🛫 Fli - Flight Search MCP Server and Library

A powerful Python library that provides programmatic access to Google Flights data with an elegant CLI interface. Search flights, find the best deals, and filter results with ease.

🚀 What makes fli special? Unlike other flight search libraries that rely on web scraping, Fli directly interacts with Google Flights' API through reverse engineering. This means:

• Fast: Direct API access means faster, more reliable results
• Zero Scraping: No HTML parsing, no browser automation, just pure API interaction
• Reliable: Less prone to breaking from UI changes
• Modular: Extensible architecture for easy customization and integration

MCP Server

pipx install flights

# Run the MCP server on STDIO
fli-mcp

# Run the MCP server over HTTP (streamable)
fli-mcp-http  # serves at http://127.0.0.1:8000/mcp/

Connecting to Claude Desktop

{
  "mcpServers": {
    "fli": {
      "command": "/Users/<user>/.local/bin/fli-mcp"
    }
  }
}

Note: Replace <user> with your actual username. You can also find the path to the MCP server by running which fli-mcp in your terminal.

MCP Tools Available

The MCP server provides two main tools:

Tool	Description
search_flights	Search for flights on a specific date with detailed filters
search_dates	Find the cheapest travel dates across a flexible date range

search_flights Parameters

Parameter	Type	Description
origin	string	Departure airport IATA code(s) — comma-separated for multi
destination	string	Arrival airport IATA code(s) — comma-separated for multi
departure_date	string	Travel date in YYYY-MM-DD format
return_date	string	Return date for round trips (optional)
cabin_class	string	ECONOMY, PREMIUM_ECONOMY, BUSINESS, or FIRST
max_stops	string	ANY, NON_STOP, ONE_STOP, or TWO_PLUS_STOPS
departure_window	string	Time window in 'HH-HH' format (e.g., '6-20')
airlines	list	Filter by airline codes (e.g., ['BA', 'AA'])
exclude_airlines	list	Airline IATA codes to exclude (e.g., ['DL', 'B6'])
alliance	list	Restrict to alliances: ONEWORLD, SKYTEAM, STAR_ALLIANCE
exclude_alliance	list	Alliance names to exclude from results
min_layover	int	Minimum layover duration in minutes (multi-stop only)
max_layover	int	Maximum layover duration in minutes (multi-stop only)
top_n	int	Round-trip only: outbound options expanded into return flights (default 5, 1-10)
currency	string	ISO 4217 code (e.g. 'EUR', 'JPY') — flows to curr= param
language	string	BCP-47 language code (e.g. 'en-GB') — flows to hl= param
country	string	ISO 3166-1 alpha-2 country code (e.g. 'GB') for gl= param
sort_by	string	CHEAPEST, DURATION, DEPARTURE_TIME, or ARRIVAL_TIME
passengers	int	Number of adult passengers
children	int	Number of children (ages 2-11)
infants_in_seat	int	Number of infants (under 2) occupying their own seat
infants_on_lap	int	Number of lap infants (under 2, no seat)

Total travelers (passengers + children + infants_in_seat + infants_on_lap) must be between 1 and 9, and infants_on_lap cannot exceed passengers.

A round trip costs 1 + top_n page fetches (one outbound search, plus one per outbound candidate expanded into return flights), so top_n is capped at 10. Round-trip results all from one airline? Raise top_n, or sort differently — the default sort only ever expands the cheapest top_n outbounds, which are often the same carrier.

search_dates Parameters

Parameter	Type	Description
origin	string	Departure airport IATA code(s) — comma-separated for multi
destination	string	Arrival airport IATA code(s) — comma-separated for multi
start_date	string	Start of date range in YYYY-MM-DD format
end_date	string	End of date range in YYYY-MM-DD format
trip_duration	int	Trip duration in days (for round-trips)
is_round_trip	bool	Whether to search for round-trip flights
cabin_class	string	ECONOMY, PREMIUM_ECONOMY, BUSINESS, or FIRST
max_stops	string	ANY, NON_STOP, ONE_STOP, or TWO_PLUS_STOPS
departure_window	string	Time window in 'HH-HH' format (e.g., '6-20')
airlines	list	Filter by airline codes (e.g., ['BA', 'AA'])
exclude_airlines	list	Airline IATA codes to exclude
alliance	list	Restrict to alliances: ONEWORLD, SKYTEAM, STAR_ALLIANCE
exclude_alliance	list	Alliance names to exclude
min_layover	int	Minimum layover duration in minutes