Relay Domain Context

What Is Relay?

Relay handles events, notifications, and data feeds across the Violet platform. It's the central nervous system for asynchronous communication.

Core Capabilities

Event Processing

• Kafka-based event streaming
• Event routing and transformation
• Dead letter queue handling
• Event replay capabilities

Notifications

• Webhook delivery to external systems
• Email notifications
• In-app notifications
• Notification preferences management

Feed Management

• Product feed generation
• Order feed updates
• Inventory feed synchronization
• Custom feed formats

Key Kafka Topics

| Topic Pattern | Purpose | |---------------|---------| | orders.order.* | Order lifecycle events | | products.product.* | Product update events | | merchants.merchant.* | Merchant account events | | fulfillment.* | Fulfillment tracking events | | inventory.* | Stock level changes |

Event Schema Pattern

{
  "event_type": "order.created",
  "event_id": "uuid",
  "timestamp": "2024-01-01T00:00:00Z",
  "version": "1.0",
  "payload": {
    "order_id": 12345,
    "app_id": 67890
  },
  "metadata": {
    "source": "OrderService",
    "correlation_id": "uuid"
  }
}

Key Repositories

| Repo | Purpose | |------|---------| | FeedManagementService | Feed generation and delivery | | NotificationService | Notification routing | | EventBridge | Event processing infrastructure |

Integration Points

• Beam: Receives fulfillment events, sends order confirmations
• Prism: Receives order events, sends inventory updates
• Channels: Webhook delivery for order/fulfillment updates
• Merchants: Store update notifications