Customer support automation
Answer policy questions, retrieve order or account details, update records, and transfer calls that need a person.
Independent tool overview
Grok Voice Agent at a glance
Grok Voice Agent is xAI's active speech-to-speech platform for building phone and web agents that can reason, call tools, search current public information, and speak across more than 25 languages. The original API has expanded into a broader Grok Voice suite with a no-code Voice Agent Builder and the newer Think Fast 2.0 model.
Visit the official Grok Voice Agent site ↗
- Best for
- Tool-using support, sales, booking, and service calls
- Current model
- Grok Voice Think Fast 2.0
- Languages
- 25+
- Channels
- WebSocket, WebRTC, SIP, LiveKit, and browser testing
- Current agent rate
- $0.08 per audio minute for Think Fast 2.0
Overview
What Grok Voice Agent is
Grok Voice Agent began as a realtime developer API and now supports two main paths: a WebSocket, WebRTC, SIP, or LiveKit integration for developers, and a no-code builder for configuring production agents with prompts, knowledge, tools, guardrails, telephony, and call review.
The platform uses a speech-to-speech model rather than requiring customers to assemble separate transcription, language-model, and voice-synthesis providers. Agents can have multi-turn conversations, invoke business functions, search the web or X, retrieve from uploaded knowledge, and transfer a caller to a person.
xAI has already advanced the model line beyond the original launch. Its current pricing documentation lists Grok Voice Think Fast 2.0 at $0.08 per audio minute; the older Think Fast 1.0 price of $0.05 per minute is marked deprecated.
Production voice automation still requires substantial operational work. Teams need verified tool permissions, consent and recording disclosures, escalation paths, adversarial testing, monitoring, cost controls, and human review for high-impact workflows.
Use cases
Who Grok Voice Agent is best for
The strongest fit depends on the job you need the product to complete, not the size of its feature list.
Booking and qualification
Collect structured information, call scheduling or CRM tools, and confirm the result during a live conversation.
Developers consolidating a voice stack
Use one realtime speech-to-speech service instead of separately orchestrating transcription, an LLM, and text-to-speech.
Capabilities
Core Grok Voice Agent features
Realtime speech-to-speech
Stream audio bidirectionally for full-duplex conversations with interruption handling and sub-second latency claims.
Function and MCP tool use
Connect the agent to REST or GraphQL APIs, business systems, calendars, CRMs, and remote MCP servers.
Web and X search
Let an agent retrieve current public information when the answer is not contained in its instructions or knowledge base.
Knowledge retrieval
Attach collections of business documents so policies, product specifications, and runbooks can be retrieved during calls.
Voice Agent Builder
Configure prompts, voices, phone access, knowledge, tools, guardrails, and monitoring without writing the complete application.
Telephony and handoff
Use an included number, bring a number over SIP, accept keypad input, and transfer a caller to a human.
Call review
Record and transcribe calls, inspect tool use, and review how the agent handled the interaction.
OpenAI Realtime compatibility
Most OpenAI realtime client libraries can connect by changing the WebSocket endpoint, though xAI documents event differences and unsupported events.
Process
How the Grok Voice Agent workflow works
Step 1
Define a narrow call flow
Specify the supported intents, required disclosures, authentication steps, prohibited actions, and exact conditions for human transfer.
Step 2
Attach least-privilege tools
Give each action the minimum permissions needed, validate inputs server-side, and require confirmation for irreversible or sensitive changes.
Step 3
Test hostile and messy calls
Cover accents, noise, interruptions, silence, prompt injection, ambiguous requests, incorrect records, fraud attempts, and unavailable systems.
Step 4
Launch with monitoring
Review recordings, transcripts, tool traces, transfers, task success, complaints, latency, and cost before expanding scope.
Cost
Grok Voice Agent pricing and free plan
Grok Voice is usage-based. xAI's current API pricing page lists Think Fast 2.0 at $0.08 per audio minute plus $0.004 for text input. The older $0.05-per-minute Think Fast 1.0 rate is deprecated, although some marketing pages still show pricing starting at $0.05. Separate transcription, text-to-speech, telephony, storage, and server-side tool charges can also apply.
Think Fast 2.0 speech-to-speech
$0.08 per audio minute
Current flagship realtime voice-agent model.
- $4.80 per audio hour
- $0.004 for text input
- Additional server-side tools are metered separately
Think Fast 1.0 speech-to-speech
$0.05 per audio minute
Older model retained in the pricing table but marked deprecated.
- $3.00 per audio hour
- $0.004 for text input
- Do not plan a new production deployment around a deprecated model
Text to Speech
$15 per 1M characters
Standalone speech synthesis rather than a complete conversational agent.
- Multiple output formats and telephony codecs
- Voices and pronunciation controls available
Speech to Text
$0.10/hour batch; $0.20/hour streaming
Standalone transcription for files or live streams.
