Medication Service — Event Schemas

Status: populated Owner: TBD Last updated: 2026-04-17 Companion: Service Template · Naming · 04 Event-driven

1. Envelope

All events use the platform EventEnvelope (CloudEvents v1.0). Subject pattern: medication.{aggregate}.{event}.v{N}.

2. Events Produced

Subject	v	Retention	Aggregate	Trigger
medication.prescription.drafted.v1	1	30d	Prescription	Draft created
medication.prescription.signed.v1	1	2y	Prescription	Sign success
medication.prescription.discontinued.v1	1	2y	Prescription	Discontinue
medication.prescription.held.v1	1	90d	Prescription	Hold
medication.prescription.resumed.v1	1	90d	Prescription	Resume
medication.alert.overridden.v1	1	7y	AlertOverride	Override recorded
medication.dispensing.completed.v1	1	7y	DispensingEvent	Dispense success
medication.dispensing.partial.v1	1	7y	DispensingEvent	Partial dispense
medication.dispensing.returned.v1	1	7y	DispensingEvent	Return
medication.controlled_substance.dispensed.v1	1	10y	DispensingEvent	Schedule II–V dispense
medication.administration.recorded.v1	1	2y	MAR	Admin event
medication.reconciliation.completed.v1	1	2y	ReconciliationSession	Session complete
medication.inventory.stock_received.v1	1	2y	StockItem	GRN
medication.inventory.reorder_alert.v1	1	90d	StockItem	Below reorder point
medication.inventory.expiry_alert.v1	1	90d	StockItem	Expiry horizon
medication.inventory.recall_triggered.v1	1	7y	StockItem	Lot recalled
medication.fulfillment.queued.v1	1	30d	Prescription	MR ingested from gateway

Example — medication.prescription.signed.v1

{
  "specversion": "1.0",
  "type": "medication.prescription.signed.v1",
  "source": "ghasi/medication-service",
  "id": "evt_01HX...",
  "time": "2026-04-17T09:12:31Z",
  "tenantid": "ten_...",
  "actorid": "usr_...",
  "correlationid": "corr_...",
  "data": {
    "prescriptionId": "rx_01HX...",
    "patientId": "pat_...",
    "medicationCode": "RxNorm|197361",
    "medicationDisplay": "Amoxicillin 500 MG Oral Capsule",
    "dose": { "amount": 500, "unit": "mg" },
    "route": "oral",
    "frequency": "TID",
    "durationDays": 7,
    "quantity": 21,
    "quantityUnit": "capsule",
    "refillsAuthorized": 0,
    "isControlled": false,
    "signedAt": "2026-04-17T09:12:30Z",
    "prescriberId": "usr_...",
    "overrides": []
  }
}

Example — medication.dispensing.completed.v1

{
  "type": "medication.dispensing.completed.v1",
  "data": {
    "dispenseId": "dsp_...",
    "prescriptionId": "rx_...",
    "patientId": "pat_...",
    "dispensedQuantity": 30,
    "quantityUnit": "tablet",
    "stockItemId": "stk_...",
    "lotNumber": "LOT-2026-04",
    "expiryDate": "2027-12-31",
    "pharmacistId": "usr_...",
    "counterSignId": null,
    "isPartial": false,
    "gatewayMedicationDispenseFhirId": "MedicationDispense/..."
  }
}

3. Events Consumed

Subject	Producer	Purpose
orders.medication_request.activated.v1	orders-service	Seed medication list on CPOE activation
eprescribing.medication_request.created.v1	ghasi-eprescribing-gateway-service	Inbound Rx from external prescriber
eprescribing.medication_request.updated.v1	ghasi-eprescribing-gateway-service	Updates to ingested Rx
patient-chart.allergy.updated.v1	patient-chart-service	Invalidate cached allergy checks
tenant.formulary.updated.v1	tenant-service	Reload formulary cache

4. Legacy Event Mapping

Legacy shorthand	Legacy subject	New subject
med.order.created	MEDICATION.medication.prescribed	medication.prescription.drafted.v1
med.order.signed	MEDICATION.medication.signed	medication.prescription.signed.v1
med.order.discontinued	MEDICATION.medication.discontinued	medication.prescription.discontinued.v1
med.alert.overridden	MEDICATION.alert.overridden	medication.alert.overridden.v1
PHARMACY.dispensing.completed	same	medication.dispensing.completed.v1
PHARMACY.inventory.*	same	medication.inventory.*.v1
PHARMACY.controlled-substance.dispensed	same	medication.controlled_substance.dispensed.v1

Dual-publish window: M2 — both subjects emitted; consumers migrate. Legacy subjects retired in M3.

5. Dead-Letter Handling

• Failed consumer deliveries (inbound gateway events) → DLQ medication.ingestion.dlq with 5-retry policy (exponential backoff, max 2h).
• Failed outbound publishes → outbox stays, OutboxRelay retries; oldest-event alert at 10min.