July 20, 2026 · Alper Tekin
How to evaluate a travel API before you integrate
A practical checklist for agencies and OTAs comparing travel APIs: authentication, idempotency, errors, settlement and content quality.
Most travel API evaluations start with inventory and end with price. Both matter, but neither is what hurts six months after go-live. What hurts is operational behaviour: how the API fails, how money moves and how much of your roadmap each new vertical costs.
Here is the checklist we recommend, in the order the pain usually arrives.
The evaluation table
| Criterion | What to ask | Red flag |
|---|---|---|
| Authentication | Are requests signed, or is it a static bearer token? | A token that replays anywhere |
| Idempotency | Can a booking retry safely after a timeout? | "Just do not retry" |
| Error contract | Are error codes stable, documented and machine-readable? | HTML error pages, blank 500s |
| Settlement | One balance across products, or per-supplier invoicing? | A folder of monthly PDFs |
| Currencies | Can you price and settle in your own currency? | Quotes in one fixed currency |
| Content quality | Are itineraries and policies structured fields? | Cancellation rules in prose |
| Coverage growth | Does a new vertical mean a new contract? | Procurement restarting per product |
Why idempotency belongs near the top
A booking API without idempotency keys turns every network incident into a customer service incident. If a timeout can create a hidden duplicate booking, you will pay for that design decision during your busiest week of the year, which is exactly when timeouts happen.
Test failure before you test success
Ask for the error catalogue before the sales deck. Trigger an expired quote, an insufficient balance and a sold-out session in sandbox. An API that fails predictably is an API you can operate.
The traveldistro platform pages document how we approach each row of this table, and the error catalogue is public.