flyr-cli 1.3.1

Search Google Flights from the terminal
Documentation

flyr

crates.io License: GPL-3.0 Rust GitHub stars GitHub last commit

Google Flights from your terminal. Single binary, no API key, no browser.

prompt: find the cheapest round-trip from Helsinki to somewhere warm, departing tomorrow. open the best one in my browser.

agent runs:

flyr search -f HEL -t AYT,NCE,ATH,RAK,LPA,SIN,BKK -d 2026-03-01 --compact --top 1 --currency EUR --return-date 2026-03-08 --open

output:

=== AYT ===
€236 | HEL>SAW>AYT | 7h15m | 1 stop SAW | Pegasus | Mar01 06:30>15:45
=== NCE ===
€260 | HEL>CDG>NCE | 5h50m | 1 stop CDG | Air France | Mar01 09:10>14:00
=== ATH ===
€331 | HEL>AMS>ATH | 8h20m | 1 stop AMS | KLM | Mar01 07:45>18:05
=== RAK ===
€347 | HEL>LIS>RAK | 10h05m | 1 stop LIS | Finnair, TAP | Mar01 11:00>21:05
=== LPA ===
€443 | HEL>LPA | 6h30m | nonstop | Norwegian | Mar01 08:00>14:30
=== SIN ===
€710 | HEL>AMS>SIN | 16h45m | 1 stop AMS | KLM | Mar01 07:45>06:30
=== BKK ===
€859 | HEL>DOH>BKK | 14h20m | 1 stop DOH | Finnair, Qatar | Mar01 17:00>11:20
Opening: https://www.google.com/travel/flights/search?tfs=GhoSCjIwMjYtMDMtMDFqBRIDSEVMcgUSA0xQQRoaEgoyMDI2LTAzLTA4agUSA0xQQXIFEgNIRUxCAQFIAZgBAQ&tfu=EgYIABAAGAA&curr=EUR&hl=en

One command, 7 destinations, ~5k tokens. No browser, no clicking, no cookie banners. Pick the flights you want and the agent opens them directly on Google Flights to book.

Why

Google Flights has no API. The website is slow, requires a browser, and you can only search one route at a time. If you want to compare 10 destinations you're clicking through 10 separate searches, waiting for each page to load, fighting cookie banners.

flyr fixes this. It's a single static binary that scrapes Google Flights directly. Search multiple destinations in one call. Pipe output into scripts, or let an AI agent search dozens of routes and compile results -- like the table above.

Built for people who book flights programmatically -- whether that's a bash loop, a Python script, or an LLM agent that can run shell commands.

Install

cargo install flyr-cli

Requires cmake, perl, and clang for the BoringSSL build (wreq dependency).

Arch: pacman -S cmake perl clang

Usage

flyr search -f HEL -t BKK -d 2026-03-01
flyr search -f LAX -t NRT -d 2026-05-01 --return-date 2026-05-15
flyr search -f HEL -t BKK -d 2026-03-01 --json --currency EUR
flyr search -f HEL -t DXB -d 2026-03-01 --open

Agent mode

flyr is designed for LLM agents. Three flags minimize token consumption:

  • --compact -- one line per flight, pipe-delimited, no box-drawing characters
  • --top N -- only return the N cheapest results
  • -t BCN,ATH,AYT -- multi-destination in a single invocation
flyr search -f HEL -t BCN,ATH,AYT -d 2026-03-01 --compact --top 3 --currency EUR

Before (v1.0): 7 separate invocations, ASCII tables, all results → ~44k tokens. After (v1.1): 1 invocation, compact output, top 3 per destination → ~5k tokens.

An agent can:

  • Search dozens of routes in one call
  • Filter by price, stops, departure time
  • Compare destinations and compile results
  • Open the best options directly in a browser

Multi-destination search

Comma-separate destination codes in -t:

flyr search -f HEL -t BKK,SIN,KUL,HKT,DPS -d 2026-03-01 --compact --top 3 --currency EUR

All destinations are searched concurrently. Output is grouped by destination.

