Complete Guide: xAI Voice Agent Builder
xAI's Voice Agent Builder is a no-code platform that lets you create and deploy human-like voice agents that answer full phone calls — in under two minutes.
Let Grok Answer Your Phone Beta – Launched July 1, 2026
xAI's Voice Agent Builder is a no-code platform that lets you create and deploy powerful, human-like voice agents in under two minutes. These agents handle full phone calls using Grok's advanced low-latency speech-to-speech technology.
What It Is
Voice Agent Builder turns plain English instructions into production-ready phone agents. It combines telephony, knowledge retrieval, tool integrations, guardrails, and observability into one simple interface — no coding or gluing together separate services required.
Key Capabilities
- Full Call Handling: Manages entire inbound and outbound calls end-to-end.
- Natural Conversations: Sub-second latency, handles interruptions, noise, accents, and real-world messiness.
- Context Memory: Keeps the full conversation history for the duration of the call.
- Knowledge Base: Real-time retrieval from uploaded documents.
- Tools & Actions: Integrates with Google Calendar, Gmail, Notion, custom APIs, and more.
- Guardrails & Escalation: Define rules and transfer to humans when needed.
- Voice Options: 80+ built-in voices (including multilingual) or clone your own.
- Observability: Automatic recording, transcription, summaries, and real-time monitoring.
- Languages: Supports 25+ languages.
Step-by-Step Setup
- Write the Playbook
Describe the desired call flow in plain English. Example: "Greet the caller warmly as Sam's Office. Ask for their name and reason for calling. Look up their appointment in Google Calendar. Confirm or reschedule as needed. End by thanking them and sending a confirmation email."
- Upload Knowledge
Attach PDFs, Word docs, Excel files, Markdown, or other documents. The agent retrieves relevant info in real-time during calls.
- Connect Tools
Link integrations like Google Calendar, Gmail, Notion, or your own APIs via MCP (Model Control Protocol) for actions like booking, emailing, or updating records.
- Set Guardrails
Define boundaries, e.g., "Never share credit card details" or "Escalate to human if the caller requests a refund over $100."
- Choose Voice & Greeting
Select from 80+ voices or clone your own voice using just ~2 minutes of natural speech. You fully control the greeting and what the agent says (e.g., "Hi, you've reached Sam's Office. How can I help you today?"). It does not have to identify as Grok.
- Assign a Phone Number
Use the free number provided with your account, or connect your existing number via direct SIP from any major provider.
- Test & Deploy
Test instantly in the browser (changes take effect immediately). Go live when ready.
Voice Cloning Details
- Requires only about 2 minutes of natural speech.
- Produces highly realistic results — often indistinguishable in blind tests for many users.
- 30 free clones per account.
- Works well in English; may sound slightly less emotional in very long or intense calls.
Call Management & Memory
- During the Call: Full session context is maintained automatically — the agent remembers everything said earlier in that call.
- Across Calls: No automatic long-term memory between separate calls (you can implement this manually via tools/databases if needed).
- Recording & Notation: Every call is automatically recorded, transcribed, and summarized. You get full audio, transcript, tool usage traces, and notifications. Review or monitor live as desired.
Outbound Calls
- Supported via the Grok Voice API and integrations.
- Native outbound flows in the no-code builder are rolling out/improving rapidly.
Legal & Compliance Notes
- Recording Announcement: Not required by the tool. You decide what (if anything) the agent says.
- Consent: Follow local laws. One-party consent is federal standard in the US, but ~12 states require all-party consent. Best practice: Include a brief "This call may be recorded for quality purposes" at the start. Consult a lawyer for your jurisdiction.
Pricing
- $0.05 per minute of audio (voices included).
- Free phone number with every account.
- Generous free tier for testing.
Limitations (Beta)
- Still in beta — occasional quirks possible.
- Voice clones can feel slightly flat in highly emotional moments.
- Advanced multi-call memory requires custom setup.
- Outbound calling is functional but becoming more seamless.
Best For
- Customer support
- Appointment booking/scheduling
- Sales qualification
- Personal assistants
- Small business receptionists
Try it at x.ai/voice or in the xAI console.
This guide is based on official xAI announcements and documentation as of July 2026. Features may evolve quickly in beta.