playwright-skill

description	Playwright primitives for real-browser automation — dev-server detection, a Node.js script runner, and helpers for clicks, form fills, screenshots, multi-viewport, custom HTTP headers. Use when a task needs an actual browser (rendered DOM, visual checks, multi-page flows, cross-browser behavior). Not for API tests or logic tests where curl or JSDOM is cheaper.
name	playwright-skill

Playwright Browser Automation

Provides primitives for browser automation: dev-server detection, a script runner (scripts/run.js), and helper utilities (scripts/lib/helpers.js).

Critical workflow

1. Detect dev servers first for localhost testing:

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

   One server → use it. Multiple → ask which. None → ask for a URL.

2. Write generated scripts to /tmp/playwright-test-*.js — never into scripts/ or the user's project.

3. Visible browser by default (headless: false). Headless only when the user asks.

4. Parameterize the target URL at the top of the script as TARGET_URL.

Running scripts

node scripts/run.js /tmp/playwright-test-<name>.js   # file
node scripts/run.js "<code>"                          # inline
cat script.js | node scripts/run.js                   # stdin

run.js cds to its own directory for module resolution, auto-wraps non-async code, and on first run auto-installs Playwright via bun. For code without require() it injects globals: chromium, firefox, webkit, devices, helpers, and getContextOptionsWithHeaders(opts).

Helpers

scripts/lib/helpers.js exports: launchBrowser, createPage, createContext, waitForPageReady, safeClick, safeType, extractTexts, extractTableData, takeScreenshot, authenticate, scrollPage, handleCookieBanner, retryWithBackoff, detectDevServers, getExtraHeadersFromEnv.

Open the file when you need a signature.

Custom HTTP headers

Set env vars before invoking run.js to inject extra headers into every request:

# single header
PW_HEADER_NAME=X-Automated-By PW_HEADER_VALUE=playwright-skill \
  node scripts/run.js /tmp/script.js

# multiple
PW_EXTRA_HEADERS='{"X-Automated-By":"playwright-skill","X-Debug":"true"}' \
  node scripts/run.js /tmp/script.js

Headers apply automatically when scripts use helpers.createContext(browser). For raw browser.newContext(...), wrap options with getContextOptionsWithHeaders(...).

Failure handling

• run.js not found: check that playwright-skill dir is on the skill path; run from that directory explicitly.
• Dev server not detected: ask the user for the URL rather than assuming localhost:3000.
• Script syntax error: quote the failing line, state the cause, rewrite the offending section — do not re-run the broken script.
• Playwright not installed: run.js auto-installs on first run; if that fails, run cd <skill-dir> && bun install or npm install.

References

• references/setup.md — first-time install (bun preferred, npm fallback).
• references/api.md — selectors, locators, network interception, auth, visual regression, mobile emulation, performance, debugging, CI/CD.