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-py-skill/skills/playwright-py-skill
Manual global: ~/.claude/skills/playwright-py-skill
Project-specific: <project>/.claude/skills/playwright-py-skill

CRITICAL: Sequential Tool Usage

When writing and executing Playwright scripts, ALWAYS use Write and Bash tools in separate responses:

❌ DO NOT use parallel execution (causes race condition):

Write: create /tmp/playwright-test.py
Bash: uv run run.py /tmp/playwright-test.py  <-- Executes before Write completes!

✅ ALWAYS use sequential execution:

Response 1: Write /tmp/playwright-test.py
Response 2: Bash: cd $SKILL_DIR && uv run run.py /tmp/playwright-test.py

This prevents race conditions where Bash executes before the file is fully written.

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 && uv run python -c "from lib.helpers import detect_dev_servers; import asyncio, json; print(json.dumps(asyncio.run(detect_dev_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-*.py
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-*.py (won't clutter your project)
I execute it via: cd $SKILL_DIR && uv run run.py /tmp/playwright-test-*.py
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
uv run run.py --help

This will automatically install Playwright via PEP 723 metadata. Chromium browser must already be installed (correct version for Playwright 1.56.0).

Execution Pattern

Step 1: Detect dev servers (for localhost testing)

cd $SKILL_DIR && uv run python -c "from lib.helpers import detect_dev_servers; import asyncio, json; print(json.dumps(asyncio.run(detect_dev_servers())))"

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

#!/usr/bin/env python3
# /// script
# requires-python = ">=3.10"
# dependencies = [
#     "playwright==1.56.0",
# ]
# ///
# /tmp/playwright-test-page.py
from playwright.sync_api import sync_playwright

# Parameterized URL (detected or user-provided)
TARGET_URL = 'http://localhost:3001'  # <-- Auto-detected or from user

with sync_playwright() as p:
    browser = p.chromium.launch(headless=False)
    page = browser.new_page()

    page.goto(TARGET_URL)
    print('Page loaded:', page.title())

    page.screenshot(path='/tmp/screenshot.png', full_page=True)
    print('📸 Screenshot saved to /tmp/screenshot.png')

    browser.close()

Step 3: Execute from skill directory

cd $SKILL_DIR && uv run run.py /tmp/playwright-test-page.py

Common Patterns

Test a Page (Multiple Viewports)

#!/usr/bin/env python3
# /// script
# requires-python = ">=3.10"
# dependencies = [
#     "playwright==1.56.0",
# ]
# ///
# /tmp/playwright-test-responsive.py
from playwright.sync_api import sync_playwright

TARGET_URL = 'http://localhost:3001'  # Auto-detected

with sync_playwright() as p:
    browser = p.chromium.launch(headless=False, slow_mo=100)
    page = browser.new_page()

    # Desktop test
    page.set_viewport_size({'width': 1920, 'height': 1080})
    page.goto(TARGET_URL)
    print('Desktop - Title:', page.title())
    page.screenshot(path='/tmp/desktop.png', full_page=True)

    # Mobile test
    page.set_viewport_size({'width': 375, 'height': 667})
    page.screenshot(path='/tmp/mobile.png', full_page=True)

    browser.close()

Test Login Flow

#!/usr/bin/env python3
# /// script
# requires-python = ">=3.10"
# dependencies = [
#     "playwright==1.56.0",
# ]
# ///
# /tmp/playwright-test-login.py
from playwright.sync_api import sync_playwright

TARGET_URL = 'http://localhost:3001'  # Auto-detected

with sync_playwright() as p:
    browser = p.chromium.launch(headless=False)
    page = browser.new_page()

    page.goto(f'{TARGET_URL}/login')

    page.fill('input[name="email"]', 'test@example.com')
    page.fill('input[name="password"]', 'password123')
    page.click('button[type="submit"]')

    # Wait for redirect
    page.wait_for_url('**/dashboard')
    print('✅ Login successful, redirected to dashboard')

    browser.close()

Fill and Submit Form

#!/usr/bin/env python3
# /// script
# requires-python = ">=3.10"
# dependencies = [
#     "playwright==1.56.0",
# ]
# ///
# /tmp/playwright-test-form.py
from playwright.sync_api import sync_playwright

TARGET_URL = 'http://localhost:3001'  # Auto-detected

with sync_playwright() as p:
    browser = p.chromium.launch(headless=False, slow_mo=50)
    page = browser.new_page()

    page.goto(f'{TARGET_URL}/contact')

    page.fill('input[name="name"]', 'John Doe')
    page.fill('input[name="email"]', 'john@example.com')
    page.fill('textarea[name="message"]', 'Test message')
    page.click('button[type="submit"]')

    # Verify submission
    page.wait_for_selector('.success-message')
    print('✅ Form submitted successfully')

    browser.close()

