xAI Launches Grok Voice Think Fast 1.0 for AI Phone Agents

xAI has released Grok Voice Think Fast 1.0, a voice AI model built to handle real phone conversations — not just simple question-and-answer exchanges, but complex multi-step workflows involving sales, troubleshooting, and data collection. It launched on April 25 and is available now through xAI’s API.

What Makes It Different

Most voice AI models respond to what you say. Grok Voice Think Fast reasons about what you need. The model runs a background thinking process while the conversation flows naturally, working through edge cases and catching mistakes before they reach the caller. There’s no awkward pause while it thinks — the reasoning happens in parallel with the conversation.

The model also handles structured data collection that trips up other voice systems. It can accurately capture email addresses, phone numbers, physical addresses, and account numbers even when callers speak quickly or with strong accents.

Already in Production at Starlink

This isn’t a demo or a beta. Grok Voice Think Fast 1.0 already powers Starlink’s phone support line at +1 (888) GO STARLINK, where it manages 28 different tools across hundreds of workflows. The results xAI reports are striking: a 20% sales conversion rate from phone inquiries and 70% of customer support issues resolved without a human agent.

Benchmarks and Pricing

The model tops the τ-voice Bench leaderboard at 67.3%, ahead of Gemini, GPT Realtime, and xAI’s previous voice model. It supports more than 25 languages. API access costs $0.05 per minute — competitive for a model at this capability level.

What This Means for You

If you run a business that handles phone calls — support, sales, appointments, intake — this is worth paying attention to. Voice AI has been mediocre for years, mostly limited to rigid menu systems and basic routing. A model that can reason, use tools, and handle messy real-world conversations changes what’s possible.

For developers, the $0.05-per-minute API opens the door to building custom voice agents without massive infrastructure costs. Combined with xAI’s standalone speech-to-text and text-to-speech APIs, there’s now a full voice AI stack available from a single provider.

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