Unconsumed-event audit

audit_unconsumed_event_types cross-references every registered event type against everything that consumes it — projections, reducers, and reactors — and reports two kinds of silent data debt:

• Unconsumed event types — data being written that no read model or reactor reads.
• Dangling references — the inverse: a consumer that references an event type id which no longer exists in the registry, typically a dead projection left behind after a refactor.

It needs no natural-language parsing and is cheap to run, which makes it a good periodic health check rather than only an ad-hoc query.

When to use it

• As a recurring audit to catch events recorded “just in case” that never became a read model.
• After a refactor, to find projections or reducers still pointing at event types that have been removed.

Parameters

Parameter	Required	Description
eventStore	no	The event store. Defaults to the configured event store.
namespace	no	The namespace to resolve observers in. Defaults to the configured namespace.

What it returns

• The number of event types considered.
• Unconsumed event types, each with its id, generation, owner, and whether it is a tombstone. The owner tells you whether it is a Client type a developer usually cares about or a framework-internal Chronicle type.
• Dangling references, each naming the missing event type id and the consumer (its type and id) that still points at it.

How consumption is determined

The audit is grounded entirely in the store’s registered definitions:

• Projections contribute the event types they read from — the keys of their From, Join, and removal definitions, walked into nested and child projections.
• Observers (reactors, reducers, and projections) contribute the event types each observes.

An event type is unconsumed when nothing in either set references it. A reference is dangling when it names an event type id that is not in the registry.

Example

Prompt: “What events are we writing that nothing reads?”

The agent calls audit_unconsumed_event_types and reports back, for example, that CartAbandoned is written but read by no projection or reactor — a candidate for either a new read model or removal — and that a LegacyOrderView projection still references a PriceQuoted event type that no longer exists.

Related

• Event catalog — the full picture of every event and its consumers, including the orphans this audit isolates.
• Read-model scaffolding — turn an unconsumed event into a read model.