stagehand

```javascript
const { chromium } = require('playwright');

(async () => {
  const browser = await chromium.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com/login');

  // Fill in the username and password
  await page.fill('#username', 'john_doe');
  await page.fill('#password', 'securePassword123');

  // Click the login button
  await page.click('#loginButton');

  // Wait for navigation
  await page.waitForNavigation();

  // Check if login was successful
  const loggedIn = await page.isVisible('#welcomeMessage');
  console.log(loggedIn ? 'Login successful!' : 'Login failed.');

  await browser.close();
})();
```