The Standard
An operating contract for systems that need to work together.
HOS is a shared set of rules that lets a PMS, a housekeeping tool, a messaging platform and, later, AI tools describe the same situation in the same way. It works alongside existing standards and builds on their strengths. It does not replace your PMS, require a cloud or tell any vendor how to build its product.
Why HOS
What hotel systems lack: a shared language.
Same meaning everywhere
A room status, a booking change or a finished cleaning task means the same thing in every system, not just inside one integration.
Always traceable
Every piece of information says which system it came from, when it happened and whether that system is the official source. Nothing is quietly merged.
One step at a time
The same foundation that spots problems today will later support actions, always with your team's approval, and gives AI no freedom it has not earned.
HOS, HTNG and OpenTravel
They carry the messages. HOS makes the facts trustworthy.
What each standard answers, where HOS adds to them, and where it is still behind.
How it works
Four building blocks.
In brief: a shared vocabulary, a standard format for updates, a statement of what each system provides, and rules for future actions. Each block gives its name in the specification, for technical teams.
Core
A shared vocabulary for the hotel group, the property, its rooms and their maintenance, bookings, stays, tasks, guests (never by name) and messages. In the specification: Tenant, Property, Unit, Maintenance window, Reservation, Stay, Task, Guest and Message.
Events
Every change travels as a standard update that says where it comes from, the hotel's local date and time zone, what caused it and which version of HOS it follows. In the specification: CloudEvents-compatible events.
Capabilities
Each system publishes what it can send, what it is the official source for, and how long it keeps and can replay its updates. In the specification: the Event Producer manifest.
Trust
Future actions will be refused unless allowed, limited to one organisation's data, checked against the hotel's rules, approved and recorded. In the specification: default-deny, tenant-scoped, auditable policies.
{
"specversion": "1.0",
"id": "hk-002231",
"source": "urn:hos:housekeeping:demo",
"type": "unit.status_changed",
"time": "2026-07-30T06:40:00Z",
"datacontenttype": "application/json",
"hosschemaversion": "0.1",
"hosrecordedat": "2026-07-30T06:40:02Z",
"hostenant": "tenant_demo",
"hosproperty": "prop_demo",
"hospropertytimezone": "Europe/Paris",
"hosbusinessdate": "2026-07-30",
"hossubjects": "unit:unit_204",
"data": {
"unit_id": "unit_204",
"dimension": "housekeeping",
"previous": "inspected",
"current": "dirty",
"authority_source": "urn:hos:housekeeping:demo",
"reason": "departure"
}
}Inspect the contract
Technical detail is available when you need it.
Trajectory
HOS starts by observing; it earns the right to do more.
- Closed
Observe
Spot problems: shared updates with clear sources, and alerts such as a room not ready for an arrival. Proven on demo hotels; a pilot hotel is wanted.
- Now
Act
Act within the hotel's rules: assign a room, move a cleaning task up the list, message a guest.
- Later
Trust
Written, versioned rules, approvals, a record of every action and clear limits on what each tool may do.
- Later
Agents
AI agents that state what they do and offer the same guarantees in every hotel.
- Later
Ecosystem
Certified connectors and a voluntary community of systems that work together.