#What it is
A NestJS CQRS module for EventStoreDB. It gives @nestjs/cqrs a durable event store: persistent and catch-up subscriptions, projections, and the wiring between them.
#Where it came from
It was the event-sourcing layer inside Ultimate Backend. People kept opening issues asking how to use only that part, which is a reliable signal that a piece wants to be its own package.
#What it taught me
Event sourcing is straightforward until you need to change an event's shape. Versioning events, upcasting old ones on read, and deciding whether a projection rebuild is safe are the actual work, and none of them are visible in a tutorial. That lesson is directly upstream of Fabriq's decision to make every event versioned and every projection rebuildable from the start rather than as a later retrofit.