TaskEnded

A delegated task ended (design 4.47): durable, committed with the task call's terminal result - a report, or a refusal the parent model sees as a tool error - so once per child. A call that fails its parent (under ChildFailure.Fail) commits nothing, and its replay sends the one TaskEnded.

status is completed, blocked:<guardrail>, step_limit_reached, token_limit_reached, output_invalid or failed; a call whose child suspended commits none until a resumed call settles it. usage is the child's whole life's model usage, every attempt and phase, the roll-up added to the parent. duration runs from the child's first admission (RunOrigin.startedAt) to the call's end, by the runtime's clock; it is encoded in milliseconds. No request, report or reason: the child's own log and the parent's tool message hold those (rule 9). It is the source of per-subagent count, latency, outcome and token metrics.