Cancel Verification

Stop a verification that has not finished.

A cancelled run is not charged and produces no verification: nothing is saved. Work already under way when you cancel (a model call in flight) is not billed to you, and the run itself stops at its next step. A run waiting on POST /verify/{task_id}/select is cancelled too.

The call is safe to repeat and answers 200 whatever the state, so a client that gives up never has to handle an error for losing a race:

• cancelled: true, status: "cancelled": the run is cancelled, by this call or an earlier one.
• cancelled: false, status: "completed": it finished first. The verification exists and was charged as usual.
• cancelled: false, status: "failed": it had already failed.

GET /verify/status/{task_id} answers cancelled from then on, and a webhook_url receives verification.cancelled (a 2026-05-13 submission receives verification.failed with failure_class: "cancelled").

Another account's task, an unknown one, and a web task answer 404. A task that is a /review's deep check answers 409 use_review_cancel: cancel the review (POST /reviews/{review_id}/cancel), which cancels everything in it.

Versions. 200: 2026-10-11 receives CancelOut, 2026-05-13 receives CancelOutLegacy; default: 2026-10-11 receives ErrorOut, 2026-05-13 receives ErrorOutLegacy.