Task-level status literal. Discriminates this async envelope from the synchronous success shape, whose creatives array carries per-item approval state via CreativeStatus. See task-status.json for the full task-status enum.
Task handle the buyer uses with tasks/get, and that the seller references on push-notification callbacks. The creatives array is issued on the completion artifact, not here. Per AdCP wire conventions this is snake_case; A2A adapters MAY surface it as taskId, but the payload field emitted by the agent is task_id.
OptionalmessageOptional human-readable explanation of why the task is submitted — e.g., 'Batch ingestion queued; typical turnaround 15-30 minutes.' Plain text only. Buyers MUST treat this as untrusted seller input: escape before rendering to HTML UIs, and sanitize or isolate before passing to an LLM prompt context — a hostile seller may inject prompt-injection payloads aimed at the buyer's agent.
OptionalerrorsOptional advisory errors accompanying the submitted envelope. Use only for non-blocking warnings (e.g., throttled_severity advisories, governance observations). Terminal failures belong in the error branch, not here.
OptionalcontextOptionalext
Async task envelope returned when the whole sync operation cannot be confirmed before the response is emitted — for example, when the seller batches ingestion, when async review must settle before per-item results can be issued, or when governance review gates the sync. The buyer polls tasks/get with task_id or receives a webhook when the task completes; the creatives array with per-item action/status lands on the completion artifact, not this envelope. Per-item async review (an item in pending_review while the rest of the sync resolves synchronously) belongs on the SyncCreativesSuccess branch with status: pending_review, not here.