Browser Drivers

QUESTPIE Probe uses an adapter pattern for browser automation. Both drivers are installed automatically as peer dependencies.

agent-browser (Default)

agent-browser by Vercel Labs is a Rust-based CLI that runs a persistent browser daemon. Default driver, optimized for AI coding agents.

• Persistent daemon — browser stays open between CLI calls
• Session-based — cookies and localStorage persist across commands
• Accessibility snapshots — structured a11y trees instead of raw HTML (token-efficient)
• Ref-based targeting — elements identified by @ref numbers from snapshots

qprobe browser open http://localhost:3000
qprobe browser snapshot          # Returns a11y tree with @ref numbers
qprobe browser click @14         # Click element with ref 14
qprobe browser fill @7 "hello"   # Fill input at ref 7

Playwright

Playwright by Microsoft provides cross-browser automation and test execution. Used by qprobe replay to run recorded tests.

• Cross-browser — Chromium, Firefox, WebKit
• CSS selector targeting — standard selectors instead of refs
• Powers qprobe replay test execution
• Install browsers after first install: bunx playwright install

Configuration

Set the driver in qprobe.config.ts:

import { defineConfig } from '@questpie/probe'

export default defineConfig({
  browser: {
    driver: 'agent-browser', // 'agent-browser' | 'playwright'
    baseUrl: 'http://localhost:3000',
    headless: true,
    session: 'qprobe',
  },
})

Or via environment variable:

QPROBE_BROWSER_DRIVER=playwright qprobe browser open http://localhost:3000

Comparison