Duffel API
Duffel API Integration Guide for Flight NDC Distribution
Modern airline API connectivity for real-time seat maps, ancillaries, and instant ticketing
By Project OTA | 24 Aug, 2026 | 7 min read
Duffel API provides a modern developer-first interface for NDC flight distribution, enabling OTAs to search, book, and service direct airline content without legacy GDS friction.
What Duffel API provides for modern OTAs
Duffel is a leading travel technology API platform that simplifies airline NDC (New Distribution Capability) and direct-connect flight inventory distribution. Instead of writing separate carrier connections or dealing with complex legacy formats, developers use Duffel's RESTful JSON APIs to query live offers, reserve seats, attach ancillaries, create hold orders, and issue e-tickets.
For online travel agencies (OTAs) and travel startups, Duffel eliminates the long accreditation delays and high setup costs of legacy GDS environments. You can search fares across dozens of major full-service and low-cost carriers (including British Airways, American Airlines, Emirates, Lufthansa, Transavia, and Vueling) with unified schema and real-time response times.
Architecture of a Duffel API integration flow
A production-grade Duffel flight integration follows a standard lifecycle: Offer Requests → Offer Selection → Seat Map & Ancillaries Selection → Order Creation & Payment → Ticket Issue → Order Servicing. First, your backend sends an `/air/offer_requests` call specifying origin, destination, departure date, passenger types, and cabin class.
Duffel returns a list of offers containing itemised baggage allowances, refundability conditions, and fare brand rules. Before checkout, you can call `/air/seat_maps` to fetch interactive seat graphics with pricing per seat tier. Once passenger details and payment are validated, POST `/air/orders` creates the firm booking and returns official airline PNR references.
Managing seats, baggage, and ancillary revenue
One of the biggest commercial benefits of Duffel NDC integration is ancillary upsell capability. Traditional GDS builds often obscure extra baggage, lounge access, or paid seat assignments, requiring complex EMD (Electronic Miscellaneous Document) issuing logic. Duffel normalises ancillary services into the main offer object.
Your booking engine frontend can display interactive aircraft seat layouts, show real-time seat prices (e.g. extra legroom vs standard), and allow travelers to select paid checked bags during checkout. This increases Average Order Value (AOV) and customer satisfaction.
Order servicing: Changes, cancellations, and refunds
Flight distribution does not stop at booking. Post-booking servicing is critical for operational efficiency. Duffel provides dedicated API endpoints for order changes (`/air/order_change_requests`) and cancellations (`/air/order_cancellation_requests`).
When a customer requests a change or cancellation, your system can calculate penalty fees, refund eligibility, and price differences in real time through Duffel's servicing API without manual agent intervention or airline call-center queues.
Combining Duffel with GDS and hotel suppliers
High-volume OTAs rarely rely on a single supplier. The optimal travel tech stack uses Duffel for NDC and LCC content, a GDS (such as Amadeus or Sabre) for legacy interline routes, and hotel aggregators (such as HotelBeds or RateHawk) for accommodation.
Project OTA designs multi-supplier normalization layers that merge Duffel flight offers into your main search results page, giving users maximum route coverage and competitive pricing.
Frequently Asked Questions
Is IATA accreditation required to use Duffel API?
No! Duffel allows non-IATA travel agencies and tech platforms to access airline content and issue tickets using Duffel's own merchant credentials or agency partner models.
Which airlines are supported on Duffel?
Duffel supports dozens of major airlines including British Airways, Lufthansa, American Airlines, Emirates, Qatar Airways, Air France, KLM, EasyJet, Vueling, and many more, with new carriers added regularly.
How fast is Duffel's search response time?
Duffel's search API is optimized for speed, typically returning normalized NDC offers in under 2 to 3 seconds, making it ideal for modern high-converting B2C booking flows.
Key Takeaways
- Duffel provides developer-first REST JSON APIs for NDC and LCC airline distribution.
- Access rich seat maps, extra baggage, hold orders, and instant ticket issue in one flow.
- Integrates easily into multi-source booking engines alongside traditional GDS channels.
Project OTA specializes in Duffel API flight integration — building high-speed NDC booking engines with live seat maps, ancillary upsells, and automated post-booking workflows.
Talk to Project OTA