Unified PMS API
One API. Every Property Management System.
Connect your product to 40+ vacation rental and hospitality PMS platforms through a single integration. Common data model, real-time webhooks, fully managed authentication — zero integration debt.
32+
PMS integrations
28,000+
properties connected
400+
developers on Calry
THE INFRASTRUCTURE LAYER
The Infrastructure Layer for Vacation Rental Tech
The Unified PMS API is the infrastructure layer behind OnSeason's own products — the same API that powers our AI Website Builder and Booking Engine. We've opened it up so any travel tech product can build on top of it through Calry, our developer platform.
One Connection
Connect once via API key and instantly access 40+ vacation rental PMS systems through a single, standardised interface.
Common Data Model
Normalised data across all PMSs — properties, availability, rates, reservations, and guest records all in one schema.
Real-Time Sync
Webhooks push live availability, rate, and booking updates. No polling. No stale data. No double bookings.
Managed Authentication
OAuth flows, token refresh, and credential management handled for you. Zero integration debt on the auth side.
Event-Driven Webhooks
Subscribe to the events you care about. Get notified instantly when bookings, availability, or rates change in any connected PMS.
Developer-First DX
Clean REST API, comprehensive documentation, SDKs, and sandbox environments — built the way developers expect.
Supported PMS Platforms
A growing list of integrations across short-term rental, vacation rental, and hospitality PMS systems.
40+ more integrations are available
See all integrationsWHO IT'S FOR
For Travel Tech Builders and Property Managers
SaaS builders
Stop spending 6 months on PMS integrations. Connect once, ship faster, and focus on what makes your product unique.
Property managers
Use the same API powering OnSeason to connect your existing tools, custom apps, or in-house dashboards to your PMS.
Tour operators & agencies
Access rental inventory programmatically for custom booking flows, itinerary builders, or white-label platforms.
// Connect once. Access everything.
GET
/v1/properties?pms=guesty
// Same endpoint for any PMS
GET
/v1/properties?pms=hostaway
// Real-time availability
GET
/v1/availability/:propertyId
Full docs at calry.app/docs
FAQ
Frequently Asked Questions
Build on the PMS Infrastructure OnSeason Runs On
Join 500+ developers using Calry to connect their products to the vacation rental ecosystem.