What OpenTravel Alliance means
Before common standards, every hotel chain, car rental firm and booking site needed a custom format for each partner. OpenTravel was set up in 1999 to agree shared message structures so that, for example, a hotel availability request looks broadly the same whichever system sends it. Membership spans airlines, hotels, car rental, cruise, rail, tour operators, travel agencies and technology companies.
The best-known output is the XML message set, released in numbered versions such as 2008B. Messages come in request and response pairs and carry names such as OTA_AirFareDisplayRS. OpenTravel says there is no cost to download or implement them, which helped them spread into hotel channel managers, car rental systems and many travel APIs.
The "OTA" prefix causes confusion. In message names it refers to the OpenTravel Alliance, not an online travel agency.
From the mid-2010s OpenTravel worked on a "2.0" object model. It groups reusable objects into libraries and can be exchanged as JSON or XML over REST, with lighter payloads aimed at mobile and web developers. A 2018A hospitality publication, for example, shipped JSON and XML messaging with Swagger files.
In October 2024 OpenTravel announced a reboot. It said funding had become too low to sustain its work, and that a September 2024 meeting of industry leaders had agreed to focus on consistent JSON and REST APIs and on offer and order behaviour, possibly within a larger open-source community. Membership and funding models had not been settled at that point.
How OpenTravel Alliance works
Implementers use the published schemas as a shared contract, then agree the details that each partnership needs.
- Download the specificationA developer downloads the XML schemas or 2.0 model files and code lists from OpenTravel at no charge.
- Pick the message pairsThe partners choose the request and response messages they need, such as hotel availability, reservation or air fare display.
- Agree a profileBecause the schemas have many optional fields, partners agree which elements are mandatory, which codes are used and how errors are returned.
- Build and validateEach side builds its interface and validates messages against the schema files to catch structural errors before testing.
- Certify and go liveThe partners run end-to-end tests on real scenarios, then switch production traffic to the new connection.
OpenTravel Alliance in practice
Verified. In OpenTravel's 2008B schema set, the air fare display response OTA_AirFareDisplayRS includes a PassengerTypeCode attribute documented with examples such as ADT, CHD and INF, the same passenger type codes used in GDS pricing.
Verified. OpenTravel's 2018A 2.0 publication for hospitality covered hotel search, availability, offers, orders and reservations, and was delivered with XML and JSON messaging, WSDLs, Swagger definitions and examples.
Illustrative. A bedbank and a hotel channel manager both support OpenTravel hotel messages. They still spend time agreeing room and rate code mappings and which optional fields each will send, because the schema allows more than one way to express the same thing.
Who uses it
Advantages and limitations
Advantages
- Free to download and implement, which lowers the cost of building a new connection.
- A shared vocabulary across air, hotel, car, rail and cruise reduces the effort of mapping data between partners.
- Wide historical use means many developers and vendors already know the message structures.
- Versioned releases give partners a fixed reference point to agree on.
Limitations
- Many optional elements mean two OpenTravel-compliant systems can still be incompatible without a detailed agreed profile.
- XML messages are verbose compared with modern JSON APIs.
- OpenTravel's own 2024 reboot announcement described funding as too low to sustain its existing work, so future releases are uncertain.
- Airline distribution has largely moved towards IATA's NDC standard rather than OpenTravel air messages.
Frequently asked questions about OpenTravel Alliance
What does OTA mean in OTA_HotelAvailRQ-style message names?
In message names, OTA stands for the OpenTravel Alliance, the body that publishes the schemas. It has nothing to do with online travel agencies, even though both use the same three letters. RQ marks a request and RS marks the matching response.
Are OpenTravel specifications free to use?
Yes. OpenTravel states that there is no cost to download or implement its messaging specifications. Membership, which has dues on a sliding scale by company size, is needed only to take part in shaping the standards, not to use them in a product.
What is the OpenTravel 2.0 object model?
It is OpenTravel's newer, object-oriented way of defining travel data. Reusable objects are grouped into libraries and can be sent as JSON or XML, usually over REST. The aim was lighter messages and more flexibility for web and mobile developers than the original XML message set.
Is OpenTravel still active?
In October 2024 OpenTravel said it was rebooting because funding was too low to continue its existing work. The stated new focus is consistent JSON and REST APIs and shared offer and order behaviour, possibly within a larger open-source community. Check its website for the current status before relying on new releases.
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