list_creative_formats is deprecated in AdCP 3.2. It combined three different questions into one agent-global list and therefore could not accurately describe publisher acceptance, product deliverability, and creative production at the same time.
Existing 3.x agents MAY continue serving the task for compatibility. New implementations MUST use the canonical surfaces below and SHOULD derive any legacy response mechanically from canonical declarations rather than maintaining a second catalog. The task follows its own compatibility schedule; removal of exact plural format_ids fields in AdCP 4.0 does not itself remove this task.
Use the surface that owns the fact
Sales agents MUST NOT use an agent-global format list as a purchasability promise. Product
format_options[] is the closed sellable set, and placement declarations may narrow it.
Creative agents advertise stable build routing separately from publisher/product format identity:
streamhaus_vertical_video as target_capability_id to build_creative. The returned manifest carries canonical format_kind: "video_hosted"; capability IDs never appear on products or manifests.
Registry reverse discovery
The AgenticAdvertising.org registry indexes canonical creative capabilities. To find creative agents that claim they can build an exact publisher format:format_kind.
Compatibility behavior
The deprecated request and response schemas remain available at:/schemas/3.2.0-beta.0/media-buy/list-creative-formats-request.json/schemas/3.2.0-beta.0/media-buy/list-creative-formats-response.json
- Keep canonical declarations as the only authored source.
- Project named formats only for a peer that still requires them.
- Never infer a publisher catalog from one seller’s products.
- Never return publisher-declared formats as if every format were deliverable by the responding sales agent.