Flight Search MCP Server

A reliable Model Context Protocol (MCP) server for searching flights using the SerpAPI Google Flights engine. This server provides real-time flight search capabilities for both one-way and round-trip flights. Works well with claude ai desktop

✈️ Features

• Real-time flight search using SerpAPI Google Flights
• One-way and round-trip flight support
• Multiple flight options with pricing, timing, and airline details
• JSON-RPC 2.0 compliant MCP protocol implementation
• Easy integration with Claude and other MCP clients
• Robust error handling and logging

🚀 Quick Start

Prerequisites

• Python 3.7 or higher
• SerpAPI account and API key (Get one here)
• MCP-compatible client (Claude, etc.)

Installation

1. Clone or download the server file:

mkdir -p ~/tools/flightsearch
# Copy flight_search_server.py to ~/tools/flightsearch/

2. Install dependencies:

pip install requests

3. Get your SerpAPI key:
   • Sign up at SerpAPI
   • Get your API key from the dashboard

Configuration

Add the following to your MCP client configuration:

{
  "flightsearch": {
    "command": "python3",
    "args": [
      "/path/to/your/tools/flightsearch/flight_search_server.py",
      "--connection_type", 
      "stdio"
    ],
    "env": {
      "SERP_API_KEY": "your_serpapi_key_here"
    }
  }
}

For Claude Desktop, add this to your claude_desktop_config.json:

{
  "mcpServers": {
    "flightsearch": {
      "command": "python3",
      "args": [
        "/Users/yourusername/tools/flightsearch/flight_search_server.py",
        "--connection_type", 
        "stdio"
      ],
      "env": {
        "SERP_API_KEY": "your_serpapi_key_here"
      }
    }
  }
}

📖 Usage

Available Tools

search_flights

Search for flights between airports.

Parameters:

• origin (required): Origin airport code (e.g., "JFK", "LAX")
• destination (required): Destination airport code (e.g., "JFK", "LAX")
• outbound_date (required): Departure date in YYYY-MM-DD format
• return_date (optional): Return date for round-trip flights in YYYY-MM-DD format

Examples:

# One-way flight
search_flights(origin="JFK", destination="LAX", outbound_date="2025-07-01")

# Round-trip flight  
search_flights(origin="JFK", destination="LAX", outbound_date="2025-07-01", return_date="2025-07-08")

server_status

Check if the flight search server is running.

Parameters: None

Sample Response

{
  "status": "success",
  "origin": "JFK",
  "destination": "LAX", 
  "outbound_date": "2025-07-01",
  "return_date": null,
  "trip_type": "one_way",
  "flights": [
    {
      "price": 199,
      "departure_time": "2025-07-01 08:40",
      "arrival_time": "2025-07-01 11:45", 
      "airline": "Delta",
      "duration": 365,
      "stops": 0
    },
    {
      "price": 204,
      "departure_time": "2025-07-01 09:00",
      "arrival_time": "2025-07-01 12:00",
      "airline": "JetBlue", 
      "duration": 360,
      "stops": 0
    }
  ]
}

🔧 Development

Running Tests

Test the server directly:

# Set environment variable
export SERP_API_KEY="your_api_key"

# Run the server  
python3 flight_search_server.py --connection_type stdio

Protocol Testing

The server implements JSON-RPC 2.0 and supports these methods:

• initialize - Initialize the MCP connection
• tools/list - List available tools
• tools/call - Execute a tool
• ping - Health check
• notifications/initialized - Initialization notification

Logging

The server logs to stderr for debugging:

# View logs while running
python3 flight_search_server.py --connection_type stdio 2>debug.log

🐛 Troubleshooting

Common Issues

1. "API request failed: 400 Client Error"

• Verify your SerpAPI key is valid
• Check that airport codes are correct (use IATA codes like "JFK", "LAX")
• Ensure date format is YYYY-MM-DD

2. "SERP_API_KEY environment variable not set"

• Make sure the API key is properly set in your MCP configuration
• Verify the environment variable name is exactly SERP_API_KEY

3. "JSON-RPC schema validation errors"

• Restart your MCP client to reload the server
• Check that you're using the latest version of the server

4. No flights found

• Try different airport codes or dates
• Some routes may not be available for the selected date
• Check SerpAPI documentation for supported airports

Debug Mode

Enable debug logging:

# Add to the top of flight_search_server.py
logging.basicConfig(level=logging.DEBUG, stream=sys.stderr)

📝 API Limitations

• SerpAPI Rate Limits: Check your SerpAPI plan for request limits
• Flight Data: Results depend on Google Flights data availability
• Date Range: Future dates only (cannot search past flights)
• Airport Codes: Must use valid IATA airport codes

🤝 Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

Development Setup

# Clone the repo
git clone https://github.com/yourusername/flight-search-mcp.git
cd flight-search-mcp

# Install dependencies
pip install requests

# Run tests
python3 test_mcp_protocol.py
python3 test_flight_search.py

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• SerpAPI for providing the Google Flights API
• Anthropic for the MCP protocol specification
• The open-source community for inspiration and feedback

📞 Support

• Issues: Open an issue on GitHub
• Questions: Check the SerpAPI documentation
• MCP Protocol: See Anthropic's MCP documentation

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