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Phase 14

Playwright

~3 min read

Concept & How It Works

    Why Does It Exist?

    Agents that interact with the web need programmatic control over navigation, clicks, form fills, and screenshots. Playwright is faster and more reliable than Selenium, with auto-waiting, network interception, and headless/headed modes.

    Real-World Analogy

    Playwright is a remote control for a web browser — your agent presses buttons, reads screens, and navigates pages as if a human were sitting at the computer.
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    Visual Workflows

    What is Playwright?

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    Example

    Scenario

    Agent navigates to a SaaS dashboard, logs in with stored credentials, clicks 'Export CSV', waits for download, and parses the file for analysis.

    Solution

    In Browser & Computer Use Agents, apply Playwright to this scenario: Agent navigates to a SaaS dashboard, logs in with stored credentials, clicks 'Export CSV', waits for download, and parses the file for analysis. Identify the inputs, run the technique, validate the output, and note one thing you would monitor in production.

    Practice Task

    Do this before moving to the next module — reading alone is not enough.

    Open the Code Walkthrough below and run it locally. Change one parameter related to Playwright (e.g. model, temperature, top_k, or tool name), observe the difference in output, and write 2–3 sentences explaining what changed.

    Code Walkthrough

    Highlighted lines show where Playwright happens in the code.

    Playwright
    1from playwright.async_api import async_playwright  # import dependencies2
    3async def scrape_pricing(url: str) -> str:4    async with async_playwright() as p:  # key line for Playwright5        browser = await p.chromium.launch(headless=True)6        page = await browser.new_page()7        await page.goto(url)8        await page.wait_for_selector("[data-testid='price']")9        price = await page.locator("[data-testid='price']").text_content()10        await browser.close()11        return price  # return the result

    Commands to Remember

    Commands to Remember

    • pip install playwright # browser automation
    • playwright install # install browser binaries

    Common Mistakes

    • Treating Playwright as a black box without evaluation
    • Ignoring cost and latency in production
    • Skipping error handling for playwright

    Cheat Sheet

    Quick recap — the most important points from this module.

    Cheat Sheet

    quick ref
    • Playwright
    • Headless Browser
    • Locator
    • Auto-wait