Party Time MCP

🚀 Party Time MCP Server

A simple MCP server that responds with "It's Party Time" when asked for the current time.

🚀 Quick Start

This is a straightforward implementation of the MCP protocol, reading directly from standard input and writing to standard output. It registers a single tool named get-time and always responds with "It's Party Time" when this tool is invoked. The server implements the MCP protocol, processes JSON - RPC messages, and provides appropriate responses.

✨ Features

• Implements the MCP protocol, handling JSON - RPC messages and responding appropriately.
• Registers a single tool get-time and responds with "It's Party Time".

📦 Installation

macOS Installation Instructions

1. Build the Executable

First, build the executable:

mix deps.get
mix escript.build

This will create an executable named party_time_mcp in the project directory. Ensure it has execution permissions:

chmod +x ./party_time_mcp

2. Configure Claude Desktop

1. Open your Claude configuration file:

nano ~/.config/claude/settings.json

2. Add the following content to the end of the file to enable experimental features:

{
  "experimental_features": {
    "custom_mcp_server": true
  }
}

3. Save and exit the editor.

3. Start Claude Desktop

After starting Claude Desktop, it will automatically connect to the specified MCP server. By default, it looks for the server at localhost:5001.

💻 Usage Examples

Testing

To verify that your MCP server is working correctly, you can run the following command:

curl -X POST http://localhost:5001 -H "Content-Type: application/json" -d '{"jsonrpc": "2.0", "method": "tools/list"}'

If everything is working correctly, you should see a response similar to the following:

{
  "jsonrpc": "2.0",
  "result": ["get-time"],
  "id": "some-id"
}

🔧 Technical Details

Recent Fixes

Notification Handling

The server has been updated to correctly handle the notifications/initialized message sent by Claude Desktop. This message is sent by the client to confirm receipt of the server/initialized notification. Changes made:

• Added support for the notifications/initialized message.
• The server now correctly handles this notification without errors.

JSON Parsing Errors

The server has been updated to fix JSON parsing errors that occurred in Claude Desktop. The problem was caused by the server outputting log messages to standard output, which mixed with the JSON responses and confused the JSON parser. Changes made:

• Disabled all logging to avoid interfering with JSON output.
• Only clean JSON responses are now sent to standard output.
• Removed duplicate startup messages.
• Added a newline after each JSON response to improve parsing.

Mix.env() Error Fix

The server has been updated to fix the UndefinedFunctionError: function Mix.env/0 is undefined error that occurred at runtime. This issue was due to the Mix module not being available in the escript. Changes made:

• Replaced the runtime Mix.env() call with a compile - time constant.
• The server now correctly determines whether it is in test mode without relying on Mix.

📚 Documentation

Troubleshooting

If you encounter issues related to the Party Time MCP server, please refer to the following common problems and solutions:

UndefinedFunctionError: function Mix.env/0 is undefined

If you see an error message like this, it means the executable was built incorrectly. This error occurs because the Mix module is not available in the escript. Solution:

mix escript.build

Permission Issues

If you get a "permission denied" error when trying to run the executable, give it execution permissions:

chmod +x ./party_time_mcp

Configuration File Issues

If the server cannot find or read the configuration file, check if the file exists and has the correct permissions.

JSON Errors

If you see JSON parsing errors, ensure that the messages sent to the server are in valid JSON - RPC 2.0 format. The server expects messages in the following format:

{
  "jsonrpc": "2.0",
  "id": "some-id",
  "method": "method-name",
  "params": {}
}

For notifications that do not require a response (messages without a reply), the id field should be omitted:

{
  "jsonrpc": "2.0",
  "method": "notification-name"
}