Harness Kit
Getting Started

Installation

Three ways to install harness-kit — pick what fits your workflow.

Using a coding agent? Install the Harness Kit docs as a skill:
npx skills add https://github.com/harnessprotocol/harness-kit --skill harness-docs

Desktop App

The full harness-kit experience. Observatory, Memory, Board, and a Cmd+K command palette — all in one native app with a visual interface for managing your AI tool configurations.

Tap the Harness Kit Homebrew cask

brew tap harnessprotocol/tap
brew install --cask harness-kit

Clear the quarantine flag

The app is not yet notarized. Run this before first launch:

xattr -cr "/Applications/Harness Kit.app"

Or right-click the app in Finder → Open → confirm.

Launch from Applications or Spotlight

Search Harness Kit or open from /Applications/Harness Kit.app.

Download the DMG

Download the .dmg for your architecture from GitHub Releases.

Drag to Applications

Open the .dmg and drag Harness Kit to your Applications folder.

Clear the quarantine flag

xattr -cr "/Applications/Harness Kit.app"

Launch from Applications or Spotlight

Install the nightly build

Rebuilt daily from main. Use this to get the latest features before a stable release.

brew tap harnessprotocol/tap
brew install --cask harnessprotocol/tap/'harness-kit@nightly'

Clear the quarantine flag

xattr -cr "/Applications/Harness Kit.app"

Launch from Applications or Spotlight

Search Harness Kit or open from /Applications/Harness Kit.app.

To switch back to stable

brew uninstall --cask harnessprotocol/tap/'harness-kit@nightly'
brew install --cask harnessprotocol/tap/harness-kit

Nightly builds may be unstable

These are unversioned builds from the tip of main. Rebuilt every day at midnight UTC. Data formats and APIs may change without notice.

System requirements

macOS 14 (Sonoma) or later, Apple Silicon (arm64). Intel builds are planned.


Skills & Plugins

Slash commands for Claude Code. Add the marketplace once, install any plugin by name.

Add the marketplace

/plugin marketplace add harnessprotocol/harness-kit

Install plugins by name

/plugin install research@harness-kit
/plugin install explain@harness-kit
/plugin install orient@harness-kit

No plugin marketplace access? Use the install script:

curl -fsSL https://raw.githubusercontent.com/harnessprotocol/harness-kit/main/install.sh | bash

This copies skill files to ~/.claude/skills/ over HTTPS. Bundled scripts (like the research index rebuilder) require the full marketplace install.

Verify: invoke any skill after installing:

/research
/explain src/main.ts

Using with other tools

SKILL.md files are plain markdown — copy them into any tool's instruction system. See Using with Other Tools for Copilot, Cursor, and Windsurf setup.


CLI

Compile harness.yaml, sync plugins, detect drift — from the terminal.

brew tap harnessprotocol/tap
brew install harness-kit
npm install -g @harness-kit/cli

Requires Node.js 22 or later.

Download the standalone binary (no Node.js required) from GitHub Releases:

tar -xzf harness-darwin-arm64.tar.gz
chmod +x harness
sudo mv harness /usr/local/bin/
brew tap harnessprotocol/tap
brew install harnessprotocol/tap/harness-kit-nightly

Latest build from main. Rebuilt daily at midnight UTC. Installs as harness-kit-nightly — no conflict with the stable harness-kit binary.

Verify:

harness --version
harness validate

Plugin Requirements

Environment variables

Some plugins use optional env vars. See Secrets Management for how to configure them.

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