Open Claude Code

Open Source Claude Code CLI — Reverse Engineered & Rebuilt

⚡ Quick Start

# Run instantly (no install)
npx @ruvnet/open-claude-code "explain this codebase"
# Or install globally
npm install -g @ruvnet/open-claude-code
occ "hello"
# Interactive mode
occ

export ANTHROPIC_API_KEY=sk-ant-...
npx @ruvnet/open-claude-code "what files are in this directory?"

🧠 What Is This?

📦 Installation

npx (no install needed)

npx @ruvnet/open-claude-code "your prompt here"

Global install

npm install -g @ruvnet/open-claude-code
occ "your prompt here"

From source

git clone https://github.com/ruvnet/open-claude-code.git
cd open-claude-code/v2
export ANTHROPIC_API_KEY=sk-ant-...
node src/index.mjs "hello"

🖥️ Usage

One-shot mode

occ "explain the auth module"
occ "fix the bug in server.js"
occ "create a REST API for user management"
occ "find all TODO comments in this project"

Interactive REPL

occ
# > explain this codebase
# > /help
# > /tools
# > /model claude-opus-4-6
# > refactor the database layer
# > /cost
# > /exit

CLI Options

occ [options] [prompt]
Options:
 -m, --model <model> Model to use (default: claude-sonnet-4-6)
 -p, --print Print mode (non-interactive, output only)
 --permission-mode <mode> Permission mode: default, auto, plan, acceptEdits, 
 bypassPermissions, dontAsk
 --system-prompt <text> Override system prompt
 --add-dir <path> Additional CLAUDE.md directory
 --max-turns <n> Maximum conversation turns
 --allowedTools <tools> Comma-separated allowed tools
 --disallowedTools <tools> Comma-separated denied tools
 --output-format <fmt> Output: text, json, stream-json
 -v, --verbose Verbose output
 -d, --debug Debug mode
 --version Show version
 -h, --help Show help

Examples

# Use a different model
occ -m claude-opus-4-6 "design a database schema for a blog"
# Print mode (for piping)
occ -p "list all functions in src/" > functions.txt
# Plan mode (read-only, no edits)
occ --permission-mode plan "review the security of auth.js"
# Restrict tools
occ --allowedTools "Read,Glob,Grep" "find all API endpoints"
# With custom system prompt
occ --system-prompt "You are a senior Go developer" "review main.go"

🔧 Interactive Commands

🔨 Tools

⚙️ Configuration

Settings

{
 "model": "claude-sonnet-4-6",
 "permissions": {
 "defaultMode": "auto"
 },
 "hooks": {
 "PreToolUse": [{
 "matcher": "Bash",
 "hooks": [{ "type": "command", "command": "echo 'Running bash...'" }]
 }]
 },
 "autoCompactEnabled": true,
 "alwaysThinkingEnabled": true
}

CLAUDE.md

# Project Rules
- Always use TypeScript
- Follow TDD
- Keep files under 500 lines

Custom Agents

---
name: reviewer
description: Code review specialist
model: claude-sonnet-4-6
tools: [Read, Glob, Grep]
---
You are a thorough code reviewer. Check for bugs, security issues, and style.

Skills

---
name: deploy
description: Deploy to production
---
1. Run tests: npm test
2. Build: npm run build
3. Deploy: ./scripts/deploy.sh

🔐 Multi-Provider Support

# Anthropic (default)
ANTHROPIC_API_KEY=... occ "hello"
# OpenAI
OPENAI_API_KEY=... occ -m gpt-4o "hello"
# Google
GOOGLE_AI_API_KEY=... occ -m gemini-2.5-flash "hello"
# AWS Bedrock
AWS_ACCESS_KEY_ID=... AWS_SECRET_ACCESS_KEY=... occ -m bedrock/claude-sonnet "hello"
# Google Vertex
GOOGLE_APPLICATION_CREDENTIALS=... occ -m vertex/claude-sonnet "hello"

🔗 MCP Integration

// .mcp.json
{
 "mcpServers": {
 "my-server": {
 "command": "npx",
 "args": ["-y", "my-mcp-server"],
 "env": { "API_KEY": "..." }
 }
 }
}

🔍 Background: The Claude Code Source Leak

What ruDevolution Found

⚖️ Legal

📚 Related

📄 License