MCP channel
A lightweight MCP channel server that lets agentic agents discover and communicate with each other through direct messages and named channels. Built for multi-agent orchestration.
Architecture
┌─────────────┐ HTTP/SSE ┌────────────┐ HTTP/SSE ┌─────────────┐
│ Agent │◄────────────────►│ Broker │◄────────────────►│ Agent │
│ Session A │ (channel.ts) │ (broket.ts)│ (channel.ts) │ Session B │
└─────────────┘ └────────────┘ └─────────────┘
Each agent session spawns its own channel.ts MCP server as a subprocess. These servers connect to a shared broker.ts HTTP server that routes messages between them.
Quick Start
1. Install dependencies
bun install
2. Start the broker
The broker must be running before any agent sessions connect:
bun run broker.ts
By default it listens on port 8900. Override with CHANNEL_BROKER_PORT=9000 bun run broker.ts.
3. Start agent sessions
In separate terminals, start agent sessions with different names. For Claude Code:
# Terminal 1
CHANNEL_SESSION_NAME=frontend claude --dangerously-load-development-channels server:channel
# Terminal 2
CHANNEL_SESSION_NAME=backend claude --dangerously-load-development-channels server:channel
# Terminal 3
CHANNEL_SESSION_NAME=coordinator claude --dangerously-load-development-channels server:channel
Each session auto-registers with the broker and can immediately communicate.
Tools Available to the agent
| Tool | Description |
|---|---|
send_message | Send a direct message to a session (by name) or to a channel |
list_sessions | List all registered sessions and their online status |
list_channels | List available channels and their members |
create_channel | Create a named channel for group communication |
join_channel | Join an existing channel |
leave_channel | Leave a channel |
Usage Examples
Direct messaging
Tell one agent session:
"Send a message to the backend session asking it to create the API endpoint for /users"
Channel-based coordination
Tell the coordinator session:
"Create a channel called 'project' and invite the other sessions to coordinate on building the user dashboard"
Multi-agent workflow
- Start a "coordinator" session and tell it the overall plan
- Start "frontend" and "backend" sessions
- The coordinator creates a channel, and instructs each agent on their role
- Agents communicate through the channel to coordinate their work
Configuration
| Environment Variable | Default | Description |
|---|---|---|
CHANNEL_SESSION_NAME | session-<random> | Human-readable name for this session |
CHANNEL_BROKER_URL | http://127.0.0.1:8900 | Broker server URL |
CHANNEL_BROKER_PORT | 8900 | Port for the broker (broker.ts only) |
How It Works
- Broker (
broker.ts): A lightweight HTTP server that maintains a registry of sessions, manages named channels, and routes messages via SSE streams - Channel MCP Server (
channel.ts): An MCP server that agent spawns as a subprocess. It registers with the broker, opens an SSE connection for inbound messages, and exposes tools for sending messages - Message delivery: When the agent calls
send_message, the MCP server POSTs to the broker, which pushes the message via SSE to the recipient's MCP server, which delivers it to the recipient's agent session as a<channel>notification