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Prerequisites

Before setting up the MCP server, ensure you have:
  • Python 3.10 or higher installed
  • Claude Desktop installed
  • Command line access

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Installation

1

Install Fli

Install Fli using pip or uv:
pip install fli
Or with uv:
uv pip install fli
This installs both the library and the fli-mcp command.
2

Verify installation

Confirm the MCP server is installed correctly:
fli-mcp --help
You should see the help output for the MCP server command.
3

Locate Claude Desktop config

Find your Claude Desktop configuration file:macOS:
~/Library/Application Support/Claude/claude_desktop_config.json
Windows:
%APPDATA%\Claude\claude_desktop_config.json
Linux:
~/.config/Claude/claude_desktop_config.json
4

Add Fli to Claude Desktop

Edit the configuration file to add Fli’s MCP server. Create the file if it doesn’t exist.
{
  "mcpServers": {
    "fli": {
      "command": "fli-mcp",
      "args": []
    }
  }
}
If you’re using uv, you can specify the full path:
{
  "mcpServers": {
    "fli": {
      "command": "uv",
      "args": ["run", "--with", "fli", "fli-mcp"]
    }
  }
}
5

Restart Claude Desktop

Completely quit and restart Claude Desktop for the changes to take effect.The MCP server will start automatically when Claude Desktop launches.
6

Verify connection

In Claude Desktop, start a new conversation and ask:
Can you search for flights?
Claude should respond indicating it has access to the search_flights and search_dates tools.

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Configuration (optional)

You can customize the MCP server behavior using environment variables. Add them to your Claude Desktop configuration: 
{
  "mcpServers": {
    "fli": {
      "command": "fli-mcp",
      "args": [],
      "env": {
        "FLI_MCP_DEFAULT_CURRENCY": "EUR",
        "FLI_MCP_DEFAULT_CABIN_CLASS": "BUSINESS",
        "FLI_MCP_MAX_RESULTS": "10"
      }
    }
  }
}
See the configuration guide for all available options.

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Testing the connection

Try these example queries in Claude Desktop: 
Find flights from JFK to LHR on March 15th, 2026
Claude will use the search_flights tool to return available flights with prices.
What are the cheapest dates to fly from SFO to NRT between 
April 1st and April 30th for a 7-day trip?
Claude will use the search_dates tool to compare prices across the date range.
Show me non-stop business class flights from LAX to CDG 
departing between 6pm and 10pm on March 20th
Claude will apply the appropriate filters to the search.

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Troubleshooting

  • Ensure you completely quit and restarted Claude Desktop (not just closed the window)
  • Check that the fli-mcp command works in your terminal
  • Verify the configuration file path is correct for your operating system
  • Check the Claude Desktop logs for connection errors
  • Verify Fli is installed in your Python environment
  • If using a virtual environment, provide the full path to the fli-mcp command
  • Try the uv-based configuration shown in Step 4
The server has a built-in 10 requests/second limit with automatic retries. If you hit rate limits:
  • Wait a few seconds between searches
  • The server will automatically retry with exponential backoff
  • Consider adding a small delay between multiple consecutive searches

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Next steps

Tool reference

Learn about all available search parameters

Configuration

Customize defaults and behavior

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