Browser Automation Skill Skill

Browser Automation Skill

Setup

pip install playwright && playwright install chromium
pip install playwright-stealth  # optional, for anti-detection

Skill Comparison

| Skill | Use Case | | -------------------- | ---------------------------------------------- | | browser-automation | Scripted automation, data pipelines, form bots | | webapp-testing | QA assertions, visual regression, test suites | | chrome-browser | Interactive MCP DevTools control |

Iron Law

NEVER USE time.sleep() — use page.wait_for_selector() or wait_for_load_state()

Core Patterns

Navigation and Extraction

with sync_playwright() as p:
    context = p.chromium.launch(headless=True).new_context(
        user_agent="Mozilla/5.0 ...", viewport={"width": 1280, "height": 720})
    page = context.new_page()
    page.goto(url); page.wait_for_load_state("networkidle")
    items = [i.inner_text() for i in page.get_by_role("listitem").all()]

Form Filling

page.get_by_label("Email").fill("user@example.com")
page.get_by_label("Password").fill("secret")
with page.expect_navigation():
    page.get_by_role("button", name="Submit").click()

Screenshot and PDF

page.screenshot(path="full.png", full_page=True)
page.pdf(path="page.pdf", format="A4", print_background=True)

Auth Session Management

# Save session
context.storage_state(path="auth-state.json")
# Reuse session
context = browser.new_context(storage_state="auth-state.json")

Anti-Detection

browser = p.chromium.launch(args=["--disable-blink-features=AutomationControlled"])
context = browser.new_context(user_agent="...", locale="en-US", timezone_id="America/New_York")
page.add_init_script("Object.defineProperty(navigator, 'webdriver', {get: () => undefined})")

Agent Usage

Save extracted data to .claude/context/tmp/ as structured JSON
Save screenshots/PDFs to .claude/context/artifacts/
Never commit auth-state.json — add to .gitignore

Anti-Patterns

| Anti-Pattern | Correct Approach | | ------------------------ | ---------------------------------------------------- | | time.sleep() for waits | page.wait_for_selector() / wait_for_load_state() | | CSS selectors for forms | get_by_label(), get_by_role() | | Re-login each run | context.storage_state() persistence | | Committing auth state | Add auth-state.json to .gitignore |

Memory Protocol (MANDATORY)

Before starting: Read .claude/context/memory/learnings.md

After completing:

New extraction pattern -> .claude/context/memory/learnings.md
Bot detection encountered -> .claude/context/memory/issues.md

ASSUME INTERRUPTION: If it's not in memory, it didn't happen.

Agent Skills: Browser Automation Skill

Install this agent skill to your local

Skill Files