Experimental Project: Two - person Long - polling Chat via MCP Protocol Tool Call Mechanism

MCP Chat

An experimental chat project based on the MCP protocol, implementing long polling chat functions in a two-person room by abusing the MCP tool call mechanism.

Communication tools Developer tools #MCP Protocol #Experimental Project #Chat Tool #Long Polling .Python

rating : 2.5 points

downloads : 4.6K

update time : 2025-07-24

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What is the MCP Chat Server?

This is a chat server based on the Model Context Protocol (MCP), allowing users to conduct real-time message transmission through MCP clients. It uses long polling technology to transmit messages between two users.

How to use the MCP Chat Server?

By running the MCP server and connecting to it, users can create or join rooms and send and receive messages. A client that supports MCP (such as Claude Code) is required for interaction.

Applicable Scenarios

Suitable for simple peer-to-peer chatting, testing the functions of the MCP protocol, and exploring non-traditional communication methods for AI assistants.

Main Features

Room Chat

Supports users to create or join rooms and have one-on-one chats with another user.

Message Sending

Provides the function of sending messages, allowing users to send text information in the chat.

Waiting for Messages

Waits for the other party's messages through a blocking call to achieve a real-time chat-like effect.

Exit Chat

Allows users to exit the current room and end the chat session.

Advantages

Utilizes the existing MCP protocol to implement chat functions without the need for additional development of complex systems.

Suitable for rapid prototype development and testing non-standard uses of the MCP protocol.

Limitations

Relies on long polling technology, which is less efficient than real-time notification mechanisms.

Currently only supports simple chats between two people and does not support multi-user rooms or historical message functions.

How to Use

Start the MCP Server

Run the command in the terminal to start the MCP server.

Connect to the MCP Server

Use a client that supports MCP (such as Claude Code) to connect to the server.

Join or Create a Room

Use the tool in the client to call 'join_room' to join or create a room.

Send and Receive Messages

Use 'send_message' to send messages and 'wait_for_message' to wait for the other party's messages.

Exit Chat

After finishing the chat, use 'leave_chat' to exit the current room.

Usage Examples

Peer-to-Peer Chat

Two users conduct real-time conversations through the MCP server, suitable for testing and demonstration.

Temporary Communication

Use this server when users need to communicate quickly, such as sharing temporary information.

Frequently Asked Questions

Why use the MCP protocol for chatting?

Can it support multi-person chatting?

Why can't I receive messages in real-time?

How to ensure message security?

Related Resources

MCP Official Documentation

Understand the detailed specifications and usage methods of the Model Context Protocol (MCP).

Claude Code Client

A client application that supports the MCP protocol, which can be used to connect and test the MCP chat server.

MCP Chat Server Source Code

View and modify the complete code of the MCP chat server.

MCP Chat Server Demo Video

Watch the usage demonstration of the MCP chat server.

🚀 MCP Chat

Leverage MCP (Model Context Protocol) servers for seamless chat experiences.

This project was initially sparked by the concept of a chat roulette-style interaction using MCP clients such as the Claude Mac app or Claude Code. For simplicity, this proof - of - concept employs a straightforward in - memory room - based system, enabling two users in a single room to exchange messages.

🚀 Quick Start

Prerequisites

Python 3.11+
uv package manager

Steps

Run the MCP server using the SHTTP transport:

# Terminal 1
uv sync
uv run fastmcp run mcp_chat/server.py --transport http

Connect to the MCP server using Claude Code (refer to the demo gif for an example):

# Terminals 2 & 3
claude mcp add --transport http mcp - chat - s project -- http://localhost:8000/mcp
claude # Do this in 2 separate sessions

✨ Features

Room - based Chat: Supports two - user chat in a single room.
Long - polling for Real - time: Utilizes long - polling to achieve real - time chat functionality.

💻 Usage Examples

Basic Usage

The core of the chat functionality lies in the following tools:

join_room: Create or join a room.
send_message: Send a message.
wait_for_message: Wait for messages (blocks until a message arrives).
leave_chat: Leave the room.

The magic happens with wait_for_message, which blocks until a message is received, enabling real - time chat through long - polling.

Advanced Usage

There are several future enhancements planned:

Random Pairing: Implement a chat roulette style random pairing mechanism.
Custom Notifications: Add support for custom notifications for asynchronous messaging.
Multi - user Rooms: Enable multiple users to chat in a single room.
Message History: Provide message history functionality.

📚 Documentation

What is MCP Chat?

MCP is originally designed for AI assistants to call tools. This project repurposes this design to allow humans to chat with each other via tool calls. A long - polling tool is used to wait for messages from the recipient. Currently, custom notifications are not supported by the MCP clients in use, so long - polling is the workaround.

How it Works

The MCP server runs using the SHTTP transport. Users can connect to the MCP server via Claude Code. The long - polling mechanism ensures real - time message reception.