Playwright Browser Automation
Executes end-to-end browser automation with robust Playwright patterns and helpers.
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:
terminalLoading...- 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: falseunless 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)
This installs Playwright and Chromium browser. Only needed once.
Execution Pattern
Step 1: Detect dev servers (for localhost testing)
Step 2: Write test script to /tmp with URL parameter
Step 3: Execute from skill directory
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)
For quick one-off tasks, you can execute code inline without creating files:
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:
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):
Multiple headers (JSON format):
How It Works
Headers are automatically applied when using helpers.createContext():
For scripts using raw Playwright API, use the injected getContextOptionsWithHeaders():
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_VALUEenv 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_URLconstant at the top of every script - DEFAULT: Visible browser - Always use
headless: falseunless user explicitly asks for headless mode - Headless mode - Only use
headless: truewhen user specifically requests "headless" or "background" execution - Slow down: Use
slowMo: 100to make actions visible and easier to follow - Wait strategies: Use
waitForURL,waitForSelector,waitForLoadStateinstead 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:
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
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
/tmpfor 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