jb-7-jay/learn-mcp-server-mongo

MongoDB MCP Server

A robust Model Context Protocol (MCP) server that provides tools and prompts for interacting with a MongoDB database. Built with Node.js and MongoDB, featuring graceful shutdown handling and comprehensive error management.

Features

• MongoDB integration using Mongoose
• User management tools:
  • create-user: Create a new user
  • get-user: Retrieve user by email
  • list-users: List all users with pagination
• Interactive prompts for guided operations
• Graceful shutdown handling
• Comprehensive error management
• Clean single-file implementation

Prerequisites

• Node.js (Latest LTS version)
• MongoDB (v8.0 or higher)
• Claude for Desktop (latest version)
• Visual Studio Code with Cursor extension (for development)

Development Setup

1. Install MongoDB:

   # Using Homebrew on macOS
   brew tap mongodb/brew
   brew install mongodb-community
   
   # Start MongoDB service
   brew services start mongodb-community
   

2. Install Cursor in VS Code:

   • Open VS Code
   • Go to Extensions (Ctrl+Shift+X)
   • Search for "Cursor"
   • Click Install

3. Clone and Setup:

   git clone <repository-url>
   cd learn-mcp-mongo
   npm install
   

4. Configure Environment:

   cp .env.example .env
   # Edit .env with your MongoDB URI if different from default
   

Quick Start

1. Clone or download this repository

2. Install dependencies:

   npm install
   

3. Configure MongoDB:

   • Make sure MongoDB is running locally (default: mongodb://localhost:27017)
   • Or update the .env file with your MongoDB connection string:

     MONGODB_URI=your_mongodb_connection_string
     

4. Configure Claude for Desktop:

   • Open or create ~/Library/Application Support/Claude/claude_desktop_config.json
   • Add the following configuration:

     {
       "mcpServers": {
         "mcp-mongo": {
           "command": "node",
           "args": ["/absolute/path/to/server.js"]
         }
       }
     }
     

5. Start Claude for Desktop

   • The MCP server will start automatically
   • Look for the "Search and tools" icon to access the tools

Using Cursor with MCP Server

1. Install Cursor (AI Code Editor):

   • Download from https://www.cursor.so/
   • Install and open Cursor on your machine

2. Add MCP Server to Cursor:

   • Open Cursor
   • Go to Settings > Integrations > MCP Servers
   • Click Add MCP Server
   • Fill in:
     • Name: mcp-mongo
     • Command: node
     • Arguments: /absolute/path/to/server.js
     • Working Directory: /absolute/path/to/learn-mcp-mongo
   • Save and enable the integration

3. Use Cursor's AI Features:

   • Open your project folder in Cursor
   • Use /help in the command palette for available AI commands
   • Use /edit, /fix, /doc, and other AI features to interact with your code and MCP tools
   • You can now test, debug, and develop your MCP server directly in Cursor with AI assistance

Usage Examples

Creating a User

Create a new user with:
- name: "John Doe"
- email: "john@example.com"
- age: 30

Finding a User

Get user information for email: john@example.com

Project Structure

learn-mcp-mongo/
├── server.js     # Main server file with all functionality
├── .env          # Environment variables
└── package.json  # Project dependencies and scripts

Available Tools

create-user

Creates a new user in the database.

• Parameters:
  • name: User's full name (string, required)
  • email: User's email address (string, required, unique)
  • age: User's age (number, required)
• Response:

  {
    "_id": "user_id",
    "name": "John Doe",
    "email": "john@example.com",
    "age": 30,
    "createdAt": "2025-06-26T00:00:00.000Z"
  }
  

get-user

Retrieves a user by their email address.

• Parameters:
  • email: User's email address (string, required)
• Response:

  {
    "_id": "user_id",
    "name": "John Doe",
    "email": "john@example.com",
    "age": 30,
    "createdAt": "2025-06-26T00:00:00.000Z"
  }
  

list-users

Lists all users in the database with pagination.

• Parameters:
  • limit: Maximum number of users to return (number, optional, default: 10)
• Response:

  [
    {
      "_id": "user_id",
      "name": "John Doe",
      "email": "john@example.com",
      "age": 30,
      "createdAt": "2025-06-26T00:00:00.000Z"
    },
    // ... more users
  ]
  

Available Prompts

create-new-user

An interactive prompt that guides you through the process of creating a new user by asking for:

1. Full Name
2. Email Address
3. Age

Development Guide

Running the Server

1. Start in Development Mode:

   # Run with inspector for debugging
   npx @modelcontextprotocol/inspector node mcp-server.js
   
   # Or run directly
   npm start
   

2. Using Cursor in VS Code:

   • Open the project in VS Code
   • Use Cursor's AI features:
     • Type /help for Cursor commands
     • Use /edit for code suggestions
     • Use /doc to generate documentation
     • Use /fix to get error fixes

Debugging

1. Check Server Logs:

   # Watch server logs in real-time
   tail -f ~/Library/Logs/Claude/mcp*.log
   

2. MongoDB Operations:

   # Check MongoDB status
   mongosh
   use mcp-mongo
   db.users.find()  # List all users
   

3. Test Tools Manually:

   # Using curl to test tools (when running in HTTP mode)
   curl -X POST http://localhost:3000/tools/list-users
   

Server Features

1. Graceful Shutdown:

   • Handles SIGINT, SIGTERM, SIGHUP signals
   • Closes MongoDB connections properly
   • Logs shutdown process

2. Error Handling:

   • MongoDB connection errors
   • Tool execution errors
   • Uncaught exceptions
   • Unhandled rejections

3. Performance Options:

   • MongoDB connection timeout: 5s
   • Heartbeat frequency: 2s
   • User listing pagination

Troubleshooting

1. Make sure MongoDB is running and accessible
2. Check Claude for Desktop logs at ~/Library/Logs/Claude/mcp*.log
3. Verify the server.js path in claude_desktop_config.json is correct
4. Restart Claude for Desktop after configuration changes