xAI launches Grok Voice Agent API, bringing Real-Time Voice AI to developers

xAI has officially launched the Grok Voice Assistant API, opening its real-time voice interaction capabilities to developers worldwide. Built on the same voice technology stack already powering millions of Tesla vehicles and mobile applications, the API now offers global access to enterprise-grade conversational voice AI.

Industry-Leading Cost Efficiency

Priced at just $0.05 per minute of connection time, Grok Voice Agent API delivers exceptional value—significantly undercutting major competitors—enabling developers to build high-performance voice applications at minimal cost.

Top Performance in Audio Benchmarks

The API ranks #1 on the Big Bench Audio benchmark for audio reasoning. With an average first-audio response time under 1 second—nearly 5x faster than its closest rival—it sets a new standard for real-time responsiveness and inference speed.

Key Features

Real-time bidirectional voice: Full-duplex, low-latency streaming for natural conversation.

Multilingual support: Native-level fluency in 100+ languages, including Chinese, with accurate handling of accents and dialects.

Automatic language detection & switching: Seamlessly identifies and adapts to user language without configuration; developers can also enforce response language via prompts.

External tool integration: Connect custom functions or leverage xAI’s real-time search across the web and X platform data.

Live web search + reasoning: Performs complex, context-aware queries during conversations.

Emotion-controlled voice: Adjust tone and expressiveness through prompt-based emotional cues.

Diverse voice personas: Choose from voices like Sal, Rex, Eve, Leo, and companion-style personas such as Mika and Valentin.

OpenAI Realtime API compatibility: Enables easy migration of existing apps and supports xAI’s LiveKit plugin for rapid integration.

What’s Next

xAI plans continuous updates, with standalone text-to-speech (TTS) and speech-to-text (STT) endpoints expected within weeks, alongside further refinements to audio models for improved pronunciation accuracy and reduced latency.

With this launch, xAI empowers developers to embed cutting-edge, affordable, and ultra-responsive voice AI into any application—ushering in a new era of intelligent, human-like voice interfaces.