FetchFlight

Elixir port of the Python fast_flights library. Scrapes Google Flights by encoding a query as a protobuf binary, fetching the results page, and returning structured flight data — no API key required.

Installation

def deps do
  [
    {:fetch_flight, "~> 0.1"}
  ]
end

Usage

query = %{
  data: [
    %{
      date: "2026-03-15",
      from_airport: %{code: "SFO"},
      to_airport: %{code: "JFK"},
      max_stops: nil,
      airlines: []
    }
  ],
  seat: :economy,
  trip: :one_way,
  passengers: [:adult]
}

{:ok, {metadata, flights}} = FetchFlight.get_flights(query)

Options

FetchFlight.get_flights(query, language: "en", currency: "USD")

Option	Default	Description
`:language`	`"en"`	BCP 47 language tag
`:currency`	`"USD"`	ISO 4217 currency code

Query fields

Top-level

Field	Type	Values
`:seat`	atom	`:economy`, `:premium_economy`, `:business`, `:first`
`:trip`	atom	`:one_way`, `:round_trip`, `:multi_city`
`:passengers`	`[atom]`	`:adult`, `:child`, `:infant_in_seat`, `:infant_on_lap`
`:data`	`[flight_data]`	One entry per leg

Per leg (data list)

Field	Type	Notes
`:date`	`"YYYY-MM-DD"`	Departure date
`:from_airport`	`%{code: "SFO"}`	IATA origin code
`:to_airport`	`%{code: "JFK"}`	IATA destination code
`:max_stops`	`integer \| nil`	`nil` = any number of stops
`:airlines`	`[String.t()]`	Filter by IATA airline code, e.g. `["UA", "AA"]`

Multi-city example

query = %{
  data: [
    %{date: "2026-04-01", from_airport: %{code: "SFO"}, to_airport: %{code: "LHR"}, max_stops: nil, airlines: []},
    %{date: "2026-04-10", from_airport: %{code: "LHR"}, to_airport: %{code: "CDG"}, max_stops: 0,   airlines: []}
  ],
  seat: :business,
  trip: :multi_city,
  passengers: [:adult, :adult]
}

Output

{:ok, {%FetchFlight.JsMetadata{airlines: [...], alliances: [...]}, flights}}

flights is a list of %FetchFlight.Flights{}, sorted cheapest first:

%FetchFlight.Flights{
  type:     "DL",                      # IATA carrier code
  price:    344,                       # in the requested currency
  airlines: ["Delta"],
  carbon: %FetchFlight.CarbonEmission{
    emission_grams:          284_000,
    typical_on_route_grams:  354_000
  },
  flights: [
    %FetchFlight.SingleFlight{
      from_airport: %FetchFlight.Airport{code: "SFO", name: "San Francisco International Airport"},
      to_airport:   %FetchFlight.Airport{code: "JFK", name: "John F. Kennedy International Airport"},
      departure: %FetchFlight.SimpleDatetime{date: [2026, 3, 15], time: [7, 0]},
      arrival:   %FetchFlight.SimpleDatetime{date: [2026, 3, 15], time: [15, 28]},
      duration_minutes: 328,
      plane_type: "Boeing 767"
    }
  ]
}

SimpleDatetime format

:date — [year, month, day]
:time — [hour, minute], or [hour] when minutes = 0

How it works

Encode — the query is serialized as a protobuf binary (manually encoded, no generated code) and Base64-encoded into the tfs URL parameter.
Fetch — GET https://www.google.com/travel/flights?tfs=...&hl=...&curr=... with realistic browser headers via req.
Parse — floki locates the <script class="ds:1"> tag; jason decodes the embedded JSON payload; specific array indices are navigated to extract flights, prices, and carbon data.

Disclaimer

This library scrapes a public web interface. Google may change the page structure without notice, which could break parsing. It is intended for personal and research use — check Google's Terms of Service before deploying at scale.

License

MIT