basic-math-mcp by benincasantonio - MCP Server

Basic Math MCP Server

A simple Model Context Protocol (MCP) server that provides basic mathematical operations. This server demonstrates how to create and expose tools via the MCP protocol.

Features

This MCP server provides four basic mathematical operations:

add: Add two numbers
subtract: Subtract two numbers
multiply: Multiply two numbers
divide: Divide two numbers

Prerequisites

Node.js
npm

Installation

npm install

Usage

The server communicates via stdin/stdout using JSON-RPC 2.0 protocol. Below are examples of how to interact with the server using command-line tools.

Initialize the Server

Before using the server, you should initialize it to establish the protocol version and capabilities:

echo '{"jsonrpc": "2.0", "id": 1, "method": "initialize", "params": {"protocolVersion": "2024-11-05", "capabilities": {}, "clientInfo": {"name": "test-client", "version": "1.0.0"}}}' | node mcp.js | jq

Example Response:

{
  "result": {
    "protocolVersion": "2024-11-05",
    "capabilities": {
      "tools": {
        "listChanged": true
      }
    },
    "serverInfo": {
      "name": "basic-math-mcp",
      "version": "1.0.0",
      "description": "A basic math MCP server"
    }
  },
  "jsonrpc": "2.0",
  "id": 1
}

List Available Tools

To see all available tools and their schemas:

echo '{"jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {}}' | node mcp.js | jq

Example Response:

{
  "result": {
    "tools": [
      {
        "name": "add",
        "title": "Addition tool",
        "description": "Add two numbers",
        "inputSchema": {
          "type": "object",
          "properties": {
            "a": {
              "type": "number"
            },
            "b": {
              "type": "number"
            }
          },
          "required": ["a", "b"],
          "additionalProperties": false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        "name": "subtract",
        "title": "Subtraction tool",
        "description": "Subtract two numbers",
        "inputSchema": {
          "type": "object",
          "properties": {
            "a": {
              "type": "number"
            },
            "b": {
              "type": "number"
            }
          },
          "required": ["a", "b"],
          "additionalProperties": false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        "name": "multiply",
        "title": "Multiplication tool",
        "description": "Multiply two numbers",
        "inputSchema": {
          "type": "object",
          "properties": {
            "a": {
              "type": "number"
            },
            "b": {
              "type": "number"
            }
          },
          "required": ["a", "b"],
          "additionalProperties": false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        "name": "divide",
        "title": "Division tool",
        "description": "Divide two numbers",
        "inputSchema": {
          "type": "object",
          "properties": {
            "a": {
              "type": "number"
            },
            "b": {
              "type": "number"
            }
          },
          "required": ["a", "b"],
          "additionalProperties": false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      }
    ]
  },
  "jsonrpc": "2.0",
  "id": 1
}

Call a Tool

To execute a specific tool, use the tools/call method with the tool name and arguments:

Addition Example

echo '{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "add", "arguments": {"a": 10, "b": 2}}}' | node mcp.js | jq

Example Response:

{
  "result": {
    "content": [
      {
        "type": "text",
        "text": "12"
      }
    ]
  },
  "jsonrpc": "2.0",
  "id": 1
}

Subtraction Example

echo '{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "subtract", "arguments": {"a": 10, "b": 2}}}' | node mcp.js | jq

Multiplication Example

echo '{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "multiply", "arguments": {"a": 10, "b": 2}}}' | node mcp.js | jq

Division Example

echo '{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "divide", "arguments": {"a": 10, "b": 2}}}' | node mcp.js | jq

Technical Details

Dependencies

@modelcontextprotocol/sdk: MCP SDK for building MCP servers
zod: Schema validation library

Protocol

This server implements the Model Context Protocol (MCP) using:

Transport: stdio (stdin/stdout)
Protocol: JSON-RPC 2.0
Protocol Version: 2024-11-05

Input Schema

All mathematical operations accept two parameters:

a (number, required): The first operand
b (number, required): The second operand

Output Format

All tools return results in the following format:

{
  "result": {
    "content": [
      {
        "type": "text",
        "text": "<result>"
      }
    ]
  },
  "jsonrpc": "2.0",
  "id": <request-id>
}

License

MIT