A centralized module containing versioned, immutable Kafka event DTOs used across the DevSocket eCommerce microservices ecosystem. This library ensures consistency, reusability, and clean separation of domain events from infrastructure logic.

• ✅ Share event definitions across services
• ✅ Enable schema versioning and evolution
• ✅ Promote immutability and serialization safety
• ✅ Decouple business logic from transport concerns

Microservice A
    └── Depends on common-event-models
    └── Uses shared Kafka DTOs

Microservice B
    └── Depends on common-event-models
    └── Uses same DTOs for consuming events

Kafka Topic
└── Transports serialized common-event-models DTOs

• Java Records: All DTOs use record for immutability and clarity
• EventType Enums: Each DTO includes an EventType to distinguish lifecycle stages
• Timestamp Field: Every event includes a timestamp for ordering and audit
• Nested Records: Used for structured sub-objects like Address, CartItem, etc.

Add this module as a dependency in your microservice:

<dependency>
  <groupId>com.devsocket.ecommerce</groupId>
  <artifactId>common-event-models</artifactId>
  <version>1.0.0</version>
</dependency>

Then import and use the DTOs:

import com.devsocket.ecommerce.events.user.UserEvent;

UserEvent event = new UserEvent(
    userId,
    email,
    fullName,
    phoneNumber,
    new UserEvent.Address(...),
    UserEvent.EventType.REGISTERED, Instant.now());

These DTOs are designed to work with:

• ✅ JSON (default Spring Kafka)

• ✅ Avro / Protobuf (with annotations if needed)

• ✅ Schema Registry (for versioning and compatibility)

Semantic versioning (MAJOR.MINOR.PATCH) Breaking changes (e.g., field removal or type change) require a major version bump Additive changes (e.g., new fields) are backward-compatible

Feel free to submit PRs for: New event types Schema enhancements Serialization improvements