Free extension contract

Use doctoucan_document_actions, doctoucan_library_query_args, doctoucan_library_classes, doctoucan_product_resource_ids, doctoucan_product_resources and doctoucan_product_resource_classes. Core re-sanitizes actions and CSS classes.

Data contract

doctoucan_document remains canonical. Never register another paid Document CPT or copy content into products. Treat Attachment IDs and External URLs as mutually exclusive sources.

Compatibility

Preserve server rendering, ordinary navigation, escaping, visible focus and the no-JavaScript baseline. WooCommerce order checks must use public CRUD APIs and pass HPOS acceptance.