# Chapter 4 - Data Exchange Actions

These actions define how clients and servers exchange hotel data. For every data exchange request both `action` and `request` parameters are mandatory, and the XML payloads must validate against OTA2015A plus the stricter AlpineBits schema.

## Action Summary

| Known as (since) | Usage | Action parameter | Request XML | Response XML |
| --- | --- | --- | --- | --- |
| FreeRooms (2011-11) | Client sends room availability notifications | `OTA_HotelInvCountNotif:FreeRooms` | `OTA_HotelInvCountNotifRQ` | `OTA_HotelInvCountNotifRS` |
| GuestRequests (2012-05) | Client asks server for quote/booking requests | `OTA_Read:GuestRequests` | `OTA_ReadRQ` | `OTA_ResRetrieveRS` |
| GuestRequests Push (2018-10) | Client pushes quote/booking requests to server | `OTA_HotelResNotif:GuestRequests` | `OTA_HotelResNotifRQ` | `OTA_HotelResNotifRS` |
| GuestRequests Status Update Push (2022-10) | Client sends status updates for quote/booking requests | `OTA_HotelResNotif:GuestRequests_StatusUpdate` | `OTA_HotelResNotifRQ` | `OTA_HotelResNotifRS` |
| GuestRequests Acknowledgments (2014-04) | Client acknowledges requests it received | `OTA_NotifReport:GuestRequests` | `OTA_NotifReportRQ` | `OTA_NotifReportRS` |
| Inventory/Basic Push (2015-07) | Client sends room category info and room lists | `OTA_HotelDescriptiveContentNotif:Inventory` | `OTA_HotelDescriptiveContentNotifRQ` | `OTA_HotelDescriptiveContentNotifRS` |
| Inventory/Basic Pull (2017-10) | Client requests room category info and room lists | `OTA_HotelDescriptiveInfo:Inventory` | `OTA_HotelDescriptiveInfoRQ` | `OTA_HotelDescriptiveInfoRS` |
| Inventory/HotelInfo Push (2015-07) | Client sends additional property descriptive content | `OTA_HotelDescriptiveContentNotif:Info` | `OTA_HotelDescriptiveContentNotifRQ` | `OTA_HotelDescriptiveContentNotifRS` |
| Inventory/HotelInfo Pull (2017-10) | Client requests additional property descriptive content | `OTA_HotelDescriptiveInfo:Info` | `OTA_HotelDescriptiveInfoRQ` | `OTA_HotelDescriptiveInfoRS` |
| RatePlans (2014-04) | Client sends rate plans with prices and booking rules | `OTA_HotelRatePlanNotif:RatePlans` | `OTA_HotelRatePlanNotifRQ` | `OTA_HotelRatePlanNotifRS` |
| BaseRates (2017-10) | Client requests rate plan information | `OTA_HotelRatePlan:BaseRates` | `OTA_HotelRatePlanRQ` | `OTA_HotelRatePlanRS` |
| Activities (2020-10) | Client requests hotel activity information | `OTA_HotelPostEventNotif:EventReports` | `OTA_HotelPostEventNotifRQ` | `OTA_HotelPostEventNotifRS` |

## Encoding and Schema Requirements

- All XML documents must be UTF-8 encoded. Expect arbitrary Unicode (including emojis or non-Latin characters); validate and sanitize before storage to avoid visualization or data corruption issues.
- Requests and responses must validate against OTA2015A. The AlpineBits schema provided in the documentation kit is stricter: every document that passes AlpineBits validation also passes OTA2015A, not vice versa.
- Sample XML files and the stricter XSD are included in the AlpineBits documentation kit for each protocol version.
- Currency codes follow ISO 4217 (EUR shown in samples but any ISO code is allowed). If a server receives an unsupported currency it must reply with a warning outcome; a client should discard responses using unsupported currencies.

## Copyright and Licensing of Multimedia Content

- Many messages carry URLs to multimedia objects. Since XML has no place for license data, AlpineBits recommends embedding licensing metadata (e.g., IPTC/EXIF for images) in the files themselves and preserving it in derived works.
- Alternatively (or additionally), include HTTP headers `X-AlpineBits-License` and `X-AlpineBits-CopyrightHolder` when serving multimedia content. Receivers should honor and propagate these headers to derived assets.