The Linked Commons Model

The spec

The Linked Commons Model.

LCM v0.1 — draftThe Linked Commons Model is the canonical data and event schema of the Serai Project — the shared language every certified connector normalizes to.

apaleo.jsonjson

{
  "specversion": "1.0",
  "type": "lcm.reservation.created",
  "source": "//serai/connector/apaleo/prop-001",
  "id": "0197f3c2-7d1e-7a4b-9c3d-2f8a1b6e4d90",
  "time": "2026-07-12T14:03:21Z",
  "lcmprovenance": "apaleo",
  "data": {
    "snapshot": {
      "reservationId": "0197f3c2-11aa-7bb2-8c01-55d2e9a04f18",
      "status": "confirmed",
      "arrival": "2026-08-01",
      "departure": "2026-08-04",
      "total": {
        "amount": 74250,
        "currency": "EUR"
      }
    }
  }
}

stayntouch.jsonjson

{
  "specversion": "1.0",
  "type": "lcm.reservation.created",
  "source": "//serai/connector/stayntouch/prop-014",
  "id": "0197f3c2-89aa-7c3e-9d21-4f0b6c2e7a11",
  "time": "2026-07-12T14:03:21Z",
  "lcmprovenance": "stayntouch",
  "data": {
    "snapshot": {
      "reservationId": "0197f3c2-11aa-7bb2-8c01-55d2e9a04f18",
      "status": "confirmed",
      "arrival": "2026-08-01",
      "departure": "2026-08-04",
      "total": {
        "amount": 74250,
        "currency": "EUR"
      }
    }
  }
}

Illustrative sample — two connectors, one identical event shape.

The event envelope

A full event, end to end.

reservation.created.jsonjson

{
  "specversion": "1.0",
  "type": "lcm.reservation.created",
  "source": "//serai/connector/pms01/prop-001",
  "id": "0197f3c2-7d1e-7a4b-9c3d-2f8a1b6e4d90",
  "time": "2026-07-12T14:03:21Z",
  "datacontenttype": "application/json",
  "lcmprovenance": "pms01",
  "lcmsequence": 4021,
  "lcmbusinessdate": "2026-07-12",
  "data": {
    "snapshot": {
      "reservationId": "0197f3c2-11aa-7bb2-8c01-55d2e9a04f18",
      "externalIds": [
        {
          "system": "pms02",
          "idType": "reservationId",
          "value": "BER-4471"
        }
      ],
      "status": "confirmed",
      "arrival": "2026-08-01",
      "departure": "2026-08-04",
      "total": {
        "amount": 742.5,
        "currency": "EUR"
      }
    },
    "delta": {
      "status": {
        "from": null,
        "to": "confirmed"
      }
    }
  }
}

Illustrative sample payload.

Design posture

Event-first. Additive-only. The largest possible superset.

The model aims to be the largest possible superset — translators map per system, and unsupported operations return "not implemented". Updates are strictly additive: fields are added, never removed, and connectors pick up model updates automatically. The versioned spec, the connector engine, and the connectors are to be released under Apache-2.0 at the published gate.

The doc set