Phone-a-Friend MCP

An MCP server enabling Claude Code instances to communicate in real-time. One instance enters "listening mode" while another initiates contact with a specific intent.

Architecture

┌─────────────────────────────────────────┐
│      paf-hub (TCP server)               │
│      localhost:7777                     │
└─────────────────────────────────────────┘
         ▲                    ▲
         │ TCP                │ TCP
         │                    │
   Claude Tab 1          Claude Tab 2
   (Listener)            (Caller)

Installation

cd ~/.claude/mcps/phone-a-friend
pip install -e .

Usage

Step 1: Start the Hub

paf-hub

Step 2: Configure Claude Code

Add to ~/.claude/settings.json:

{
  "mcpServers": {
    "phone-a-friend": {
      "command": "python",
      "args": ["-m", "phone_a_friend.server"],
      "cwd": "/Users/YOUR_USERNAME/.claude/mcps/phone-a-friend/src"
    }
  }
}

Step 3: Use It

Tab 1 (Listener):

"Listen for questions. You're the auth expert."

→ paf(action="listen", session_name="auth-expert", description="Expert on auth") → Blocks waiting...

Tab 2 (Caller):

"Ask the auth expert about token refresh."

→ paf(action="list_sessions") → sees "auth-expert" → paf(action="connect", target_session="auth-expert", intent="Token refresh", my_name="feature-dev") → paf(action="send", target_session="auth-expert", message="How handle expired tokens?", my_name="feature-dev") → paf(action="wait_response", my_name="feature-dev") → blocks for answer

Tab 1 receives, responds: → Listener unblocks with question → paf(action="respond", session_name="auth-expert", message="Use sliding window...") → paf(action="listen", ...) → back to waiting

Tool Reference

Single tool paf with actions:

| Action | Parameters | Description | |--------|------------|-------------| | listen | session_name, description | Block waiting for messages | | list_sessions | (none) | List active listeners | | connect | target_session, intent, my_name | Connect with intent | | send | target_session, message, my_name | Send message | | wait_response | my_name | Block for reply | | respond | session_name, message | Reply to caller | | end_session | session_name | Close session |

Conversation Flow

Listener                              Caller
────────                              ──────
listen() [blocks]
                                      connect(intent)
                                      send(question)
[receives question]
respond(answer)
                                      wait_response() → answer
listen() [blocks]                     send(follow_up)
[receives follow_up]
...

MCP Servers