Rune

The simplest agent harness for Claude Code
One file per agent. Run headlessly, chain them together, automate with triggers, or chat in the desktop UI.

Why Rune?

Building a Claude Code harness usually means wiring up process management, I/O parsing, state handling, and a UI from scratch.

Rune replaces all of that with a single file.

npm install -g openrune

rune new reviewer --role "Code reviewer, security focused"
rune run reviewer.rune "Review the latest commit"

That's it. No SDK, no boilerplate, no config.

Quick Start

Prerequisites

• Node.js 18+
• Claude Code CLI — npm install -g @anthropic-ai/claude-code

Install

npm install -g openrune

Create and run agents

# Create agents
rune new architect --role "Software architect"
rune new coder --role "Backend developer"
rune new reviewer --role "Code reviewer"

# Run headlessly
rune run reviewer.rune "Review the latest commit"

# Pipe input
git diff | rune run reviewer.rune "Review this diff"

# Agent pipeline — architect designs, coder builds (with file creation)
rune pipe architect.rune coder.rune "Build a REST API with Express" --auto

# Open desktop UI
rune open reviewer.rune

How It Works

Each .rune file is an independent AI agent:

{
  "name": "reviewer",
  "role": "Code reviewer, security focused",
  "history": [],
  "memory": []
}

• Portable — It's just JSON. Commit to git, share with teammates, move between machines.
• Persistent — Role, memory, and chat history live in the file. The agent picks up where it left off.
• Independent — Multiple agents in the same folder, each with their own context.

Agent Pipeline

Chain agents together. Each agent's output feeds into the next:

rune pipe architect.rune coder.rune reviewer.rune "Add OAuth2 login flow"

architect designs → coder implements → reviewer checks.

With --auto, the last agent can write files and run commands:

rune pipe architect.rune coder.rune "Build a REST API with Express" --auto

Autonomous Mode

--auto lets agents write files, run commands, and fix errors on their own:

rune run coder.rune "Create a server.js with Express, run npm init and npm install" --auto

You see every action in real-time:

🔮 [auto] coder is working on: Create a server.js...

  ▶ Write: /path/to/server.js
  ▶ Bash: npm init -y
  ▶ Bash: npm install express
  💬 Server created and dependencies installed.

✓ coder finished

Automated Triggers

Run agents automatically on events:

# On every git commit
rune watch reviewer.rune --on git-commit --prompt "Review this commit"

# On file changes
rune watch linter.rune --on file-change --glob "src/**/*.ts" --prompt "Check for issues"

# On a schedule
rune watch monitor.rune --on cron --interval 5m --prompt "Check server health"

Node.js API

Use agents in your own code:

const rune = require('openrune')

// Single agent
const reviewer = rune.load('reviewer.rune')
const result = await reviewer.send('Review the latest commit')

// Pipeline
const { finalOutput } = await rune.pipe(
  ['architect.rune', 'coder.rune'],
  'Build a REST API'
)

Works in Express servers, scripts, CI/CD — anywhere Node.js runs.

Desktop UI

Double-click a .rune file or run rune open for an interactive chat interface.

• Real-time activity — See every tool call, result, and permission request via Claude Code hooks.
• Built-in terminal — Claude Code output and your own commands, side by side.
• Right-click to create — macOS Quick Action for creating agents from Finder.

Use Cases

CLI Reference

Watch events: git-commit, git-push, file-change (with --glob), cron (with --interval)

Architecture

  Harness Mode (rune run / pipe / watch):
    CLI → Claude Code (-p) → stdout
    No GUI, no MCP — direct execution with .rune context

  Desktop UI Mode (rune open / double-click):
    Chat UI (React) ↔ Electron ↔ MCP Channel ↔ Claude Code CLI
    Real-time hooks for activity monitoring

Development

git clone https://github.com/gilhyun/Rune.git
cd Rune
npm install
npm start

Project Structure

bin/rune.js              CLI (new, run, pipe, watch, open, list)
lib/index.js             Node.js API
channel/rune-channel.ts  MCP channel + hooks endpoint
src/main.ts              Electron main process
renderer/src/            React chat UI + terminal

Platform Support

License

MIT