There are some use cases for which it is a helpful optimisation to group the search results based on some criteria, and then return only a limited number of those results.

An existing example of this is the $lastn operation.

More general grouping behaviour can be achieved by using the custom $group operation (for supported endpoints).

By default, this query will group results by day, and return only one result per day.


Available on: /fhir

Please see the Examples page for a walkthrough of how to interact with the endpoints.