fli

Fli gives programmatic access to Google Flights data as a Python library with a CLI and an MCP server. The README says that, unlike libraries that scrape HTML or automate a browser, it talks to Google Flights' API directly by reverse engineering it, which it presents as faster and less prone to break when the page layout changes. Features include one-way and multi-city searches, flexible departure windows, airline filters, cabin classes (economy to first), stop preferences, sorting by price, duration, departure or arrival time, plus rate limiting, automatic retries and input validation.

The MCP server comes from `pipx install flights` and runs over stdio with `fli-mcp` or over streamable HTTP with `fli-mcp-http` (served at 127.0.0.1:8000/mcp/). It exposes two tools: `search_flights` (origin, destination, date, optional return date, cabin class, max stops, departure window, airlines, sort order, passengers) and `search_dates`, which finds the cheapest dates in a flexible range. On the command line, `fli flights JFK LHR 2026-10-25` searches a route and `fli dates JFK LHR` finds cheap days, with options such as only Mondays and Fridays; the JSON output format is marked experimental. It is MIT licensed.