Cheapest Flight Dates API
Compare the lowest fare for every departure date in a window of up to 31 days. Results are date-level estimates; use a separate exact search for flight details and booking links.
Request body
Accepts all one-way parameters except departure_date, airlines_include, airlines_exclude and allow_mixed_carriers, plus:
| Parameter | Type | Required | Description |
|---|---|---|---|
| departure_date_range | object | Yes | Inclusive start and end departure dates (YYYY-MM-DD), spanning 1–31 days. Start cannot be before today at the origin. |
| stay_days | integer | No | Omit or null for one-way fares. For round trips, return this many days (0–365) after each departure. |
| return_time_range | object | No | Filter return flights by hour, as in round-trip search. Requires stay_days. |
Prices reflect your passengers, cabin, stops, bags, time windows and maximum price. Use the same carry_on_bags and checked_bags counts for calendar and exact searches. See baggage requirements.
One-way month
curl -X POST "https://ignav.com/api/fares/cheapest-dates" \
-H "X-Api-Key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"origin":"NYC","destination":"LON","departure_date_range":{"start":"2026-12-01","end":"2026-12-31"},"carry_on_bags":1,"checked_bags":1}'Seven-day round trip, two adults, nonstop
curl -X POST "https://ignav.com/api/fares/cheapest-dates" \
-H "X-Api-Key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"origin":"NYC","destination":"LON","departure_date_range":{"start":"2026-12-01","end":"2026-12-31"},"carry_on_bags":2,"checked_bags":1,"stay_days":7,"adults":2,"max_stops":0,"market":"GB"}'Response
The response has one entry in dates for every requested departure date, in ascending order. Round trips also include return_date. It does not identify the matching flight or include an ignav_id.
{
"origin": "NYC",
"destination": "LON",
"dates": [
{
"departure_date": "2026-12-01",
"return_date": "2026-12-08",
"price": {
"amount": 1178,
"currency": "GBP",
"status": "unverified"
}
},
{
"departure_date": "2026-12-02",
"return_date": "2026-12-09",
"price": null
}
],
"observed_at": "2026-10-18T12:00:00Z"
}price is the lowest qualifying fare for the whole trip and the whole party, in the market's currency, including required taxes and fees. It is null when no qualifying fare was found for that date. Prices are unverified and can change; exact search may return a different price and provides each flight's baggage status. Requests with bags can fail if the requested calendar prices are unavailable.
From dates to booking
Use the fields supported by exact search in a one-way request, replacing departure_date_range with the chosen departure_date. For round trips, use round-trip search and replace stay_days with that date's return_date. Choose an itinerary and pass its ignav_id to booking-links.
Keep both bag counts unchanged when moving from calendar discovery to exact search, then use each itinerary's baggage_pricing to see how bags affect its price.
curl -X POST "https://ignav.com/api/fares/round-trip" \
-H "X-Api-Key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"origin":"NYC","destination":"LON","departure_date":"2026-12-01","return_date":"2026-12-08","adults":2,"carry_on_bags":2,"checked_bags":1,"max_stops":0,"market":"GB"}'Each successful cheapest-dates response counts as one request, however many dates it covers. Exact searches and booking-link requests are billed separately.
Related docs