MCP Streamable HTTP Sample

This repository provides sample code for the Streamable HTTP implementation of the Model Context Protocol (MCP).

Overview

MCP (Model Context Protocol) is a communication protocol between clients and servers that supports multiple communication methods. This sample demonstrates an implementation using the Streamable HTTP method.

Streamable HTTP has the following characteristics:

• Sending messages via HTTP POST requests
• Establishing Server-Sent Events (SSE) streams via HTTP GET requests
• Stateful communication through session management

Features

This sample includes the following features:

• Server-side:

  • Implementation of Streamable HTTP transport
  • Support for multiple client connections
  • Provision of tool functions (echo, add)
  • Session management

• Client-side:

  • Connection to the server
  • Retrieving tool lists
  • Invoking tools

Prerequisites

• Node.js 18.x or higher
• npm or yarn

Installation

# Clone the repository (including submodules)
git clone --recursive https://github.com/moritalous/mcp-streamablehttp-sample.git
cd mcp-streamablehttp-sample

# Install dependencies
npm install

# Set up TypeScript SDK
npm run setup

Build

npm run build

How to Run

Starting the Server

npm run start:server

The server starts on port 3001 by default. You can change the port number by setting the PORT environment variable.

Running the Client

npm run start:client

The client connects to http://localhost:3001/mcp by default. You can change the connection destination by setting the MCP_SERVER_URL environment variable.

Development

Running in development mode:

# Server (development mode)
npm run dev:server

# Client (development mode)
npm run dev:client

Project Structure

mcp-streamablehttp-sample/
├── src/
│   ├── client.ts     # Client implementation
│   └── server.ts     # Server implementation
├── typescript-sdk/   # MCP TypeScript SDK (Git submodule)
├── dist/             # Compiled code
├── package.json      # Project configuration
└── tsconfig.json     # TypeScript configuration

License

MIT

References

• Model Context Protocol Specification
• MCP SDK Documentation

Note: A Japanese version of this README is available at README_ja.md