API Events

No Kafka. @platformatic/kafka is declared in package.json but there is no producer/consumer wiring in src/. All eventing is in-process (eventemitter3 EventBus) fanning out to BullMQ queues, with real-time fan-out over WebSocket. See ADR-0001.

1. Inbound — Kafka

None. The service consumes no Kafka topics.

2. Outbound — Kafka

None. The service produces no Kafka topics.

3. In-process Events (EventBus)

EventBus (eventemitter3) — emitted by TicketEmitter, handled by listeners in src/application/events/listeners/. Event types are TicketEventTypes (dotted strings) from @nx/core. Synchronous within the API process; listener failures are caught and logged (never crash the emitter).

Event type	Emitter method	Listener(s)	Side effects
ticket.created	TicketEmitter.ticketCreated	TicketCreatedListener	Increment category/tag counts; enqueue context-enrichment + assignment jobs
ticket.status_changed	TicketEmitter.ticketChangedStatus	TicketStatusChangedListener	Status side effects (notifications, survey trigger)
ticket.assigned	TicketEmitter.ticketAssigned	TicketAssignedListener	Assignment notifications
ticket.message.created	TicketEmitter.ticketMessageCreated	TicketMessageCreatedListener	Reply notifications, SLA first-response marking

4. Inbound — BullMQ

Queues created by QueueComponent; consumed by workers in src/components/workers/ (worker process, RUN_MODE=worker). Concurrency from WORKER_CONFIG.

Queue	Job name(s)	Producer	Worker → Use-case	Concurrency	Retries
helpdesk.sla-monitor	sla-monitor	Cron (repeatable) + manual trigger	sla-monitor.worker → RunSlaMonitorUseCase	1	2, fixed 60s
helpdesk.escalation	escalation, escalation-batch	sla-monitor / escalation manager	escalation.worker → ProcessEscalationUseCase	5	3, exp 5s (priority 1)
helpdesk.assignment	assign	TicketCreatedListener	assignment.worker → AutoAssignTicketUseCase	5	3, exp 5s
helpdesk.notification	notification, notification-batch, notification-digest	many	notification.worker → ProcessNotificationService	10	5, exp 5s (priority 10)
helpdesk.context-enrichment	enrich	TicketCreatedListener	context-enrichment.worker → EnrichTicketContextUseCase	30	3, exp 5s
helpdesk.survey-trigger	survey-trigger	status-changed flow	survey-trigger.worker → TriggerSurveyUseCase	3	3, exp 10s

A helpdesk.analytics-update queue name (ANALYTICS_UPDATE) exists in QUEUE_NAME, but no worker/queue is wired for it. Failed jobs route to HandleDeadLetterUseCase via dlq.helper.ts.

5. Outbound — BullMQ

Jobs are enqueued via JobDispatcherHelper (publish / publishAll) and the typed job builders in src/shared/helpers/jobs/.

Job builder	Queue	Trigger
ContextEnrichmentJob.enrich	context-enrichment	Ticket created with context
AssignmentJob.assign	assignment	Ticket created (strategy LOAD_BALANCED)
NotificationJob.*	notification	SLA warnings/breaches, assignment, replies, escalation
EscalationJob.*	escalation	SLA breach by sla-monitor
SurveyTriggerJob.*	survey-trigger	Ticket resolved/closed
SLA monitor cron	sla-monitor	QueueComponent.scheduleSlaMonitoring() (jobId sla-monitor-cron)

6. WebSocket Emissions

Delivered by ApplicationWebSocketComponent + socket-event.service.ts. Topics/rooms built from @nx/core helpers.

Topic	Room	Trigger
HelpdeskWebSocketTopics.HELP_DESK (observation/helpdesk)	HelpdeskWebSocketRooms.getHelpdeskRooms({ ticketId, messageId }) (helpdesk/:ticketId/:messageId)	New message / status change / assignment / SLA event

7. Payload Schemas

In-process event payloads are TS interfaces in src/shared/common/interfaces/ (not centralized message contracts, since there is no Kafka). Representative shapes:

// ticket.created — ITicketCreatedEventData
interface ITicketCreatedEventData {
  ticketId: string;
  merchantId: string;
  categoryId: string;
  priority: TTicketPriorities;
  context?: Record<string, unknown>;
  categoryRouting?: unknown;
  metadata: { tagIds: string[]; [k: string]: unknown };
}

8. Idempotency & Ordering

Channel	Guarantee	Ordering	Recovery
EventBus	in-process, at-most-once	emit order, synchronous	none — listener errors logged, not retried
BullMQ jobs	at-least-once (retries per queue)	per-queue, no global order	retry w/ backoff → DLQ via HandleDeadLetterUseCase; worker idempotency helpers de-dupe
SLA cron	exactly-one schedule	n/a	fixed jobId: 'sla-monitor-cron' prevents duplicate repeatables

9. Related Pages

• Integration
• Architecture — Runtime Scenarios
• ADR-0001 — In-process EventBus + BullMQ