Answer
What is a hotel PMS integration and how does it work?
A hotel PMS integration is a connection, almost always through the PMS's API, that lets another system (a channel manager, booking engine, payment provider, accounting tool, or guest-experience app) read and write reservation, rate, and folio data automatically instead of staff retyping it. With API-first platforms such as Mews, Apaleo, and Oracle OPERA Cloud, the practical question is no longer whether integration is possible, but which fields each connector reads, whether it writes back, and how it behaves when the sync fails.
The main types of hotel PMS integration
Most properties end up connecting five or six categories to the PMS: a channel manager (syncs availability, rates, and inventory to the OTAs), a booking engine (writes direct reservations into the PMS), a payment provider (captures cards and reconciles to the folio), an accounting or revenue-management tool (pulls revenue and occupancy data), and an increasingly common guest-experience or guest-journey app (reads the reservation to power check-in, messaging, and in-stay services). Each one is a separate integration with its own data scope, so "it integrates with my PMS" rarely means all of them at once.
How a modern PMS integration actually connects
Modern integrations run over a REST API, usually with OAuth authentication and webhooks that push events (new booking, modification, check-in, checkout) in near real time instead of polling. The depth varies by platform. Mews exposes an Open API covering reservations, customers, rates, spaces, orders, and accounting, with more than 1,000 pre-built connectors in its Marketplace. Apaleo is built API-first, so every function is reachable through its Booking, Finance, and Payment APIs, with 200+ apps in the Apaleo Store. Oracle Hospitality Integration Platform (OHIP) exposes more than 3,000 APIs for OPERA Cloud, included in the Property Management Foundation, with transaction-based pricing from about USD 10 per 10,000 REST calls.
One-way vs two-way, and where a guest-experience layer fits
The most important distinction is one-way versus two-way sync. A channel manager and a booking engine usually write back into the PMS; a guest-experience layer typically reads reservations one way and posts charges to the folio without rewriting reservations. Guest-journey tools such as Duve, Canary, and Guestivo sit on top of the PMS rather than replacing it. Guestivo, for example, ingests reservations and posts folio charges through a provider-neutral layer whose only live PMS connector today is Apaleo; it is a guest-experience platform, not a PMS itself.
What to verify before you trust a PMS integration
The common failure pattern is trusting a vendor's "integrates with everything" claim, then discovering at go-live that your exact PMS is on a roadmap, the connector is one-way when you needed two-way, or a failed webhook silently drops a booking. The working pattern is to verify four things in writing: that your specific PMS is supported today (not planned), whether the sync is one-way or two-way, which exact fields move, and what happens when the connection fails. Ask to see the vendor's marketplace listing or certification for your PMS, not a generic wall of logos.