Simple MCP Server Tutorial

A beginner-friendly Model Context Protocol (MCP) server that demonstrates core MCP concepts with practical tools.

What This Server Does

This MCP server provides two main functionalities:

• Calculator: Basic arithmetic operations (add, subtract, multiply, divide)
• Note Management: Create, read, list, and delete notes

Setup Instructions

1. Install Dependencies

npm install

2. Test the Server

npm start

3. Connect to Claude Desktop

Add this configuration to your Claude Desktop config file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%/Claude/claude_desktop_config.json

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

Replace /path/to/your/server.js with the actual path to your server.js file.

4. Restart Claude Desktop

After saving the config, restart Claude Desktop to load your MCP server.

Available Tools

Calculator

• calculator: Perform arithmetic operations
  • Parameters: operation (add/subtract/multiply/divide), a (number), b (number)

Note Management

• add_note: Create a new note with title and content
• get_note: Retrieve a note by title
• list_notes: Show all note titles
• delete_note: Remove a note by title

Example Usage

Once connected to Claude, you can ask:

• "Calculate 15 + 27"
• "Add a note titled 'Meeting' with content 'Team standup at 2pm'"
• "Show me my note called 'Meeting'"
• "List all my notes"

Understanding MCP

This server demonstrates key MCP concepts:

1. Tools: Functions that LLMs can call to perform actions
2. Schema: JSON schema definitions for tool parameters
3. Transport: Communication layer (stdio in this case)
4. Error Handling: Proper error responses for invalid inputs

File Structure

├── package.json        # Dependencies and scripts
├── server.js          # Main MCP server implementation
└── README.md          # This file