /tmp/playwright-test-page.js
Common Patterns
Test a Page (Multiple Viewports)
// /tmp/playwright-test-responsive.js
const { chromium } = require('playwright');
const TARGET_URL = 'http://localhost:3001'; // Auto-detected
(async () => {
const browser = await chromium.launch({ headless: false, slowMo: 100 });
const page = await browser.newPage();
// Desktop test
await page.setViewportSize({ width: 1920, height: 1080 });
await page.goto(TARGET_URL);
console.log('Desktop - Title:', await page.title());
await page.screenshot({ path: '/tmp/desktop.png', fullPage: true });
// Mobile test
await page.setViewportSize({ width: 375, height: 667 });
await page.screenshot({ path: '/tmp/mobile.png', fullPage: true });
await browser.close();
})();
Test Login Flow
// /tmp/playwright-test-login.js
const { chromium } = require('playwright');
const TARGET_URL = 'http://localhost:3001'; // Auto-detected
(async () => {
const browser = await chromium.launch({ headless: false });
const page = await browser.newPage();
await page.goto(`${TARGET_URL}/login`);
await page.fill('input[name="email"]', '[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.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"]', '[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.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();
})();
Inline Execution (Simple Tasks)
For quick one-off tasks, you can execute code inline without creating files:
# Take a quick screenshot
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();
"
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 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 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
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:3001
User: "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
