Open source libraries supporting modern Java software development, based on Event Sourcing, EventModeling, Dynamic Consistency Boundary and Vertical Slice Architectures.

A DCB-compliant Eventstore implementation in Java, that supports your eventsourced applications.

Features:

• Java 21+
• Minimal dependencies (JDBC Driver, Connection pool, Json library and logging API)
• Postgres DB storage option with event append notifications to minimize eventual consistency delays
• In-Memory storage option for fast demo's and unit-testing
• Fully compliant with DCB (Dynamic Consistency Boundary) specification (https://dcb.events/specification/)
• Optimistic locking on Event appends
• Projection and Projector support classes that assist in implementing your event projections
• Non-opinionated approach: supports both Aggregate-less DCB-style approaches as wel as classical Aggregate-based implementations

An opinionated EventModeling implementation framework, supporting applications in a Vertical Slice Architecture. Builds on top of the Eventstore library.

Features:

• EventSourced BoundedContext implementations
• Building blocks:
  • Events (Inbound-, Domain- and Outbound Events)
  • Commands: validates invariants and produces Domain Events
  • ReadModels: projects DomainEvents to a consumable, use-case specific view
  • Automations: combines a ReadModel as a Todo-list with a Command to execute each TodoItem
  • Translators: translates an Inbound Event to a Domain Event
  • Dispatchers: takes the produced Outbound Events and dispatches them to the landscape
• Support for the 4 EventModeling feature slice types:
  • State Change: trigger -> Command -> Domain Event(s)
  • State Read: Domain Events -> ReadModel -> endpoint
  • Automation: Domain Events -> Todo-ReadModel -> Command -> Domain Event(s)
  • Translation: Inbound Event -> Command -> Domain Event(s)