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

Related MCP server: Calculator MCP

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)