Setup

Prerequisites

Before setting up the MCP server, ensure you have:

Python 3.10 or higher installed
Claude Desktop installed
Command line access

Installation

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.

Verify installation

Confirm the MCP server is installed correctly:

fli-mcp --help

You should see the help output for the MCP server command.

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

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"]
    }
  }
}

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.

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.

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.

Testing the connection

Try these example queries in Claude Desktop:

Search for specific flights

Find flights from JFK to LHR on March 15th, 2026

Claude will use the search_flights tool to return available flights with prices.

Find cheapest dates

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.

Complex filters

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.

Troubleshooting

Claude doesn't see the tools

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

Command not found error

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

Rate limiting errors

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

Next steps

Tool reference

Learn about all available search parameters

Configuration

Customize defaults and behavior

Get Started

MCP Server

CLI Usage

Python Library

Guides

Prerequisites

Installation

Configuration (optional)

Testing the connection

Troubleshooting

Next steps

Tool reference

Configuration

​Prerequisites

​Installation

​Configuration (optional)

​Testing the connection

​Troubleshooting

​Next steps

Tool reference

Configuration

Prerequisites

Installation

Configuration (optional)

Testing the connection

Troubleshooting

Next steps