Works with --return-date (each destination gets its own return leg), --top, all output modes.

Cannot be combined with --leg (use separate invocations for multi-city itineraries).

Concurrent searches (advanced)

For more complex scenarios beyond multi-destination, you can still run parallel shell processes:

for dest in BKK SIN KUL HKT DPS; do
  flyr search -f HEL -t $dest -d 2026-03-01 --return-date 2026-03-08 --json --currency EUR &
done | jq -s '[.[] | .flights[0] | {dest: .segments[0].to_airport.code, price, airlines}] | sort_by(.price)'

Localization

Results adapt to any language and currency Google Flights supports:

flyr search -f HEL -t BKK -d 2026-03-01 --currency EUR --lang fi
flyr search -f HEL -t BKK -d 2026-03-01 --currency JPY --lang ja
flyr search -f HEL -t BKK -d 2026-03-01 --currency THB --lang th

flyr search [OPTIONS]

REQUIRED (simple mode):
  -f, --from <IATA>           Departure airport (3-letter IATA code)
  -t, --to <IATA>             Arrival airport (comma-separate for multi-destination)
  -d, --date <YYYY-MM-DD>     Departure date

MULTI-CITY (replaces -f/-t/-d):
  --leg <"DATE FROM TO">      Flight leg, repeatable

TRIP:
  --return-date <YYYY-MM-DD>  Return date (auto-sets round-trip)
  --trip <TYPE>                one-way | round-trip | multi-city  [default: one-way]
  --seat <CLASS>               economy | premium-economy | business | first  [default: economy]

FILTERS:
  --max-stops <N>              0 = nonstop only
  --airlines <AA,DL,...>       Comma-separated IATA codes

PASSENGERS:
  --adults <N>                 [default: 1]
  --children <N>               [default: 0]
  --infants-in-seat <N>        [default: 0]
  --infants-on-lap <N>         [default: 0]

OUTPUT:
  --compact                    One-line-per-flight (recommended for scripts and AI agents)
  --top <N>                   Show only the N cheapest results
  --json                      JSON to stdout
  --pretty                    Pretty-printed JSON to stdout
  --open                      Open results in Google Flights
  --currency <CODE>            [default: USD]
  --lang <CODE>               [default: en]

CONNECTION:
  --proxy <URL>                HTTP or SOCKS5 proxy
  --timeout <SECS>             [default: 30]

Output

Compact (recommended for agents)

$ flyr search -f HEL -t BCN -d 2026-03-01 --compact --top 3 --currency EUR
€199 | HEL>MUC>BCN | 4h45m | 1 stop MUC | Lufthansa | Mar01 12:45>17:30
€215 | HEL>ARN>BCN | 5h20m | 1 stop ARN | SAS | Mar01 08:00>13:20
€312 | HEL>BCN | 3h20m | nonstop | Finnair | Mar01 08:00>11:20

Table (default)

$ flyr search -f HEL -t BKK -d 2026-03-01 --currency EUR
┌───────────────────┬───────────┬──────────────────┬──────────────────┬────────┬────────┬────────────┬───────┐
│ Airlines          │ Route     │ Depart           │ Arrive           │ Dur.   │ Stops  │ Aircraft   │ Price │
├───────────────────┼───────────┼──────────────────┼──────────────────┼────────┼────────┼────────────┼───────┤
│ Finnair           │ HEL → BKK │ 2026-03-01 17:00 │ 2026-03-02 07:15 │ 10h 15 │ Nonstop│ Airbus A350│ €589  │
│ Turkish, THAI     │ HEL → IST │ 2026-03-01 19:00 │ 2026-03-02 05:20 │ 12h 40 │ 1 (IST)│ A321, A350 │ €498  │
│                   │ IST → BKK │                  │                  │        │        │            │       │
└───────────────────┴───────────┴──────────────────┴──────────────────┴────────┴────────┴────────────┴───────┘

