# Browser Harness — Self-Healing Browser Automation for LLM Agents

> A self-healing browser harness by the Browser Use team that enables LLMs to complete any web task with persistent sessions, CDP integration, and automatic recovery from failures.

## Install

Save as a script file and run:

# Browser Harness — Self-Healing Browser Automation for LLM Agents

## Quick Use
```bash
pip install browser-harness
python -m browser_harness --help
```

## Introduction
Browser Harness is a self-healing automation framework from the Browser Use team. It enables LLM agents to interact with web pages, fill forms, navigate sites, and complete multi-step tasks in a real browser. When elements move or pages change, the harness automatically adapts its selectors and retries, making agent-driven web workflows robust in production.

## What Browser Harness Does
- Provides LLM agents with a persistent browser session via Chrome DevTools Protocol (CDP)
- Automatically recovers from selector failures by re-identifying page elements using AI
- Supports multi-tab and multi-window workflows within a single agent session
- Integrates with Playwright for reliable cross-browser rendering and interaction
- Exposes a Python API for embedding browser actions into agent tool pipelines

## Architecture Overview
Browser Harness wraps a Playwright-managed Chromium instance and exposes browser actions as callable tools for LLM agents. It maintains a persistent session state including cookies, local storage, and open tabs. When an action fails due to a changed DOM, the self-healing module captures a screenshot, sends it to the LLM for element re-identification, and retries the action with updated selectors. Communication between the agent and the browser happens over CDP, keeping latency low.

## Self-Hosting & Configuration
- Install from PyPI with pip install browser-harness
- Requires a local Chromium or Chrome installation (or use the bundled Playwright browsers)
- Configure the LLM provider (OpenAI, Anthropic, or compatible) via environment variables
- Set headless or headed mode, viewport size, and timeout defaults in the config file
- Deploy in Docker for CI/CD pipelines with the included Dockerfile

## Key Features
- Self-healing selectors automatically adapt when page layouts change
- Persistent browser sessions maintain login state across multiple agent turns
- Screenshot-based fallback lets the LLM visually identify elements when DOM queries fail
- Cloud browser support for running sessions on remote VPS or container infrastructure
- Open-source with active development and community contributions

## Comparison with Similar Tools
- **Browser Use** — the original agent browser library; Browser Harness extends it with self-healing and persistence
- **Playwright** — powerful browser automation but requires manual selector maintenance; Browser Harness adds AI-driven recovery
- **Selenium** — traditional browser testing framework; Browser Harness is purpose-built for LLM agent workflows
- **Stagehand** — AI browser automation with a different API design; Browser Harness focuses on session persistence
- **Pydoll** — WebDriver-free automation; Browser Harness uses CDP with self-healing on top

## FAQ
**Q: Does Browser Harness work with any LLM provider?**
A: Yes, it supports OpenAI, Anthropic, and any OpenAI-compatible API for the self-healing element identification.

**Q: Can I run Browser Harness in headless mode?**
A: Yes, headless mode is the default for server and CI environments. Switch to headed mode for debugging.

**Q: How does the self-healing work?**
A: When a selector fails, the harness captures a screenshot, sends it to the configured LLM, and asks it to identify the target element. It then generates a new selector and retries the action.

**Q: Is there a Docker image available?**
A: Yes, the repository includes a Dockerfile for containerized deployment with pre-installed browser dependencies.

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


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Source: https://tokrepo.com/en/workflows/asset-17b4a50f
Author: Script Depot