Grok Voice API adds Custom Voices with two-stage anti-misuse verification

xAI launched Custom Voices on its Grok Voice API, enabling voice cloning that captures natural emotion and delivery patterns in addition to timbre. The feature, debuting alongside Grok 4.3, generates production-ready voice models from about one minute of natural speech in under two minutes for use across TTS and Voice Agent APIs. A two-stage security check is implemented to prevent misuse.