xAI releases Grok Voice Think Fast 1.0 via API, tops τ-voice Bench leaderboard for multi-step workflows

xAI released Grok Voice Think Fast 1.0, its new flagship voice model available via API, designed for complex, ambiguous, multi-step workflows across customer support, sales, and enterprise applications. The model takes the top spot on the τ-voice Bench leaderboard. Separately, Grok experienced intermittent outages on April 23 due to high demand following the GPT-5.5 and DeepSeek V4 launch surge.