URL reference asset. url_type declares the mechanism a receiver uses to invoke the URL (clickthrough vs. tracker_pixel vs. tracker_script) and is distinct from the URL's purpose, which the format declares in url-asset-requirements.role (clickthrough, landing_page, impression_tracker, click_tracker, viewability_tracker, third_party_tracker). Senders SHOULD include url_type on every URL asset. When url_type is absent, receivers SHOULD fall back to the format's url-asset-requirements.role per this mapping: clickthrough/landing_page → clickthrough; impression_tracker/click_tracker → tracker_pixel; viewability_tracker → tracker_script (OMID and equivalent verification SDKs require a
URL reference asset.
url_typedeclares the mechanism a receiver uses to invoke the URL (clickthrough vs. tracker_pixel vs. tracker_script) and is distinct from the URL's purpose, which the format declares inurl-asset-requirements.role(clickthrough, landing_page, impression_tracker, click_tracker, viewability_tracker, third_party_tracker). Senders SHOULD includeurl_typeon every URL asset. Whenurl_typeis absent, receivers SHOULD fall back to the format'surl-asset-requirements.roleper this mapping: clickthrough/landing_page →clickthrough; impression_tracker/click_tracker →tracker_pixel; viewability_tracker →tracker_script(OMID and equivalent verification SDKs require a