View the Custom Fields you have access to in a specific List.

Custom Fields scoped to specific custom task types include an applied_objects array on each field object. Each entry has object_type (19 for custom task type) and object_id (the custom task type ID, matching custom_item_id on tasks). Use Get Custom Task Types to resolve IDs to names. Fields without task-type scoping omit applied_objects. Workspace-scoped Custom Fields are included when querying a List.