- Batch REST processing is less expensive
- Streaming is intended for live use
Builder telephony
$0.01 per minute additional
Published telephony charge for calls on xAI's included provisioned number.
- Each Builder account includes a phone number
- Bring-your-own SIP carrier costs are separate
- Voice-agent usage is charged in addition
Pricing checked . Check current pricing at the source ↗
Assessment
Grok Voice Agent strengths and limitations
Where it stands out
- Integrated speech-to-speech stack reduces the number of realtime vendors and handoffs
- Supports tools, knowledge retrieval, web search, X search, telephony, and human transfers
- No-code Builder gives operators a faster path to a working test agent
- Developer paths cover WebSocket, WebRTC, SIP, and LiveKit
- Current pricing is simple enough to model per call before tool and carrier charges
- Call recordings, transcripts, and tool traces support quality review
What to consider
- The headline $0.05-per-minute rate on some pages is not the current flagship price; Think Fast 2.0 is listed at $0.08 per minute
- Server-side search, file retrieval, storage, telephony, and external systems can add to the apparent base cost
- Voice agents can mishear callers, hallucinate policy, invoke the wrong tool, or mishandle ambiguous instructions
- Recorded calls and cloned voices create consent, privacy, biometric, disclosure, and retention obligations that vary by jurisdiction
- High-impact transactions need strong authentication, least-privilege permissions, confirmations, audit logs, and human escalation
- OpenAI Realtime compatibility is not exact; xAI documents renamed and unsupported events
Compare
Grok Voice Agent alternatives
The right alternative depends on the specific output, workflow, controls and budget your project requires.
Sales
Vapi
Consider Vapi for a provider-agnostic voice-agent orchestration layer with broad model and telephony choices.
Explore Vapi →Business Operations
Retell AI
Consider Retell AI for another managed platform focused on production phone agents, analytics, and call operations.
Explore Retell AI →Content Creator
ElevenLabs Text To Speech GPT
Consider ElevenLabs when voice quality and standalone speech generation are more important than Grok's integrated agent reasoning.
Explore ElevenLabs Text To Speech GPT →Questions
Grok Voice Agent FAQs
What is Grok Voice Agent?
It is xAI's realtime speech-to-speech platform for web and phone agents. It can hold multi-turn conversations, call business tools, retrieve from documents, search the web or X, and hand calls to a person.
How much does Grok Voice Agent cost?
The current Think Fast 2.0 model is listed at $0.08 per audio minute plus $0.004 for text input. The older Think Fast 1.0 rate of $0.05 per minute is deprecated. Telephony, search tools, storage, and other services can add charges.
Can I build a Grok voice agent without code?
Yes. xAI's beta Voice Agent Builder lets users configure an agent, knowledge, tools, guardrails, voice, phone access, and call review through a no-code interface. Custom integrations can still use the API.
Does Grok Voice Agent support phone calls?
Yes. The Builder includes a phone number, and developers can connect their own carrier or PBX over SIP. xAI also supports phone keypresses and human call transfer.
Is it safe to let the agent take business actions?
Only with careful controls. Validate every tool call on your server, limit permissions, authenticate callers, confirm sensitive actions, prevent secret disclosure, monitor calls, and provide a reliable human handoff.
Bottom line
Our Grok Voice Agent verdict
Grok Voice Agent is a compelling option for teams that want reasoning, speech, tools, search, and telephony in one platform, especially now that xAI offers both APIs and a no-code Builder. The deciding factor should be production evaluation on your hardest real calls—not a latency claim or demo—and the budget should use the current Think Fast 2.0 price plus every tool and carrier cost.
Visit Grok Voice Agent website ↗Similar Agents Tools
View all Agents AI tools →
MAI-UI
MAI-UI - Alibaba's AI agent that can autonomously control smartphone apps and complete multi-step tasks on mobile devices
Claude Cowork
Claude Cowork - Anthropic's new MacOS tool that brings Claude Code's agentic capabilities to everyday tasks
Claude in Chrome
Claude in Chrome - Agentic browser extension to use Anthropic's Claude directly in Google Chrome
Skills
Skills - Vercel's open ecosystem for agent skills
AI training for the future of work.
Get access to all our AI courses, hundreds of real-world AI use cases, live expert-led workshops, an exclusive network of AI early adopters, and more.
AI Courses
Get unlimited access to all of our current & upcoming industry-specific AI courses for the duration of your subscription.
Daily Guides
To keep up with the rapid pace of AI, our team publishes AI implementation guides daily. Our library contains 300+ practical use cases to automate real-world work.
Workshops
Join weekly, live, interactive sessions with industry leaders who are at the forefront of AI for hands-on implementation guidance and exclusive insights.
Community
Network with an exclusive community of AI-first professionals who are working smarter with AI. Learn how early adopters are using AI in their work and businesses.