Most people use OpenClaw as a text-based AI assistant. You ask a question, it replies, and that’s usually where the interaction ends. What many people don’t realize is that OpenClaw also has powerful voice capabilities. With the right setup, it can understand spoken commands, respond naturally with speech, and even handle phone calls on your behalf.

Voice AI is becoming increasingly valuable for both businesses and individuals. Gartner estimates that conversational AI will help contact centers save around $80 billion in labor costs in 2026, largely because AI voice agents can handle calls for about $0.40 per call, compared to $7–$12 for a human representative. As voice technology becomes more affordable and capable, it’s no longer just an extra feature; it’s a practical way to automate customer support, personal assistance, and everyday workflows.

You’ll learn how to turn OpenClaw into a fully functional voice AI assistant by choosing the right voice setup, configuring speech recognition, enabling natural-sounding voice responses, and preparing everything for a reliable production deployment.

Step 1: Pick the Right Voice Mode: Don’t Default to the First One

OpenClaw doesn’t do voice one way; it does it four ways, and each is built for a different job. Choosing wrong here means rebuilding later, so it’s worth five minutes of thought before any configuration.

• STT + TTS (Chat Mode): the lightest option. It turns voice notes in WhatsApp, Telegram, or Slack into text, and text responses back into audio. Good for async, message-based use.
• Voice Call Plugin: real inbound and outbound phone calls over SIP providers like Twilio, Telnyx, or Plivo, with full-duplex audio and live transcription. This is the one for actual phone-based support or outreach.
• Push-to-Talk (Clawkie Talkie): a web interface for hands-free dictation and long-form voice notes, wired straight into your existing OpenClaw session. Built for productivity, not conversation.
• Real-time Voice (Stimm Voice): the most ambitious mode: low-latency, natural back-and-forth conversation, powered by LiveKit for audio transport with OpenClaw handling the reasoning underneath.

If you’re supporting customers over the phone, you want the Voice Call Plugin. If you just want richer WhatsApp interactions, Chat Mode is plenty. Pick based on the interaction you’re actually building, not the one that sounds coolest.

Step 2: Give OpenClaw Ears (Speech-to-Text)

Before OpenClaw can respond to anything spoken, it needs to understand it. The fastest path to working STT is Groq’s hosted Whisper:

1. Grab a free Groq API key at groq.com; the free tier gives you 1M tokens a month, which is plenty for testing.
2. In ~/.openclaw/openclaw.json, add STT config under tools.media.audio using whisper-large-v3.
3. Drop your API key into models.providers.groq.

OpenClaw accepts most common audio formats out of the box, MP3, WAV, M4A, OGG, WEBM, and more, so you rarely have to think about conversion. If Groq isn’t your thing, Deepgram, ElevenLabs Scribe v2, OpenAI, xAI, and Mistral all plug in as alternatives for streaming transcription.

Step 3: Give It a Voice (Text-to-Speech)

OpenClaw supports 14 TTS providers, but you don’t need to survey all of them to get started. Microsoft Edge TTS requires zero API key and sounds perfectly natural in English:

json

{

  “messages“: {

    “tts“: {

      "auto": "always",

      “provider“: “microsoft“

    }

  }

}

For Chinese output, specify a voice explicitly: zh-CN-XiaoxiaoNeural (晓晓, female), zh-CN-YunxiNeural (云希, male), or zh-CN-XiaoyiNeural (晓伊, female) are the common picks. Once the basics work, you can tune rate, pitch, and output format to taste.

When free-tier quality stops being enough, three paid providers stand out: ElevenLabs for voice cloning and deterministic output via a seed value, OpenAI for persona-driven instructions, and Volcengine (Doubao), which is tuned specifically for Chinese and supports emotion control.

Step 4: Wire Up the Actual Channel

This is where the mode you picked in Step 1 becomes real infrastructure.

• Voice messages in existing channels need nothing extra; once STT and TTS are configured, OpenClaw automatically handles voice notes sent through Telegram, WhatsApp, and similar channels.
• Phone calls over SIP require installing the SIP plugin (openclaw plugins install openclaw-sip-voice) plus system dependencies on Ubuntu/Debian: python3-dev, portaudio19-dev, and ffmpeg.
• Twilio, Telnyx, or Plivo calls need the voice-call plugin configured with provider credentials, a “from” number, and a publicly reachable webhook URL, then a readiness check via openclaw voicecall setup.

Step 5: Actually Call Yourself

Configuration without a test is just hope. Place a real outbound call:

bash

openclaw voicecall call –to “+15555550123” –message “Hello from OpenClaw“

Or run the smoke test, which is a dry run unless you force it:

bash

openclaw voicecall smoke –to “+15555550123” –yes

Calls run in one of two modes: notify, which plays a message and hangs up, or conversation, which stays open for real back-and-forth. Test both if your use case needs them; they behave differently enough that assuming one covers the other is a mistake.

Step 6: Let It Call You First

The most useful voice assistants aren’t purely reactive. OpenClaw can initiate calls on its own, triggered by outbound notifications from cron jobs or HTTP requests, or by scheduled heartbeats for proactive check-ins. It also supports DTMF tones during live calls, so it can navigate phone menus or enter PINs on your behalf.

Once a call is active, a small set of commands controls it: continue speaks and waits for the caller’s reply, speak talks without waiting, dtmf sends tones, end hangs up, and status reports what’s currently happening. Together, they’re enough to build genuinely interactive phone flows, not just glorified voicemail drops.

Step 7: Make It Production-Grade

A voice assistant that only works on your laptop isn’t done. A few things aren’t optional before you point real traffic at it:

• HTTPS is mandatory. Meta and Twilio simply won’t accept insecure webhook URLs; there’s no fallback here.
• Use a stable public URL. A real domain or Tailscale funnel in production; ngrok is fine for development, but its URLs shift and will quietly break things if you rely on them long-term.
• Lock down the gateway. Set allow-from lists to control who can call in, and keep signature verification enabled; Twilio and Telnyx enforce it, and disabling it in production is a real security gap, not a shortcut.
• Decide your session scope. Per-phone keeps conversation memory across repeat calls (the default), while per-call starts fresh every time, better suited to IVR, reception, or booking flows where context shouldn’t carry over.
• Watch it run. OpenClaw voice call tail streams live call logs, and OpenClaw voice call latency reports turn-latency metrics so you catch slowdowns before users do.

Troubleshooting Common Voice Issues

Most voice-related problems can be traced back to microphone permissions, incorrect API credentials, or networking issues. Testing each component individually, STT, TTS, and the voice channel, usually makes troubleshooting much easier.

Build Your Own Private Voice Assistant

Adding voice capabilities to OpenClaw opens up far more possibilities than a traditional text chatbot. With the right combination of speech-to-text, text-to-speech, and voice integrations, you can build an AI assistant that understands spoken commands, responds naturally, handles phone calls, and automates voice-based workflows for personal or business use.

Whether you’re creating a hands-free productivity assistant, a WhatsApp voice bot, or an AI-powered receptionist, OpenClaw gives you the flexibility to choose the voice experience that best fits your needs.

As your requirements grow, you can expand your setup with more advanced voice providers, telephony integrations, and real-time conversations without rebuilding your workflow from scratch.

Ready to keep your voice assistant online 24/7? Host OpenClaw on a reliable managed server with secure deployment, automatic updates, and the resources needed for always-on voice automation.