Rule-engine-based list endpoint — an alternative to the simple filter.* query params on the plain list endpoint, for building complex AND/OR filter conditions. sort_by is not validated against an enum — any field name is accepted, and request_priority is internally remapped to request_priority_index. keyword is a condition embedded inside filter_rules; if its value looks like an email address it resolves to a customer lookup by email instead of a text search. filter.module_uid restricts to specific request_uids.