<img src="https://r2.browser-use.com/github/ajsdlasnnalsgasld.png" alt="Browser Harness" width="100%" />

# Browser Harness ♞

The simplest, thinnest, **self-healing** harness that gives LLM **complete freedom** to complete any browser task. Built directly on CDP.

The agent writes what's missing, mid-task. No framework, no recipes, no rails. One websocket to Chrome, nothing between.

```
  ● agent: wants to upload a file
  │
  ● helpers.py → upload_file() missing
  │
  ● agent edits the harness and writes it    helpers.py   192 → 199 lines
  │                                                       + upload_file()
  ✓ file uploaded
```

**You will never use the browser again.**

## Setup prompt

Paste into Claude Code or Codex:

```text
Set up https://github.com/browser-use/browser-harness for me.

Read `install.md` first to install and connect this repo to my real browser. Then read `SKILL.md` for normal usage. Always read `helpers.py` because that is where the functions are. When you open a setup or verification tab, activate it so I can see the active browser tab. After it is installed, if I am already logged in to GitHub, star this repository as a small verification task; if I am not logged in, just go to browser-use.com.
```

When this page appears, tick the checkbox so the agent can connect to your browser:

<img src="docs/setup-remote-debugging.png" alt="Remote debugging setup" width="520" style="border-radius: 12px;" />

Example task: `Star this repository` · see [domain-skills/](domain-skills/) for more

## Remote browsers

Useful for sub-agents or deployment. **Free tier: 3 concurrent browsers, no card required.**

- Grab a key at [cloud.browser-use.com/new-api-key](https://cloud.browser-use.com/new-api-key)
- Or let the agent sign up itself via [docs.browser-use.com/llms.txt](https://docs.browser-use.com/llms.txt) (setup flow + challenge context included).

## How simple is it? (~592 lines of Python)

- `install.md` — first-time install and browser bootstrap
- `SKILL.md` — day-to-day usage
- `run.py` (~36 lines) — runs plain Python with helpers preloaded
- `helpers.py` (~195 lines) — starting tool calls; the agent edits these
- `admin.py` + `daemon.py` (~361 lines) — daemon bootstrap plus the CDP websocket and socket bridge

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[Bitter lesson](https://browser-use.com/posts/bitter-lesson-agent-frameworks) · [Skills](https://browser-use.com/posts/web-agents-that-actually-learn)