# Browser Harness — Self-Healing Browser Automation for LLMs

> A persistent browser harness by Browser Use that enables LLMs to complete any web task with self-healing navigation and automatic error recovery.

## Install

Save in your project root:

# Browser Harness — Self-Healing Browser Automation for LLMs

## Quick Use
```bash
pip install browser-harness
browser-harness start --port 9222
# Connect your agent via CDP endpoint
```

## Introduction
Browser Harness is a persistent, self-healing browser runtime built for AI agents. It extends the Browser Use ecosystem with cloud-ready browser instances that LLMs can control to complete complex web tasks, automatically recovering from navigation errors and page changes.

## What Browser Harness Does
- Provides persistent browser sessions accessible via Chrome DevTools Protocol
- Implements self-healing navigation that adapts to page layout changes
- Supports multi-tab workflows with isolated session contexts
- Handles authentication persistence across agent sessions
- Offers cloud and VPS deployment modes for remote browser access

## Architecture Overview
Browser Harness runs a managed Chromium instance exposed via CDP. A middleware layer intercepts agent commands and applies self-healing logic: if a selector fails, it attempts fuzzy matching, visual element detection, and DOM re-analysis before retrying. Sessions persist across agent reconnections with full cookie and storage state preservation.

## Self-Hosting & Configuration
- Deploy via Docker with a single container image
- Configure CDP port and authentication via environment variables
- Set up persistent storage volumes for session state
- Scale horizontally with multiple browser instances behind a load balancer
- Integrate with Telegram or Slack for remote agent monitoring

## Key Features
- Self-healing selectors that adapt to DOM changes automatically
- Persistent sessions surviving agent disconnects and reconnects
- Cloud-native deployment with Docker and Kubernetes support
- Built-in screenshot and video recording for debugging
- CDP-compatible interface working with Playwright and Puppeteer

## Comparison with Similar Tools
- **Browser Use** — the Python agent library; Browser Harness is the persistent runtime
- **Playwright** — browser automation library; Browser Harness adds self-healing and persistence
- **Stagehand** — AI browser framework; Browser Harness focuses on infrastructure
- **Selenium** — traditional automation; Browser Harness is designed for LLM agent workflows

## FAQ
**Q: How does self-healing work?**
A: When a CSS selector fails, the harness uses fuzzy matching, ARIA attributes, and visual analysis to locate the intended element and retry the action.

**Q: Can multiple agents share one browser instance?**
A: Yes. The harness supports isolated tab contexts so multiple agents can operate concurrently in separate tabs.

**Q: What browsers are supported?**
A: Chromium-based browsers via the Chrome DevTools Protocol.

**Q: How do I persist login sessions?**
A: Session storage and cookies are saved to disk by default and restored on reconnect.

## Sources
- https://github.com/browser-use/browser-harness


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Source: https://tokrepo.com/en/workflows/asset-b12b2c76
Author: AI Open Source