Lemonade Stand

🚀 Lemonade Stand MCP Server

A simple, working example of a Model Context Protocol (MCP) server that allows you to play the classic Lemonade Stand game through Claude Desktop.

🚀 Quick Start

Prerequisites

• Node.js (v20.11.1 or higher recommended)
• Claude Desktop
• npm (comes with Node.js)

Steps

1. Clone this repository:

   git clone https://github.com/yourusername/Lemonade-Stand-MCP-Server.git
   cd Lemonade-Stand-MCP-Server
   

2. Install dependencies:

   npm install
   

3. Locate your Claude Desktop configuration file:

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

4. Configure Claude Desktop:

   {
     "mcpServers": {
       "lemonade-stand": {
         "command": "node",
         "args": [
           "/absolute/path/to/Lemonade-Stand-MCP-Server/server.js"
         ]
       }
     }
   }
   

5. Restart Claude Desktop.

6. Now you should see a hammer icon in Claude Desktop, indicating that the MCP server is connected!

✨ Features

• 🌤️ Dynamic weather system affecting sales
• 💰 Business simulation, including supply and demand
• 📊 Pricing strategies and inventory management
• 🏁 14-day game cycle with profit tracking
• 🎮 Fully playable through Claude Desktop

💻 Usage Examples

How to Play the Game

To start the game, follow these steps:

1. Run in the terminal or command prompt:

   node server.js
   

2. Open Claude Desktop and navigate to the "Tools" menu.

3. Select "Lemonade Stand MCP Server".

4. Start playing with the AI!

📚 Documentation

Configuration Examples

Windows Example:

{
  "mcpServers": {
    "lemonade-stand": {
      "command": "node",
      "args": [
        "C:\\path\\to\\Lemonade-Stand-MCP-Server\\server.js"
      ]
    }
  }
}

macOS Example:

{
  "mcpServers": {
    "lemonade-stand": {
      "command": "node",
      "args": [
        "/Users/yourusername/path/Lemonade-Stand-MCP-Server/server.js"
      ]
    }
  }
}

Troubleshooting

Problem 1: Unable to start the server

• Symptom: The terminal displays errors such as "Module not found".
• Solution:
  • Ensure you have cloned the repository and run npm install.
  • Check if the path is correct.

Problem 2: Claude Desktop does not detect the server

• Symptom: You cannot see "Lemonade Stand MCP Server" in the "Tools" menu.
• Solution:
  • Ensure the configuration file has been edited correctly.
  • Restart Claude Desktop.

Development

To modify this project, follow these steps:

1. Modify the logic in server.js to add new features or change existing ones.
2. Run node server.js in the terminal to test the changes.
3. Restart Claude Desktop to load the updates.

Project Structure

Lemonade-Stand-MCP-Server/
├── server.js              # Main MCP server implementation
├── package.json           # Node.js dependencies
└── README.md             # This file

How It Works

This MCP server implements a simple game loop:

1. The server maintains the game state in memory.
2. Each tool represents a game operation (purchase, sale, etc.).
3. When Claude calls a tool, the server updates the game state.
4. The result is returned to Claude in JSON format.
5. Claude analyzes the result and decides the next action.

This demonstrates how MCP can be used to create interactive experiences where AI models can maintain state, make decisions, and interact with complex systems.

🔧 Technical Details

What is MCP?

The Model Context Protocol (MCP) is an open standard that enables AI models like Claude to interact with external data sources and tools. This server demonstrates how MCP works by implementing the classic Lemonade Stand game as a set of tools that can be used through Claude Desktop.

🤝 Contribution

If you have any suggestions for improvement or find any issues, feel free to open an issue or submit a pull request!

📄 License

MIT

Built as an example of a practical application of the Model Context Protocol.