Kafka Events

22 event topics (11 producer + 11 consumer) across the notification delivery pipeline.

Event Format: CloudEvents 1.0

All events follow the CloudEvents 1.0 specification. Events are partitioned by tenant_id and published to Amazon MSK Serverless. Idempotency enforced via Redis with 24h TTL.

Brokers

Environment	Broker
Staging	`b-1.eventzr-msk.ap-south-1.amazonaws.com:9098`
Production	`b-1.eventzr-msk-prod.ap-south-1.amazonaws.com:9098`

CloudEvents Envelope

CloudEvents 1.0 envelopejson

{
  "specversion": "1.0",
  "type": "eventzr.notify.sent.v1",
  "source": "eventzr.notify-svc",
  "id": "evt-550e8400-e29b-41d4-a716-446655440000",
  "time": "2026-02-24T12:00:00.000Z",
  "datacontenttype": "application/json",
  "subject": "tenant-uuid",
  "data": {
    "tenantId": "tenant-uuid",
    "notificationId": "notif-uuid",
    "channel": "email",
    "userId": "user-uuid",
    "templateId": "template-uuid",
    "priority": "high"
  }
}

Producer Topics (11)

Events published by notify-svc when notification state changes occur. Downstream consumers: analytics-svc, wallet-svc, inbox-svc, audit-svc, crm-svc, amplify-svc, search-svc.

Delivery Lifecycle7

Topic	Description
`eventzr.notify.sent.v1`	Notification sent to CPaaS provider
`eventzr.notify.delivered.v1`	Delivery confirmed by provider
`eventzr.notify.failed.v1`	All retries exhausted
`eventzr.notify.bounced.v1`	Hard/soft bounce from provider
`eventzr.notify.read.v1`	Recipient opened notification
`eventzr.notify.cost_incurred.v1`	CPaaS cost recorded
`eventzr.notify.suppressed.v1`	Notification suppressed (opt-out, bounce, suppression list)

Template Lifecycle3

Topic	Description
`eventzr.notify.template.created.v1`	Template created
`eventzr.notify.template.updated.v1`	Template updated
`eventzr.notify.template.deleted.v1`	Template soft-deleted

Preference Changes1

Topic	Description
`eventzr.notify.preference.updated.v1`	User preferences changed

Consumer Topics (11)

Events consumed from 6 upstream services to trigger notifications.

auth-svcGroup: notify-svc-auth-consumer

Topic	Description	SLA
`eventzr.auth.otp.requested.v1`	Send OTP via preferred channel	10s (CRITICAL)

booking-svcGroup: notify-svc-booking-consumer

Topic	Description	SLA
`eventzr.booking.confirmed.v1`	Send booking confirmation	1min (HIGH)
`eventzr.booking.checkin_time.v1`	Send check-in reminder (T-24h)	1min (HIGH)

event-svcGroup: notify-svc-event-consumer

Topic	Description	SLA
`eventzr.events.published.v1`	Notify followers about new event	5min (NORMAL)
`eventzr.events.updated.v1`	Notify ticket holders about changes	1min (HIGH)
`eventzr.events.cancelled.v1`	Notify holders with refund info	1min (HIGH)

invite-svcGroup: notify-svc-invite-consumer

Topic	Description	SLA
`eventzr.invite.sent.v1`	Send event invitation	5min (NORMAL)

ticketing-svcGroup: notify-svc-ticketing-consumer

Topic	Description	SLA
`eventzr.ticketing.ticket.purchased.v1`	Send ticket confirmation + QR code	1min (HIGH)
`eventzr.ticketing.ticket.transferred.v1`	Notify both parties of transfer	1min (HIGH)

wallet-svcGroup: notify-svc-wallet-consumer

Topic	Description	SLA
`eventzr.wallet.transaction.completed.v1`	Send payment receipt	1min (HIGH)
`eventzr.wallet.balance.low.v1`	Send low balance alert	1min (HIGH)