# MCP Test Server

A Model Context Protocol (MCP) server implementation with multiple tools for testing and demonstration purposes.

## Overview

This server provides three main tools:
- **BMI Calculator**: Calculate Body Mass Index from weight and height
- **Weather Service**: Get weather information for any city (with API key support)
- **Echo Tool**: Simple echo functionality for testing

## Features

- Built with TypeScript and Express.js
- Streamable HTTP transport for MCP
- Environment-based configuration
- Hot reload development support
- Modular tool architecture

## Prerequisites

- Node.js (v18 or higher)
- npm or yarn package manager

## Installation

1. Clone or download this repository
2. Install dependencies:
   ```bash
   npm install
   ```

3. Copy the environment example file:
   ```bash
   cp .env.example .env
   ```

4. (Optional) Add your weather API key to `.env`:
   ```
   WEATHER_API_KEY=your_openweathermap_api_key_here
   ```

## Build and Run

### Development Mode
```bash
# Build and start with hot reload
npm run dev
```

### Production Mode
```bash
# Build the project
npm run build

# Start the server
npm start
```

The server will start on `http://localhost:3000` (or the port specified in your `PORT` environment variable).

## API Endpoint

The MCP server is accessible at:
```
POST http://localhost:3000/mcp
```

## Available Tools

### 1. BMI Calculator (`calculate-bmi`)

Calculate Body Mass Index from weight and height.

**Parameters:**
- `weightKg` (number): Weight in kilograms
- `heightM` (number): Height in meters


### 2. Weather Service (`get-weather`)

Get current weather information for a city.

**Parameters:**
- `city` (string): City name
- `country` (string, optional): Country code (e.g., "IN", "US")


### 3. Echo Tool (`echo`)

Simple echo functionality for testing purposes.

**Parameters:**
- `message` (string): Message to echo back


## Testing the Server

### Using MCP Inspector

For a GUI interface to test  MCP server:

1. Start server:
   ```bash
   npm start
   ```

2. In another terminal, run the MCP inspector:
   ```bash
   npm run inspector
   ```

### VS Code Integration

If you're using VS Code with MCP support, add this server to your settings:

```json
{
  "mcp": {
    "servers": {
      "mcp-test-server": {
        "url": "http://localhost:3000/mcp"
      }
    }
  }
}
```

## Project Structure

```
├── src/
│   ├── index.ts          # Main server file
│   └── tools/            # Tool implementations
│       ├── bmi.ts        # BMI calculator tool
│       ├── weather.ts    # Weather service tool
│       └── echo.ts       # Echo tool
├── build/                # Compiled JavaScript files
├── package.json          # Project configuration
├── tsconfig.json         # TypeScript configuration
├── .env.example          # Environment variables example
└── README.md             # This file
```

## Development

### Adding New Tools

1. Create a new tool file in `src/tools/`:
   ```typescript
   import { CallToolResult } from '@modelcontextprotocol/sdk/types.js';
   import { z } from 'zod';

   export const myTool = {
     name: 'my-tool',
     schema: {
       param1: z.string(),
       param2: z.number(),
     },
     handler: async ({ param1, param2 }: { param1: string; param2: number }): Promise<CallToolResult> => {
       return {
         content: [
           {
             type: 'text',
             text: `Result: ${param1} - ${param2}`,
           },
         ],
       };
     },
   };
   ```

2. Import and register it in `src/index.ts`:
   ```typescript
   import { myTool } from './tools/my-tool.js';

   // In the getServer() function:
   server.tool(
     myTool.name,
     'Description of my tool',
     myTool.schema,
     myTool.handler
   );
   ```

### Available Scripts

- `npm run build` - Compile TypeScript to JavaScript
- `npm run watch` - Watch for changes and recompile
- `npm run dev` - Development mode with hot reload
- `npm start` - Start the compiled server
- `npm run inspector` - Launch MCP inspector