telemetry/v1

URI: https://docs.nylorun.com/a2a/telemetry/v1

{
  "statusUpdate": {
    "taskId": "t1.…",
    "contextId": "ticket-4821",
    "status": { "state": "TASK_STATE_COMPLETED", "timestamp": "2026-11-02T10:03:51.870Z" },
    "metadata": {
      "https://docs.nylorun.com/a2a/telemetry/v1": {
        "totals": { "steps": 114, "tokens": 2412833, "costUsd": 18.42 },
        "traceId": "4bf92f3577b34da6a3ce929d0e0e4736"
      }
    }
  }
}

The terminal status update of a task (COMPLETED, FAILED, or CANCELED) carries this extension, from the turn's end facts and its trace. Once the task has ended, GetTask and ListTasks carry it in the task's metadata too.

Field	Type	Meaning
`totals.steps`	number	The turn's steps.
`totals.tokens`	number	Tokens the turn's model calls used.
`totals.costUsd`	number	The turn's cost in US dollars, as the Runtime's Model Gate priced it.
`traceId`	string, 32 hex characters	The turn's trace id.

totals is left out when the turn recorded none.

The trace id is the caller's: send a W3C traceparent with the message and the turn joins that trace, so traceId is your trace id. Without one, it is the Runtime's own. See Trace context.