Check for Broken Links

#!/usr/bin/env python3
# /// script
# requires-python = ">=3.10"
# dependencies = [
#     "playwright==1.56.0",
# ]
# ///
from playwright.sync_api import sync_playwright

with sync_playwright() as p:
    browser = p.chromium.launch(headless=False)
    page = browser.new_page()

    page.goto('http://localhost:3000')

    links = page.locator('a[href^="http"]').all()
    results = {'working': 0, 'broken': []}

    for link in links:
        href = link.get_attribute('href')
        try:
            response = page.request.head(href)
            if response.ok:
                results['working'] += 1
            else:
                results['broken'].append({'url': href, 'status': response.status})
        except Exception as e:
            results['broken'].append({'url': href, 'error': str(e)})

    print(f'✅ Working links: {results["working"]}')
    print(f'❌ Broken links:', results['broken'])

    browser.close()

Take Screenshot with Error Handling

#!/usr/bin/env python3
# /// script
# requires-python = ">=3.10"
# dependencies = [
#     "playwright==1.56.0",
# ]
# ///
from playwright.sync_api import sync_playwright

with sync_playwright() as p:
    browser = p.chromium.launch(headless=False)
    page = browser.new_page()

    try:
        page.goto('http://localhost:3000', wait_until='networkidle', timeout=10000)

        page.screenshot(path='/tmp/screenshot.png', full_page=True)

        print('📸 Screenshot saved to /tmp/screenshot.png')
    except Exception as error:
        print(f'❌ Error: {error}')
    finally:
        browser.close()

Test Responsive Design

#!/usr/bin/env python3
# /// script
# requires-python = ">=3.10"
# dependencies = [
#     "playwright==1.56.0",
# ]
# ///
# /tmp/playwright-test-responsive-full.py
from playwright.sync_api import sync_playwright

TARGET_URL = 'http://localhost:3001'  # Auto-detected

with sync_playwright() as p:
    browser = p.chromium.launch(headless=False)
    page = browser.new_page()

    viewports = [
        {'name': 'Desktop', 'width': 1920, 'height': 1080},
        {'name': 'Tablet', 'width': 768, 'height': 1024},
        {'name': 'Mobile', 'width': 375, 'height': 667},
    ]

    for viewport in viewports:
        print(f'Testing {viewport["name"]} ({viewport["width"]}x{viewport["height"]})')

        page.set_viewport_size({'width': viewport['width'], 'height': viewport['height']})

        page.goto(TARGET_URL)
        page.wait_for_timeout(1000)

        page.screenshot(path=f'/tmp/{viewport["name"].lower()}.png', full_page=True)

    print('✅ All viewports tested')
    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 && uv run run.py "
with sync_playwright() as p:
    browser = p.chromium.launch(headless=False)
    page = browser.new_page()
    page.goto('http://localhost:3001')
    page.screenshot(path='/tmp/quick-screenshot.png', full_page=True)
    print('Screenshot saved')
    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.py:

from lib.helpers import *

# Detect running dev servers (CRITICAL - use this first!)
servers = await detect_dev_servers()
print('Found servers:', servers)

# Safe click with retry
safe_click(page, 'button.submit', retries=3)

# Safe type with clear
safe_type(page, '#username', 'testuser')

# Take timestamped screenshot
take_screenshot(page, 'test-result')

# Handle cookie banners
handle_cookie_banner(page)

# Extract table data
data = extract_table_data(page, 'table.results')

See lib/helpers.py 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-py-skill \
  cd $SKILL_DIR && uv run run.py /tmp/my-script.py

Multiple headers (JSON format):

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

How It Works

Headers are automatically applied when using create_context():

context = create_context(browser)
page = context.new_page()
# All requests from this page include your custom headers

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

context = browser.new_context(
    get_context_options_with_headers({'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 detect_dev_servers() 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-*.py, 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 slow_mo=100 to make actions visible and easier to follow
Wait strategies: Use wait_for_url, wait_for_selector, wait_for_load_state instead of fixed timeouts
Error handling: Always use try-catch for robust automation
Console output: Use print() to track progress and show what's happening

Troubleshooting

Playwright not installed:

cd $SKILL_DIR && uv run run.py --help
# This will auto-install playwright==1.56.0 via PEP 723

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

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

Element not found: Add wait: page.wait_for_selector('.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: detect_dev_servers()]
[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.py with URL parameterized]
[Runs: cd $SKILL_DIR && uv run run.py /tmp/playwright-test-marketing.py]
[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: detect_dev_servers()]
[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.py]
[Runs: cd $SKILL_DIR && uv run run.py /tmp/playwright-test-login.py]
[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.py
Progressive disclosure - API_REFERENCE.md loaded only when advanced features needed
Chromium browser must be installed separately (correct version for Playwright 1.56.0)

playwright-py-skill

CRITICAL: Sequential Tool Usage

Playwright Browser Automation

How It Works

Setup (First Time)

Execution Pattern

Common Patterns

Test a Page (Multiple Viewports)

Test Login Flow

Fill and Submit Form

Check for Broken Links

Take Screenshot with Error Handling

Test Responsive Design

Inline Execution (Simple Tasks)

Available Helpers

Custom HTTP Headers

Configuration

How It Works

Advanced Usage

Tips

Troubleshooting

Example Usage

Notes

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