Quick Start

npx c2c-mcp init

That's it. Run this in each project directory where you use Claude Code. The two instances will discover each other automatically.

What Happens Next

Once two c2c nodes find each other on the network, you'll see a pairing prompt:

A device named "backend-bob" wants to pair with your Claude instance.
If approved, it will be able to read your current task, see your recent
file changes, and exchange messages with you.
Only approve devices you recognize and trust.

Approve it, and your agents are connected. Trusted peers are remembered -- they'll auto-connect next time.

What Your Agents Can Do

Share Intent

Each agent broadcasts what it's working on. Before your frontend agent changes a fetch call, it can check what the backend agent is doing to that endpoint.

See File Changes

File modifications are tracked in real time. When the backend agent refactors a route, the frontend agent sees the diff -- without pulling from git.

Send Messages

Agents can ask each other questions asynchronously:

"Hey, are you changing the /users response schema? I'm about to update the TypeScript interface on my end."

The other agent picks it up on its next turn and responds.

Tools Reference

Once c2c is active, Claude Code gets these tools:

| Tool | What it does | |------|-------------| | set_plan | Broadcast your current task to all peers | | ask_peer | Send a message to another agent | | check_messages | Read incoming messages | | sync_with_peer | Pull a peer's current plan and recent file changes | | list_peers | See who's connected | | approve_peer | Accept a pairing request | | reject_peer | Decline a pairing request | | list_trusted | See all auto-trusted peers | | untrust_peer | Revoke trust and disconnect a peer |

Setup Options

The One-Liner (Recommended)

npx c2c-mcp init

Detects your project directory, picks an available port, and registers the MCP server with Claude Code. Run it once per project.

Manual Setup

If you need more control:

claude mcp add c2c -s project -- npx c2c-mcp serve \
  --project /path/to/your/project \
  --name "frontend-alice" \
  --port 9100

| Flag | Description | Default | |------|-------------|---------| | --project | Project directory to watch for file changes | Current directory | | --name | Human-readable name for this node | Directory name | | --port | WebSocket port for peer connections | 9100 | | --ignore | Extra glob patterns to ignore (repeatable) | -- |

Remove

npx c2c-mcp remove

Collaboration Skill (Optional)

Copy skill/c2c-protocol.md to your Claude Code skills directory. This teaches Claude to automatically check messages at the start of each turn, announce its plan before working, and sync before modifying shared APIs.

How It Works

Machine A                              Machine B
┌──────────────┐                       ┌──────────────┐
│  Claude Code │                       │  Claude Code │
│      ▲       │                       │      ▲       │
│      │ stdio │                       │      │ stdio │
│      ▼       │                       │      ▼       │
│  ┌────────┐  │    mDNS discovery     │  ┌────────┐  │
│  │  c2c   │◄─┼───────────────────────┼─►│  c2c   │  │
│  │ server │  │    WebSocket link     │  │ server │  │
│  └────────┘  │                       │  └────────┘  │
└──────────────┘                       └──────────────┘

1. Each c2c server broadcasts itself via mDNS (_c2c._tcp.local)
2. When a peer appears, a WebSocket connection is established
3. First-time peers go through a pairing approval flow
4. Approved peers are saved to ~/.c2c/trusted_peers.json for auto-reconnect
5. State is shared on demand -- pull-based, not continuous sync

Works across machines on the same network, or between two terminals on the same machine (just use different ports).

Security

• First-connect approval: New peers always require explicit user confirmation
• Trust persistence: Approved peers are remembered; revoke anytime with untrust_peer
• LAN only: mDNS discovery is limited to your local network
• No cloud relay: All traffic stays on your network

Development

git clone https://github.com/CLCK0622/c2c-mcp.git
cd c2c-mcp
pnpm install
pnpm build
pnpm test

License

MIT