Harn icon

Harn

AI coding assistant for the terminal and the desktop.

Native Mac AI-coding environment with on-device inference and model training - a multi-provider coding CLI in Rust, a native desktop app, and a bundled local engine for Apple Silicon.

Inside the Manage app

One native window to install, inspect, and manage every part of Harn.

Overview tab of the Harn Manage app

Overview

A grounded health snapshot: version, backend, served model, all probed from disk.

Components tab of the Harn Manage app

Components

Everything Harn put on disk, sized and removable. Tick items and Remove, never a mass-uninstall.

Install tab of the Harn Manage app

Install

The app, CLI, and local engine in one click. Everything is bundled, no build tools needed.

Model tab of the Harn Manage app

Model

Search HuggingFace, download and activate a local MLX model, or drag your own in.

Crucible tab of the Harn Manage app

Crucible

Point the on-device training store at any drive. Only the link moves, weights never do.

Services tab of the Harn Manage app

Services

Start, stop, or restart the local inference engine and open its log.

Databases tab of the Harn Manage app

Databases

Install the AI knowledge base: models, inference notes, technique references.

Guide tab of the Harn Manage app

Guide

Every tab explained in the window, so nothing needs a manual.

Features

Multi-provider: local models or cloud APIs

Terminal CLI and native desktop app

On-device inference on Apple Silicon

On-device model training (crucible)

One-click installer and doctor

First launch

Downloads are zipped Mac apps. They are not notarized by Apple yet: after unzipping, open System Settings → Privacy & Security and click "Open Anyway" the first time. Protected builds include a 14-day free trial. After purchase on Gumroad, you receive a one-line T1.… license key. GUI apps show an activation dialog on first launch. Paste your key and click Activate. CLI tools accept the key via TOWEL_OBF_LICENSE environment variable.

If Gatekeeper blocks the unzipped app, drop it on Towel Signer.

Support

Problem with Harn? Email toweltoolshop@gmail.com.