Duffel Flights and Stays API vs Expedia Group Rapid API

Duffel Flights and Stays API

Self-serve sign-up and test mode with no card or contract. No OpenAPI document, llms.txt or official MCP server.

Expedia Group Rapid API

Expedia's lodging inventory with shop, price check, book, change and cancel in one API. Partner application and site review before production, no self-serve keys.

Duffel Flights and Stays API

1. Send Duffel-Version: v2 on every request or you get a version error
2. Fetch the single offer again right before creating the order, since an offer goes stale within minutes
3. Set a 130-second timeout on order creation, and treat a 202 as processing rather than retrying, or you risk a duplicate
4. Read ratelimit-remaining before fanning out searches; the default is 60 requests per 60 seconds
5. Count offer requests. Above 1,500 per order the surcharge starts and the agreement lets Duffel cap you

Expedia Group Rapid API

1. Build the SHA-512 signature from key, secret and the current epoch seconds in that order, per request
2. Send Customer-Ip and the session headers the docs ask for, since fraud checks use them
3. Point everything at test.ean.com until the site review is through; the paths match api.ean.com
4. Follow the links in each response rather than building URLs; price check and book links carry tokens
5. Read the Rate-Limit-Minute-Remaining and Rate-Limit-Day-Remaining headers, since the docs publish no ceilings