In a CQRS architecture it typically means operations performed by the query-side of the application.

Feeding events from Serialized

Reading all events since the beginning

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

?since=0

Reading all events since the beginning

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

?since=1234

Reading events between two points in time

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

?from=2018-01-01&to=2018-02-02

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​