# Viator

> Viator is a Tripadvisor company and the largest online marketplace for tours, activities and travel experiences, listing more than 300,000 bookable products across roughly 2,500 destinations. It sits on the demand side of travel distribution as an aggregator and reseller of third-party operator inventory, and on the supply side as the channel counterparty that tour operators' reservation systems connect into. Its developer surface is unusually open for travel: four complete OpenAPI documents and four Postman collections are downloadable without a login, and Basic Access affiliate keys are issued self-serve at no cost.

Generated by API Evangelist on 2026-07-28. Viator does not publish an llms.txt of its own — /llms.txt returns 403 on docs.viator.com and 404 on partnerresources.viator.com — so this file is generated from apis.yml and the artifacts in this repository.

Key facts an agent should know before calling anything:

- Authentication is a single organisation-wide API key sent in the `exp-api-key` header. There is no OAuth, no scopes and no per-user delegation, so every call carries the full authority of the partner account.
- `Accept: application/json;version=2.0` is mandatory on every Partner API v2 request. Omitting it returns HTTP 400 `INVALID_HEADER_VALUE`.
- Endpoint access is gated by partner tier (Basic-access Affiliate, Full-access Affiliate, Full-access + Booking Affiliate, Merchant), not by scope. An out-of-tier call returns 403.
- `partnerBookingRef` is the idempotency key for booking creation. Retry with the same value; Viator enforces its uniqueness so a duplicate booking cannot be created.
- All testing must happen on `https://api.sandbox.viator.com/partner`. Production is for live bookings only.
- Product reviews and everything inside `viatorUniqueContent` are licensed content that must not be exposed where a search engine can index it.
- No open travel standard (OpenTravel/OTA, HTNG, NDC, IATA) is referenced anywhere in any Viator specification.

## APIs

- [Viator Partner API v2](https://docs.viator.com/partner-api/technical/): The current demand-side contract — products, availability, bookings, payments, attractions and auxiliary reference data. OpenAPI 3.0.2, 33 operations, licensed CC BY 4.0. Base URL `https://api.viator.com/partner`.
- [Viator Reservation System API](https://docs.viator.com/supplier-api/technical/): The supplier-side connectivity contract, formerly the Supplier API. Inverted — it defines the endpoints a tour operator's reservation system must itself implement for Viator to call. OpenAPI 3.0.0, 15 operations, with published uptime, latency and error-rate SLAs and Viator-operated circuit breakers.
- [Viator Merchant API v1](https://docs.viator.com/partner-api/merchant/technical/): Legacy v1 merchant contract, superseded by the Partner API v2 but still published. OpenAPI 3.0.1, 28 operations.
- [Viator Affiliate API v1](https://docs.viator.com/partner-api/affiliate/technical/): Legacy v1 non-transactional affiliate contract, superseded by the Partner API v2. OpenAPI 3.0.2, 20 operations.

## Specs

- [Partner API v2 OpenAPI](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/openapi/viator-partner-api-v2-openapi.json): Recovered verbatim from Viator's Redoc-rendered documentation.
- [Reservation System API OpenAPI](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/openapi/viator-reservation-system-api-openapi.json)
- [Merchant API v1 OpenAPI](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/openapi/viator-merchant-api-v1-openapi.json)
- [Affiliate API v1 OpenAPI](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/openapi/viator-affiliate-api-v1-openapi.json)

## Collections

- [Basic-access Affiliate Postman collection](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/collections/Viator-Basic-Access-Affiliate-API-v2.postman_collection.json)
- [Full-access Affiliate Postman collection](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/collections/Viator-Affiliate-API-v2.postman_collection.json)
- [Full-access + Booking Affiliate Postman collection](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/collections/Viator-Affiliate-Booking-API-v2.postman_collection.json)
- [Merchant Postman collection](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/collections/Viator-Merchant-API-v2.postman_collection.json)

## Operating rules

- [API conventions](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/conventions/viator-conventions.yml): Authentication, versioning, idempotency, pagination, localisation, compression, tracing, error envelope, rate-limit signalling and the endpoint access tiers.
- [Error catalogue](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/errors/viator-problem-types.yml): The `{code, message, timestamp, trackingId}` envelope, every documented status, and the booking rejection-reason vocabulary.
- [Authentication profile](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/authentication/viator-authentication.yml)
- [Lifecycle, deprecation and SLAs](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/lifecycle/viator-lifecycle.yml): 12-month minimum deprecation notice, the breaking-change criteria, and the supplier-side SLA and circuit-breaker thresholds.
- [Sandbox and test data](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/sandbox/viator-sandbox.yml): The sandbox host, the `exp-demo` behaviour switch, and every test value Viator publishes.
- [Changelog](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/changelog/viator-changelog.yml)
- [Event surfaces](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/asyncapi/viator-events.yml): The booking event pull feed, Viator's hosted notification webhooks, and the inverted supplier callback contract.
- [Data model](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/data-model/viator-data-model.yml)
- [Conformance](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/conformance/viator-conformance.yml)

## Agent skills

- [Ingest and maintain the product catalogue](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/skills/viator-ingest-product-catalogue.md)
- [Search, check availability and complete a booking](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/skills/viator-search-and-book.md)
- [Book a multi-item cart and tokenise payment](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/skills/viator-cart-booking-and-payment.md)
- [Amend, cancel and reconcile bookings](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/skills/viator-amend-cancel-and-reconcile.md)
- [Implement reservation-system connectivity](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/skills/viator-reservation-system-connectivity.md)
- [Candidate MCP tool surface](https://raw.githubusercontent.com/api-evangelist/viator/refs/heads/main/mcp/viator-mcp.yml): Derived from the OpenAPI; Viator operates no MCP server of its own.

## Docs

- [Partner Resource Center](https://partnerresources.viator.com/)
- [Levels of API access](https://partnerresources.viator.com/travel-commerce/levels-of-access/)
- [Affiliate API solution](https://partnerresources.viator.com/travel-commerce/affiliate/)
- [Basic Access golden path](https://partnerresources.viator.com/travel-commerce/affiliate/basic-access/golden-path/)
- [Merchant API solution](https://partnerresources.viator.com/travel-commerce/merchant/)
- [Merchant API certification](https://partnerresources.viator.com/travel-commerce/merchant/certification/)
- [Implementation guides](https://partnerresources.viator.com/travel-commerce/implementation/)
- [Technical guide](https://partnerresources.viator.com/travel-commerce/technical-guide/)
- [Supplier API overview](https://docs.viator.com/supplier-api/technical/api-overview/)
- [Supplier connectivity overview](https://docs.viator.com/supplier-api/technical/connectivity-overview/index.html)
- [Partner Help Center](https://partnerhelp.viator.com/en)
- [Partner blog](https://partnerresources.viator.com/blog/)

## Optional

- [Viator Widgets](https://partnerresources.viator.com/travel-content/widgets/): No-code embeddable experience showcase, up to 30 products.
- [Viator Selector](https://selector.viator.com/): Hosted tool for finding experiences and generating affiliate links.
- [Affiliate links](https://partnerresources.viator.com/travel-content/links/) and [banners](https://partnerresources.viator.com/travel-content/banners/): 8% commission, 30-day cookie window.
- [Sign up](https://partners.viator.com/signup?mcid=66150&program=affiliate): Creating an affiliate account grants Basic Access immediately, at no cost.

## Contacts

- Partner API onboarding and support: affiliateapi@tripadvisor.com
- Partner API technical support: apitechsupport@viator.com
- Supplier / reservation system integrations: supplierAPI@viator.com