Hello World MCP Server

Welcome to the Hello World MCP Server! This project demonstrates how to set up a server using the Model Context Protocol (MCP) SDK. It includes tools, prompts, and endpoints for handling server-sent events (SSE) and messages.

This project is part of the blog post: Building a TypeScript MCP Server: A Guide for Integrating Existing Services. Visit the blog to learn more about the concepts and implementation details behind this project.

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Features

• MCP Integration: Uses the MCP SDK to create a server with tools and prompts.
• Express Framework: Handles HTTP endpoints for SSE and message communication.
• Environment Configuration: Uses .env files for easy configuration.
• TypeScript Support: Fully typed codebase for better developer experience.

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Prerequisites

Before you begin, ensure you have the following installed:

1. Node.js (v16 or higher) - Download here

2. npm (comes with Node.js) or yarn

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Getting Started

Follow these steps to set up and run the project:

1. Clone the Repository

If you haven't already, clone the repository to your local machine:

git clone https://github.com/your-username/hello-world-mcp-server.git
cd hello-world-mcp-server

2. Install Dependencies

Install the required dependencies using npm or yarn:

npm install

or

yarn install

3. Configure Environment Variables

The project uses a .env file to configure the server's port. A sample .env.example file is provided.

1. Copy the .env.example file to .env:

cp .env.example .env

2. Open the .env file and update the PORT variable if needed. The default is 4000.

PORT=4000

4. Build the Project

Compile the TypeScript code into JavaScript:

npm run build

This will generate the compiled files in the dist directory.

5. Run the Server

Start the server in production mode:

npm start

Alternatively, for development mode with live reloading, use:

npm run dev

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Testing the Server

1. Using the MCP Inspector

The MCP Inspector is a tool to test and inspect your MCP server. You can use it to verify that your tools and prompts are registered correctly.

Run the following command to inspect your server:

npx @modelcontextprotocol/inspector ./dist/server.js

This will open an interactive interface where you can test the tools and prompts registered in your server like below.

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Project Structure

Here’s an overview of the project structure:

hello-world-mcp-server/
├── src/
│   ├── server.ts                     # Main server entry point
│   ├── modules/
│   │   ├── tools.ts                  # Registers MCP tools
│   │   ├── prompts.ts                # Registers MCP prompts
│   │   └── transports.ts             # Handles SSE and message endpoints
├── .env                              # Environment variables
├── .env.example                      # Example environment variables
├── package.json                      # Project metadata and scripts
├── tsconfig.json                     # TypeScript configuration
└── README.md                         # Project documentation

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Troubleshooting

Common Issues

1. Port Already in Use: If you see an error about the port being in use, update the PORT variable in the .env file.

2. TypeScript Errors: Ensure you’ve installed all dependencies and are using the correct Node.js version.

Debugging

Use the following command to debug the server:

npm run dev

This will start the server with live reloading and detailed logs.

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Related Projects

• Ollama Pydantic Project: A counter project implementing an LLM agent that utilizes the tools developed in this project. Learn more about it in the blog post: Integrating MCP Server with a Local LLM Chatbot.

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Contributing

Contributions are welcome! Feel free to open issues or submit pull requests.

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License

This project is licensed under the MIT License. See the LICENSE file for details.