Ash.Query.aggregate

You're seeing just the function aggregate, go back to Ash.Query module for more information.

aggregate(query, name, type, relationship, agg_query \\ nil, default \\ nil, filterable? \\ true)

Adds an aggregation to the query.

Aggregations are made available on the aggregates field of the records returned

The filter option accepts either a filter or a keyword list of options to supply to build a limiting query for that aggregate. See the DSL docs for each aggregate type in Ash.Resource.Dsl for more information.