Prefer: wait=N on REST create requests allows 1–25 seconds of bounded waiting. It does not replace durable status checks. MCP create tools return a job; use get_scrape_job next.
A job can remain accepted after your client times out. Preserve its ID and idempotency key. If your deadline expires, return the ID and explain how to resume.
Cancel with POST /scrapes/{job_id}/cancel or cancel_scrape_job, using a new mutation identifier for the cancellation. Cancellation is a consequential action, not a way to stop local polling. It may be rejected if the job already completed.
See stored-result pagination and idempotency.