Projections

A projection is a declarative read-model builder driven by events. It defines how event data maps onto a read model: which fields to set, how to handle collections, when to create or delete instances, and which event types to subscribe to. Chronicle evaluates projections as events arrive and keeps the resulting read models up to date.

list

Lists all projection definitions registered in the specified event store and namespace.

cratis chronicle projections list

Options

Flag	Description
-e, --event-store <NAME>	Event store to inspect. Defaults to default.
-n, --namespace <NAME>	Namespace to inspect. Defaults to Default.

Output tip

Use --output plain when you need to enumerate projections by name. The JSON format includes the full projection definition blob for each entry, which is significantly larger than the plain output. Use JSON only when you need the complete definition.

cratis chronicle projections list --output plain

Examples

List all projections:

cratis chronicle projections list

List in a specific event store:

cratis chronicle projections list -e myapp

Get projection identifiers for scripting:

cratis chronicle projections list -q

show

Shows the full projection declaration for a single projection, including all event mappings, child projections, and filters.

cratis chronicle projections show <IDENTIFIER>

Arguments

Argument	Description
IDENTIFIER	The projection identifier. Use projections list -q to retrieve identifiers.

Options

Flag	Description
-e, --event-store <NAME>	Event store to inspect. Defaults to default.
-n, --namespace <NAME>	Namespace to inspect. Defaults to Default.

Examples

Show a projection definition:

cratis chronicle projections show my-projection-id

Get the full definition as JSON:

cratis chronicle projections show my-projection-id -o json