On this page
What Haarness is
Haarness is a coding agent. You open it in a project folder and ask for something in plain words. It reads your code, edits files, runs commands such as your tests, and tells you what it did. You review the change, then keep it or undo it.
It runs on your machine and works with the model you already pay for: an API key, a ChatGPT, GitHub Copilot or SuperGrok subscription, a model running on your computer, or Haarness Cloud. You do not need an account.
Get started
Four short pages take you from nothing to a change you have reviewed:
- Install Haarness: one command for the terminal app and Desktop.
- Connect a provider: sign in or paste a key.
- Your first chat: ask a question, make a change, review it, undo it.
- Learn the app you will use every day: the terminal UI or Desktop.
Ways to use it
| You want to | Use |
|---|---|
| Work in the terminal | haarness, the terminal UI |
| Work in an app window | Haarness Desktop |
| Run a prompt from a script or CI | haarness run |
| Use it from your editor | haarness acp |
| Keep it working while your laptop is closed | Haarness Cloud |
The terminal UI and Desktop share the same chats for a project folder. Closing either one does not stop work that is already running.
Before you let it loose
- Inside your project it acts without asking. Haarness edits files and runs commands in the
project folder without a prompt. It asks first before it works outside the folder, reads a
secret such as a
.envfile, or does a few other sensitive things. That is Review, the mode every chat starts in. Auto hands those questions to a reviewer model instead. You can also make it ask before every edit or command: see Permissions. - Permissions are not a sandbox. They catch an agent doing something you did not intend. They do not contain code that is trying to escape. Read Trust boundaries before you run it on code you do not trust.
- Your code and chats stay on your machine. Haarness sends model requests to the provider you connect, and nowhere else.
- It shares a daily summary of usage counts with Haarness Cloud, unless you turn that off. The
summary counts chats, turns, tokens and tool calls, and names the built-in models and tools you
used. It never contains prompts, answers, code, file names or paths. Turn it off with
haarness telemetry off,/usage-statisticsin the terminal UI, or Settings → General → Share usage statistics in Desktop. Usage statistics lists every field.
Apart from that summary, Haarness contacts Haarness Cloud only when you ask it to: to sign in, use a Cloud model or browse the marketplace, for example.
Is it open source?
Yes. The agent, the terminal app, Desktop, the server and the SDKs are open source under the Apache 2.0 license, and the router is MIT. Haarness Cloud is the optional hosted service built on the same code. See Open source.
Do I need Haarness Cloud?
No. Everything above works on your own machine for free. Haarness Cloud adds models without provider keys, Cloud workspaces that keep running on a hosted machine, and one account for the CLI, Desktop and the web. Local or Cloud helps you choose.