MCP Calculator Service

A Model-Context-Protocol (MCP) implementation for a calculator service that uses Claude AI to process natural language requests and perform mathematical calculations.

Architecture

The service consists of three main components:

1. Calculator API (calculator-api.js): Handles basic mathematical operations
2. MCP Server (mcp-server.js): Manages LLM integration and tool orchestration
3. MCP Client (mcp-client.js): Provides a user interface for interacting with the service

Setup

1. Install dependencies:

npm install

2. Create a .env file in the root directory with the following variables:

ANTHROPIC_API_KEY=your_api_key_here
PORT=3000
MCP_PORT=3001

Running the Service

You can run all components concurrently:

npm start

Or run them individually:

# Calculator API
npm run start:calculator

# MCP Server
npm run start:mcp

# MCP Client
npm run start:client

Usage

Once the service is running, you can interact with it through the client interface. Here are some example commands:

• "Add 5 and 3"
• "What is 10 plus 20?"
• "Calculate 7.5 + 2.25"
• "Multiply 4 by 6"
• "What is 8 times 3?"

Type "help" for more examples or "exit" to quit.

API Endpoints

Calculator API (Port 3000)

• POST /:operation - Perform mathematical operations (add, subtract, multiply, divide, power)
• GET /health - Health check endpoint

MCP Server (Port 3001)

• GET /tools - List available tools
• POST /execute/:toolId - Execute a specific tool
• POST /agent - Process natural language requests
• GET /health - Health check endpoint

Error Handling

The service includes comprehensive error handling for:

• Invalid mathematical operations
• Division by zero
• Invalid parameter types
• LLM response parsing errors
• Network errors

Dependencies

• @anthropic-ai/sdk: ^0.51.0
• axios: ^1.6.7
• body-parser: ^1.20.2
• cors: ^2.8.5
• dotenv: ^16.4.5
• express: ^4.18.3
• concurrently: ^8.2.2 (dev dependency)