The airline distribution landscape has never been more fragmented. In 2026, there are three distinct channels through which flights get booked — each with radically different economics, coverage, and technical requirements. If you're building a travel product, understanding these layers isn't optional. It's the foundation of your entire architecture.
Tier 1: The GDS — The Legacy Backbone
Global Distribution Systems — Amadeus, Sabre, and Travelport — have been the backbone of flight distribution for over 50 years. They aggregate content from hundreds of airlines into a single searchable system, and they remain the most comprehensive source of full-service carrier inventory.
The GDS model works like this: airlines push their schedules, fares, and availability into the GDS. Travel agencies, corporate booking tools, and online travel agents (OTAs) query the GDS to search and book flights. The GDS charges a booking fee — typically $2-6 per segment — which is paid by the airline or split between airline and agency.
Pros of GDS:
- Broadest coverage of full-service carriers worldwide
- Mature, battle-tested systems with high reliability
- Rich fare rules, interline agreements, and codeshare support
- Deep integration with corporate travel management tools
Cons of GDS:
- Expensive — per-booking fees eat into margins
- Legacy XML/EDIFACT protocols are painful to integrate
- Limited ancillary product merchandising
- No low-cost carrier coverage (Ryanair, Wizz Air, EasyJet absent)
- Content parity issues — airlines increasingly offer better fares on direct channels
The GDS isn't going away. But it's no longer the only game in town, and the airlines know it.
Tier 2: NDC — The Airline-Direct Revolution
New Distribution Capability (NDC) is an IATA standard that allows airlines to distribute their content directly to travel sellers through modern APIs, bypassing the GDS. Think of it as airlines taking control of their own distribution — setting their own fares, bundling ancillaries, and creating personalized offers.
By 2026, NDC has gained significant traction. Lufthansa Group famously introduced a GDS surcharge in 2015, pushing agents toward NDC. American Airlines, Singapore Airlines, and Qatar Airways have all invested heavily in NDC programs. The promise: richer content, lower distribution costs, and better customer experience.
Pros of NDC:
- Lower distribution costs for airlines (and potentially lower fares for customers)
- Rich media content — images, detailed seat maps, bundle descriptions
- Airlines can offer exclusive NDC-only fares
- Modern REST/JSON APIs (depending on the airline)
Cons of NDC:
- Fragmented — every airline's NDC implementation is different
- Not all airlines support NDC, and coverage varies wildly
- Servicing (changes, cancellations, refunds) is often incomplete
- Requires individual agreements with each airline
- Still doesn't cover LCCs — they have their own strategies
NDC is a step forward, but it creates a new problem: integration complexity. Connecting to 50 airlines via NDC means 50 different API implementations, 50 different servicing flows, and 50 different commercial agreements.
Tier 3: Direct / Human-Assisted — The LCC Layer
The third tier is the one most travel APIs ignore entirely. Low-cost carriers like Ryanair, Wizz Air, EasyJet, Spirit, and AirAsia don't participate in GDS or NDC. They sell directly — through their own websites and apps — and they have no plans to change.
For travel platforms, this creates a binary choice: either you skip LCCs entirely (and lose 40%+ of short-haul coverage), or you find another way to book them.
The "another way" has historically been screen scraping — automated bots that interact with airline websites to extract pricing and make bookings. But airlines aggressively combat scraping with CAPTCHAs, rate limiting, and legal action. It's an arms race that's expensive to maintain and unreliable at scale.
The more sustainable approach is human-assisted booking: trained operators who book directly on airline websites on behalf of the customer. This sounds old-fashioned, but when combined with modern API orchestration, it becomes a powerful hybrid model.
How RunRelay Combines All Three Tiers
RunRelay is built from the ground up to be a unified distribution layer that combines GDS, NDC, and direct/human-assisted booking into a single API.
| Feature | GDS | NDC | Direct (RunRelay) |
|---|---|---|---|
| Full-service carriers | ✓ | ✓ | — |
| Low-cost carriers | ✗ | ✗ | ✓ |
| Ancillary products | Limited | Good | Full |
| Booking speed | Instant | Instant | 5-15 min (async) |
| Post-booking changes | Via GDS | Via airline | Via concierge |
When an API consumer sends a search request, RunRelay:
- Queries GDS for full-service carrier availability and pricing
- Queries NDC connections for airline-direct fares and bundles
- Returns LCC results from direct airline data sources
- Normalizes everything into a single, consistent response format
The API consumer doesn't need to know — or care — which distribution channel serves each result. A Lufthansa flight via NDC and a Ryanair flight via human-assisted booking look identical in the API response. The booking flow is the same. The webhook confirmations are the same.
The Future of Distribution
The travel industry's distribution problem isn't going to be solved by any single standard. GDS will remain relevant for complex itineraries and corporate travel. NDC will continue to grow as airlines invest in direct distribution. And LCCs will continue to resist intermediaries.
The winners in this landscape won't be the platforms that bet on one channel. They'll be the ones that abstract away the complexity and give their customers a single, complete view of the market.
That's exactly what RunRelay does. One API. Three distribution tiers. Complete coverage.