🧰 What is harness-kit?

Your AI coding setup — plugins, skills, MCP servers, hooks, conventions — packaged into a single config you can apply to any tool on any machine. Build it once, share it with your team in one file.

📦 Install

Skills & Plugins (Claude Code):

/plugin marketplace add harnessprotocol/harness-kit

CLI (harness validate, compile, sync, ...):

brew tap harnessprotocol/tap && brew install harness-kit
# or: npm install -g @harness-kit/cli  # requires Node.js 22+

Desktop App:

brew tap harnessprotocol/tap  # skip if you already ran this above
brew install --cask harness-kit

Or download the .dmg directly from the latest release and drag Harness Kit.app to /Applications. Note: the app is not notarized — right-click and select Open on first launch.

brew tap harnessprotocol/tap  # skip if already added
brew install harnessprotocol/tap/harness-kit-nightly          # CLI nightly → installs as harness-kit-nightly
brew install --cask harnessprotocol/tap/'harness-kit@nightly' # desktop nightly

Nightly builds track the tip of main and are rebuilt every day at midnight UTC. Use them to get the latest features before a stable release — at the cost of stability guarantees.

If your Claude Code build doesn't support the plugin marketplace:

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

Downloads skill files to ~/.claude/skills/ over HTTPS. The full plugin experience (scripts, hooks, agents) requires the marketplace install.

⚡ Quick Start

Install explain — no dependencies, works in any codebase:

/plugin install explain@harness-kit

Then try it:

/explain src/auth/middleware.ts       # explain a specific file
/explain the payment processing flow  # search the codebase for a concept
/explain src/services/                # map a directory

Produces a layered explanation: summary, key components, how it connects, patterns, gotchas, and where to start if you need to change it.

🔌 Plugins

A few highlights to get started:

📋 Browse all 16 plugins → or run /plugin marketplace browse harness-kit

🌍 Community

/plugin marketplace add obra/superpowers-marketplace
/plugin install superpowers@obra

🔄 Share Your Setup

Export your plugin setup to a harness.yaml, commit it to your dotfiles, and restore it anywhere.

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

See harness.yaml.example for the config format. harness.yaml follows the Harness Protocol v1 open spec — a vendor-neutral format for portable AI coding harnesses.

🔒 Security & Privacy

• No telemetry, no data collection — harness-kit never phones home. Optional stats are local-only.
• Secrets stay out of config — plugins declare environment variables they need (requires.env in plugin.json) with required, optional, and sensitive flags. Values live in your shell profile, direnv, or a secrets manager — never in checked-in files. The framework validates existence but never reads or logs values.
• Plain text, fully inspectable — plugins are markdown and JSON. No binaries, no background processes, no network calls on install. Scripts and hooks only run when you explicitly invoke a skill.
• Granular permissions — tool-level allow/deny/ask, path-level write restrictions, and network host allowlists. All configurable per-project.
• Audit logging — permission changes, secret access, and preset applications are logged with timestamps.
• Prompt injection detection — the research plugin treats all external content as untrusted, scanning for injection attempts before processing.

See the Secrets Management guide for setup with 1Password, direnv, Google Secret Manager, and CI environments.

🖥️ Desktop App

A Tauri desktop companion that brings the harness concept to a native UI.

• Sync engine — compiles harness.yaml to platform configs
• Plugin explorer — browse and manage installed plugins
• Marketplace — embedded plugin browser for discovering and installing from the marketplace
• Observatory — live session dashboard with stats and transcripts
• Comparator — structured evaluation workbench: configure harnesses, run side-by-side comparisons, review file diffs, and judge results across a 4-phase workflow
• Harness editor — inline editing with custom profiles
• Board — kanban project board with real-time Claude-to-web sync; per-card agent execution via LangGraph with live phase/progress streaming, subtask tracking, steering, pause/resume, and tool-level permission controls
• Roadmap — AI-driven product roadmap with competitor analysis, generated via Claude
• Parity — cross-platform feature parity tracking across AI coding tools
• Security — permissions editor, secrets management, and audit logging
• Memory — membrain MCP server: graph-based agent memory with 11 graph tools, semantic dedup, and token-savings telemetry
• Team chat — IRC-style chat backed by a self-hosted WebSocket relay
• AI Chat — streaming conversations with local LLMs via Ollama, with session persistence and inline model downloads

See apps/desktop/ for build instructions. The desktop app is a separate product from the plugin marketplace.

🌐 Cross-Platform

• Claude Code — native plugin marketplace support
• Cursor — SKILL.md files work as prompt instructions; /harness-compile generates native config
• GitHub Copilot — reads CLAUDE.md natively via chat.useClaudeMdFile

See the Harness Protocol spec for the full cross-platform target mapping.

📚 Docs

• FAQ — What is this, why do I need it, how does it work
• Plugins vs. Skills — Why everything ships as a plugin, even when it's just a prompt
• Claude Conventions — Organizing CLAUDE.md, AGENT.md, and SOUL.md with separation of concerns
• Understanding Agents — AGENT.md, custom subagents, and "AI agent" disambiguation

🤝 Contributing

See CONTRIBUTING.md for plugin guidelines, skill conventions, and PR process.

📬 Contact

• General — [email protected]
• Security — [email protected] (see SECURITY.md)

📄 License

Apache 2.0