Aggregations
V4 offers two aggregation modes — facets (records + facet counts) and group_by (facet counts only) — driven by the fields marked as Facetable in each entity's filter fields reference.
Not available for persons
No person fields are facetable, so the facets and group_by parameters are not available on the persons endpoint. Requests using them return a 400 error.
See Aggregations for research products for how the two modes work on entities that support them.