Event Feed API


The Event Feed API automatically exposes a unique feed of events for each aggregate type that you can use to build queryable data or implement side-effects to connect your system to other services. In a CQRS architecture it typically means operations performed by the query-side of the application.

Sequence numbers

When an event batch is persisted in the store it is assigned a sequence number. Each feed has its own ever increasing sequence number. This number is what the feed subscribers use to keep track of how much of the feed has been consumed. The number is guaranteed to be a unique, ever increasing, positive integer.

List all event feeds


Reading all events by aggregate type


Reading all events independent of aggregate type

The API includes a special endpoint called _all that returns events for all aggregate types, in insertion order.


Reading all events since the beginning

Simply pass a zero, or exclude the parameter from the request to receive everything since the beginning.


Reading new events since last received event

Append the sequenceNumber of the last received event as a since parameter to limit the response to only include events since then.


Reading events created within two points in time

It’s possible to get all events within a given period by specifying the from/to date/time range.


Default value for from is 1970-01-01 and to is now, if not specified in the request. The string should follow the ISO 8601 format specified in RFC 3339, section 5.6