add_item is not an event, rather a command/ request that is yet to be validated. item_added is the event = a fact that was 'allowed to happen' by the system.
Keeping commands in a persistent store is a matter of choice but not necessary. I've seen people doing command sourcing and calling it event sourcing.
Keeping commands in a persistent store is a matter of choice but not necessary. I've seen people doing command sourcing and calling it event sourcing.