Choosing your starters

Pick exactly the starters you need — each wires the right libraries automatically; multiple storage techs can run in parallel.

Full-stack bundles

Use one of these when you want event sourcing and CQRS together out of the box.

The two bundles are not mutually exclusive — put both on the classpath to mix @JsonProjection and @JpaProjection read models in the same application. They share the event store, command/query bus, saga support, and the relational projection bookkeeping (contributed once), so combining them only adds the second read-model store.

spring-ddd-starter-jdbc: Event sourcing + CQRS + JSON @JsonProjection read models over plain JDBC. No Hibernate dependency. This is the recommended starting point for new services.
spring-ddd-starter-jpa: Event sourcing + CQRS + JPA @JpaProjection read models via Hibernate. Use when you need a full JPA entity model for your read side.

À-la-carte starters

Add only what you need. These compose freely with each other and with the full-stack bundles.

spring-ddd-starter-eventsourcing-jdbc: Event-sourcing persistence only (JDBC). Activate when you need event sourcing without the CQRS stack.
spring-ddd-starter-cqrs-jdbc: The CQRS command and query bus with JSON @JsonProjection read models persisted over plain JDBC.
spring-ddd-starter-cqrs-jpa: The CQRS command and query bus with JPA @JpaProjection read models via Hibernate.
spring-ddd-starter-saga-jdbc: Process-manager (saga) support over JDBC. Adds durable saga state and deadline scheduling.
spring-ddd-starter-domain-events: Async @DomainEventHandler dispatch without the ES/CQRS stack. Use when you want decoupled event handlers in a non-event-sourced service.

Actuator add-ons

spring-ddd-starter-eventsourcing-actuator: /actuator/eventstore endpoint + event-store health indicator and metrics.
spring-ddd-starter-cqrs-actuator: /actuator/projections endpoint + projection health and metrics.
spring-ddd-starter-saga-actuator: /actuator/sagas endpoint + saga health and metrics.

Decision table

I want to… Use

I want to…	Use
Full ES + CQRS, JSON read models (no Hibernate)	`spring-ddd-starter-jdbc`
Full ES + CQRS, JPA read models	`spring-ddd-starter-jpa`
Event sourcing only	`spring-ddd-starter-eventsourcing-jdbc`
CQRS only, JSON read models	`spring-ddd-starter-cqrs-jdbc`
CQRS only, JPA read models	`spring-ddd-starter-cqrs-jpa`
Add process managers to any of the above	+ `spring-ddd-starter-saga-jdbc`
Async domain-event handlers, no ES/CQRS	`spring-ddd-starter-domain-events`

Full ES + CQRS, JSON read models (no Hibernate)

spring-ddd-starter-jdbc

Full ES + CQRS, JPA read models

spring-ddd-starter-jpa

Event sourcing only

spring-ddd-starter-eventsourcing-jdbc

CQRS only, JSON read models

spring-ddd-starter-cqrs-jdbc

CQRS only, JPA read models

spring-ddd-starter-cqrs-jpa

Add process managers to any of the above

+ spring-ddd-starter-saga-jdbc

Async domain-event handlers, no ES/CQRS

spring-ddd-starter-domain-events

Multiple storage techs may run in parallel in a single application. For example, a service can use spring-ddd-starter-jdbc and still declare JPA entities for other purposes.

For event-sourcing depth, see Event-Sourcing. For projection and query details, see CQRS.