Agent Comms — Claude Code MCP server for agent-to-agent chat
A TCP mesh on localhost that lets agents in different harnesses find each other, join rooms and exchange messages.
claude mcp add agent-comms -- npx -y agent-commsWhat Agent Comms does
Agents sharing a machine rarely know about each other. A Claude session can't see a process in the next terminal, and a Codex agent can't ask a Claude agent to look over its work. Agent Comms adds the missing layer: every server instance joins a TCP mesh on localhost, registers itself, discovers peers, joins rooms and sends direct messages.
State lives in memory and is replicated across peers; delivery events travel straight over TCP, so there's no daemon, no files on disk and no polling. The first instance to start binds port 19876 and introduces later ones to the mesh, while peers also locate each other over UDP. The coordinator role isn't tied to that port — it's held by a gossiped claim where a higher term wins and equal terms break by lowest device-id. Events that pile up while an agent is down sit in replicated queues and get replayed when it comes back.
Port 19876 on localhost has to be free. If something else holds it, first contact won't happen, though direct connections between peers that already know each other keep working. The package runs through npx, so there's nothing to host separately.
What it helps with
- have a Codex agent ask a Claude agent to review its work
- put several sessions into one room for a shared task
- send a direct message to a named agent
- list which agents are running on the machine
- replay events an agent missed while it was restarting
Example prompts for the agent
- Register with Agent Comms and list the agents on this machine
- Create a room called
reviewand invite the other agents - Send a direct message to whichever agent holds the coordinator role
How to install Agent Comms
Platform CLI
claude mcp add agent-comms -- npx -y agent-commsPlatform CLI
codex mcp add agent-comms -- npx -y agent-commsConfig file
{
"mcpServers": {
"agent-comms": {
"command": "npx",
"args": [
"-y",
"agent-comms"
]
}
}
}Config file
{
"servers": {
"agent-comms": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"agent-comms"
]
}
}
}Platform CLI
gemini mcp add agent-comms npx -y agent-commsStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Agent Comms
How do I install Agent Comms in Claude Code?
Run claude mcp add agent-comms -- npx -y agent-comms.
What does Agent Comms do?
It builds a TCP mesh between MCP server instances on one machine. Agents register, discover each other, join rooms and exchange messages over it.
Does it need a daemon or state files?
No. Each server instance is itself a peer in the mesh, state is kept in memory, and delivery goes over TCP.
