Place up to 1000 voice calls in one request, all playing the same pre-uploaded audio. Upload the audio once via POST /v2/voice/audios and pass its audio_id. Each phone is validated independently — valid ones are queued and returned in accepted (each with its own message_id), invalid ones in rejected (partial success). The call result is sent per item to your configured webhook (events voice.answered / voice.no_answer / voice.failed). The batch is charged against the per-minute rate limit by its item count. Requires the SMS & Voice feature to be enabled for your account by the Clint team.