Based on those requirements, we decided to make the Event Sourcing framework an implementation detail of the back-end. The event sourcing implementation is not surfaced to GraphQL. The client application consuming the GraphQL API is not aware there is some Event Sourcing going on behind the scene.
We wanted the Aggregates to be regular ActiveRecord models that follow patterns that you’d find on a regular Rails application. This way, we could remove the Event Sourcing framework altogether and replace it with in-place data mutation: create!, update! and destroy! calls.
We looked at various Event Sourcing frameworks written in Ruby but most of them were actually too complex for our needs or would store data in a way that was too different from your regular Rails app. So we decided to build our own minimal framework. It’s about 200 lines of code.

Site for the Nact project.