Glossary

Adapter

The code that turns what a hotel system knows, such as a PMS's webhooks, into HOS facts. It makes the system a producer, without changing the system itself.

Used in: Build an adapter

Authority

The system of record for a value, such as the housekeeping app for a unit's cleaning status. Only the authority changes that value; facts from other systems are recorded and shown as conflicts, never merged into it.

Used in: Concepts, Validate files, Sign and publish, Build an adapter

Business date

The hotel's operating day a fact belongs to, in its own time zone. It can differ from the calendar date of the fact's time: a night audit after midnight still belongs to the day before.

CloudEvents

An open format for describing events, which HOS events follow: a few standard attributes, such as source, id, type and time, around the event's data. HOS adds its own attributes, which start with hos.

Conformance scenario

A made-up sequence of deliveries, with the manifests of its producers and the expected outcome. A system replays it and compares its results with the expected ones.

Used in: Concepts, Quickstart, Read a report, Test a consumer

Consumer

A system that receives HOS facts and decides what to do with each one.

Used in: Overview, Concepts, Read a report, Test a consumer, Check a producer

Crosswalk

The table an adapter keeps between the ids of a source system and the HOS ids it gave them, such as room 204 and unit_204. It must survive restarts: without it, the same room would get a new HOS id.

Used in: Build an adapter

Delivery

One arrival of a fact at a consumer. Because delivery is at least once, the same fact can have several deliveries; a consumer keeps the first and discards the others as duplicates.

Disposition

What a consumer does with a fact it receives: applied, or set aside as a duplicate, superseded by a later fact, non_authoritative when its producer is not the authority, or undeclared_capability when its producer did not declare it.

Used in: Overview, Concepts, Quickstart, Replay a stream, Test a consumer

Exit code

The number a command returns when it ends, which scripts and CI read. hos returns 0 when everything is valid or passed, 1 when a file is invalid or a check failed, and 2 when the command is wrong or a file could not be read.

Used in: Concepts, Quickstart, Validate files

Fact (event)

One thing that happened in a hotel system, such as a unit becoming clean, sent as a CloudEvent in the HOS format. It states what the source knows; it does not ask anyone to do anything.

Used in: Concepts, Quickstart

JUnit report

An XML file of test results that most CI tools can display. hos conformance run writes one with --junit: one test suite per scenario, one test case per delivery.

Used in: Use in CI

JWKS

JSON Web Key Set: the public keys of a producer, published next to its manifest. Consumers use them to check the manifest's signature. The private key that signs stays with the producer.

Used in: Concepts, Sign and publish

Key id (kid)

The name of a key in a key set. A signature names the key that made it by its kid, so a consumer finds the right public key. hos uses the key's fingerprint by default.

Manifest

A producer's declaration: the facts it publishes and for which properties, the values it is the authority for, how it delivers, replays and keeps them, and its known limitations. The producer signs it.

Used in: Overview, Concepts, Quickstart, Read a report, Validate files, Check a producer, Sign and publish, Build an adapter

Normative and reference levels

The two levels of a conformance run. Normative compares the dispositions, which the HOS Events rules decide: every conformant consumer reaches them. Reference also compares arrival readiness and situations with the reference projection, which is not normative.

PMS

Property management system: the hotel's main software for reservations, stays, rooms and billing, such as Mews, Apaleo or Cloudbeds.

Used in: Concepts

Private key

The secret half of a signing key. Whoever holds it can sign as the producer, so it is never published or committed, and is replaced at once if it leaks.

Producer

A system that publishes HOS facts, such as a property management system (PMS) or a housekeeping app. Its manifest says what it publishes.

Used in: Overview, Concepts, Quickstart, Read a report, Check a producer, Build an adapter

Property

A hotel, in HOS terms: the operating context of a fact, with its own time zone and business date. A property belongs to one tenant.

Redelivery

What a producer publishes again from the same source data, for example after a restart. It must bring back the same facts, with the same ids and content, so that consumers discard them as duplicates.

Used in: Check a producer

Reference projection

The way the SDK reads arrival readiness from the facts, to show what HOS makes possible. It is not normative: a consumer can assess arrivals differently and still follow HOS Events 0.1.

Used in: Concepts, Replay a stream, Test a consumer

Signature

manifest.jws, made with the producer's private key. It proves who declared the manifest and that nobody changed it since. It expires, 90 days after signing by default with hos, so the producer signs again before then.

Used in: Concepts, Sign and publish

Situation

An alert a consumer raises from the facts, such as an arrival at risk because its room is not ready. HOS defines two reference situations, raised and resolved, as an example of what the facts make possible.

Snapshot

An event that restates a whole state, such as every status of a unit, rather than one change. It is marked as a snapshot, classified for sensitivity, and declared in the producer's manifest; it serves to recover a state that changes could not.

Used in: Rules

Source

The attribute of a fact that names the producer that published it, such as urn:hos:pms:demo. With the fact's id, it identifies the fact.

Stream (JSON Lines)

A file of facts, one JSON object per line, usually named .jsonl, in the order they were delivered.

Used in: Concepts, Validate files

Tenant

The organisation the data belongs to, such as a hotel group, and the boundary of its security and policies. Every property belongs to one tenant.

Used in: Rules

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