Get Folder Facets
Returns every attribute available on media within a folder, with distinct-item counts. The returned filter_key on each facet can be passed back to Get Folder Contents as part of attributes= to filter the listing. Per-template exclusion: when computing counts for a facet, filters on that same template_key are ignored; filters on other templates still apply. This matches the OR-within-template / AND-across-template filter semantics so users can multi-select within a template and still see realistic counts for the other values.
Query Parameters
Filter by type: image, video, file, all (default: all)
Filter by attribute(s). Same syntax as Get Folder Contents: repeat the query parameter once per filter, each in the form template_key/attribute_key. Per-template exclusion applies when computing counts (filters on the same template_key are ignored).