JSON

flyr search -f HEL -t BKK -d 2026-03-01 --json --pretty

{
  "flights": [
    {
      "flight_type": "AY",
      "airlines": ["Finnair"],
      "segments": [
        {
          "from_airport": { "code": "HEL", "name": "Helsinki Airport" },
          "to_airport": { "code": "BKK", "name": "Suvarnabhumi Airport" },
          "departure": { "year": 2026, "month": 3, "day": 1, "hour": 17, "minute": 0 },
          "arrival": { "year": 2026, "month": 3, "day": 2, "hour": 7, "minute": 15 },
          "duration_minutes": 675,
          "aircraft": "Airbus A350"
        }
      ],
      "price": 589,
      "carbon": { "emission_grams": 570000, "typical_grams": 690000 }
    }
  ],
  "metadata": {
    "airlines": [{ "code": "AY", "name": "Finnair" }],
    "alliances": [{ "code": "ONEWORLD", "name": "Oneworld" }]
  }
}

flyr search -f HEL -t BKK -d 2026-03-01 --json | jq '.flights | sort_by(.price) | first'

flyr search -f JFK -t LHR -d 2026-04-01 --json | jq '[.flights[] | select(.segments | length == 1)]'

flyr search -f HEL -t BCN -d 2026-03-01 --json | jq '.flights[] | {airlines, price}'

Exit codes

Code Meaning
0 Success
2 Validation error (bad airport code, invalid date, etc.)
3 Network error (timeout, DNS, TLS, proxy)
4 Rate limited or blocked by Google
5 Unexpected HTTP status
6 Parse error (Google changed their page structure)

In --json mode, errors are structured JSON to stdout:

{ "error": { "kind": "invalid_airport", "message": "invalid airport code \"XX\" -- must be exactly 3 letters" } }

In human mode, errors go to stderr.

  1. Query encoding -- Flight parameters are protobuf-encoded (hand-rolled encoder, ~130 LOC) and base64-encoded into the tfs URL parameter, matching what Google Flights expects.

  2. HTTP request -- Uses wreq (reqwest fork) with Chrome 137 TLS fingerprint emulation to avoid bot detection. Pre-loads GDPR consent cookies to bypass the EU consent wall.

  3. HTML parsing -- Extracts the <script class="ds:1"> tag, isolates the data: JSON payload, parses with serde_json.

  4. Payload navigation -- The JSON payload is deeply nested arrays. Flight data lives at payload[3][0][i], with segments, prices, carbon data, and metadata at fixed indices. All access is safe (no panics on missing data).

The crate exposes a public API for use as a library:

use flyr::query::*;
use flyr::fetch::FetchOptions;

let params = QueryParams {
    legs: vec![FlightLeg {
        date: "2026-03-01".into(),
        from_airport: "HEL".into(),
        to_airport: "BKK".into(),
        max_stops: None,
        airlines: None,
    }],
    passengers: Passengers::default(),
    seat: Seat::Economy,
    trip: TripType::OneWay,
    language: "en".into(),
    currency: "USD".into(),
};

params.validate()?;

let result = flyr::search(
    SearchQuery::Structured(params),
    FetchOptions::default(),
).await?;

for flight in &result.flights {
    println!("{}: {} segments, ${}", flight.airlines.join(", "), flight.segments.len(), flight.price.unwrap_or(0));
}

src/
├── main.rs     CLI entry point (clap)
├── lib.rs      Public API: search(query, options) -> Result<SearchResult>
├── proto.rs    Hand-rolled protobuf encoder (~130 LOC)
├── query.rs    Query building, validation, URL param generation
├── fetch.rs    HTTP client with Chrome TLS impersonation + GDPR cookies
├── parse.rs    HTML script extraction + JSON payload navigation
├── model.rs    All data types (Serialize + Debug + Clone)
├── table.rs    Human-readable table rendering with currency symbols
└── error.rs    Error types with actionable messages
tests/
├── cli_test.rs     32 tests -- arg parsing, help output, error messages, exit codes
├── parse_test.rs   13 tests -- script extraction, JSON parsing, edge cases
├── proto_test.rs    6 tests -- byte-level protobuf correctness
└── query_test.rs   23 tests -- validation rules, date handling, leap years, browser URLs

License

GPL-3.0