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Govern Browser Automation with Playwright in 5 Minutes

Browser agents can navigate pages, fill forms, click buttons, and execute JavaScript. Aegis ensures they stay within policy.

What you will build: Browser governance where navigation is free, form fills need approval, and JavaScript execution is blocked.

Time: 5 minutes.

Prerequisites

pip install 'agent-aegis[playwright]'
playwright install chromium

Step 1: Write Your Policy

# policy.yaml
version: "1"
defaults:
  risk_level: medium
  approval: approve

rules:
  - name: navigate_auto
    match: { type: "navigate" }
    risk_level: low
    approval: auto

  - name: screenshot_auto
    match: { type: "screenshot" }
    risk_level: low
    approval: auto

  - name: click_approve
    match: { type: "click" }
    risk_level: medium
    approval: approve

  - name: fill_approve
    match: { type: "fill" }
    risk_level: medium
    approval: approve

  - name: submit_high
    match: { type: "submit" }
    risk_level: high
    approval: approve

  - name: eval_block
    match: { type: "eval" }
    risk_level: critical
    approval: block

Step 2: Use the Playwright Executor

import asyncio
from aegis import Action, Policy, Runtime
from aegis.adapters.playwright import PlaywrightExecutor

async def main():
    executor = PlaywrightExecutor(headless=True)
    policy = Policy.from_yaml("policy.yaml")

    async with Runtime(executor=executor, policy=policy) as runtime:
        # Navigate: auto-approved
        result = await runtime.run_one(
            Action("navigate", "browser", params={"url": "https://example.com"})
        )
        print(f"Navigate: {result.status}")

        # Screenshot: auto-approved
        result = await runtime.run_one(
            Action("screenshot", "browser", params={"path": "page.png"})
        )
        print(f"Screenshot: {result.status}")

        # Click: needs approval
        result = await runtime.run_one(
            Action("click", "browser", params={"selector": "a"})
        )
        print(f"Click: {result.status}")

asyncio.run(main())

Browser Action Types

Action Risk Use Case
navigate Low Open a URL
screenshot Low Capture page state
scroll Low Scroll page
click Medium Click buttons, links
fill Medium Enter data in forms
submit High Submit forms (irreversible)
upload High Upload files
download Medium Download files
eval Critical Execute arbitrary JavaScript

Next Steps