Event Type

Every event stored in the event store must have a type associated with it.

Any client connecting to Chronicle needs to communicate the event types before any events can be appended to an event sequence.

An event type can contain multiple generations. Every new event starts with generation 1 and any changes to the event should then become a new generation. This allows versioning your event types so that multiple schema generations can coexist in the same event store.

The concept of generations is important when working with systems that evolve over time. Each generation registers its own JSON schema, which Chronicle uses to validate and store events correctly for that generation.

For detailed information on how to define and use migrations, see Event Type Migrations.