Duffel API
Duffel is a self-serve REST API for flights, stays, and payments, with sandbox tokens and official Node, Python, and Ruby SDKs. Pricing is public pay-as-you-go: $3 per flight order plus 1% of order value, no upfront fees. Versioning is explicit and every change lands in a public changelog.
Frequently asked questions
Duffel scores A on the API Report Card. Duffel is a self-serve REST API for flights, stays, and payments, with sandbox tokens and official Node, Python, and Ruby SDKs. Pricing is public pay-as-you-go: $3 per flight order plus 1% of order value, no upfront fees. Versioning is explicit and every change lands in a public changelog.
Duffel has a workable official integration path. Most engineering teams can build against it directly. Open API: self-serve, documented, with SDKs
Duffel is a modern, developer-first travel API platform that lets any business, from a two-person startup to a Fortune 500, sell flights, hotels, cars and ancillaries through a single REST/JSON API instead of integrating directly with legacy GDSs (Amadeus, Sabre, Travelport), airline-direct NDC connections, or hotel wholesalers.
Vertical: Travel & Expense (specifically the Modern Travel API / NDC Aggregation / Flights + Stays Booking sub-vertical). Air search (offer-request → offers across NDC, GDS and LCC content). Air pricing (re-confirm fare on a specific offer before booking, since offers expire ~30 minutes after creation).
Medium-to-large within the modern travel-API category and growing fast; the de facto choice for greenfield 'travel-as-a-feature' builds. Duffel publicly claims 500+ business customers across flights and stays.
Air offer requests: origin/destination, dates, cabin class, passenger types (adt/chd/inf), max connections, slice definitions, supplier timeout.
Duffel is approximately 8 years old (founded 2017, public launch in 2019 via Show HN on Hacker News, Y Combinator S18).
Grades measure one thing: can a customer's engineering team get their own data out programmatically? We check six things (whether a real API exists, how access is gated, data coverage, auth quality, docs and developer experience, and stability) and roll them into a letter grade. Grades get re-verified, and they only move on evidence.