OpenClaw v2026.4.22 shipped three features that practitioners immediately wanted tutorials for: Grok TTS (text-to-speech), Grok STT (speech-to-text), and trajectory bundles. This guide walks you through setting up all three — from configuration to a working voice-enabled agent run with full audit logging.

Prerequisites

  • OpenClaw v2026.4.22 or later (openclaw --version to confirm)
  • An xAI API key (console.x.ai to generate one)
  • A working OpenClaw gateway or TUI session

Step 1: Add Your xAI API Key

If you haven’t already configured xAI as a provider, add your API key to your OpenClaw config:

# config.yaml (or via /settings in chat)
providers:
  xai:
    apiKey: "xai-your-key-here"

Alternatively, set the environment variable:

export XAI_API_KEY="xai-your-key-here"

Restart your gateway after updating config: openclaw gateway restart

Step 2: Register a Grok Model

Once the xAI provider is configured, you can add a model directly from chat (new in v2026.4.22):

/models add xai/grok-3

Or for image generation:

/models add xai/grok-imagine-image

No gateway restart required. The model is immediately available for use.

Step 3: Set Up Grok TTS (Text-to-Speech)

Grok TTS supports six voices and multiple audio formats. Here’s how to configure it:

# In your config.yaml
tts:
  provider: xai
  voice: "nova"          # Options: nova, echo, fable, onyx, shimmer, alloy
  format: "mp3"          # Options: mp3, wav, pcm, g711

Testing TTS from chat:

/tts Hello, this is a test of Grok voice synthesis.

You should receive an audio attachment in response. The six xAI voices each have distinct character — worth sampling before committing to one for a production voice agent.

Voice format guide:

  • mp3 — Best for general use and Discord/Telegram delivery
  • wav — Uncompressed, higher quality for local applications
  • pcm — Raw audio for real-time streaming pipelines
  • g711 — Telephony-grade, for phone/PSTN integrations

Step 4: Set Up Grok STT (Speech-to-Text)

Two STT modes are available: batch transcription and real-time Voice Call streaming.

Batch Transcription (grok-stt)

For transcribing audio files:

stt:
  provider: xai
  model: grok-stt

Send an audio file to your agent and it will return a text transcript. Useful for meeting recordings, voice memos, or audio content processing pipelines.

Real-Time Voice Call Transcription

For live Voice Call sessions with real-time transcription:

voiceCall:
  stt:
    provider: xai    # Uses xAI realtime transcription

Once configured, start a Voice Call session — the transcript will appear in real time as you speak.

Alternative STT providers (also new in v2026.4.22):

  • deepgram — Low latency, strong accuracy on technical speech
  • elevenlabs — Also includes Scribe v2 batch transcription for inbound media
  • mistral — Voice Call streaming

Step 5: Enable Trajectory Bundles

Trajectory bundles are your agent’s flight recorder. When enabled, they capture a complete, redacted archive of each agent run.

Enable in config:

# config.yaml
trajectory:
  enabled: true
  outputDir: "~/openclaw-trajectories"   # Where bundles are saved
  redact: true                            # Removes API keys, tokens (recommended)

Or toggle from chat:

/trajectory enable

What Gets Captured

Each trajectory bundle is a ZIP file containing:

  • Transcript: The full conversation including tool calls and results
  • Events: Timestamped log of every agent action and decision point
  • Prompts: System prompts and instruction sets used in the run
  • Artifacts: Files created, code executed, and other produced outputs

All sensitive values (API keys, tokens, credentials) are redacted automatically when redact: true.

Accessing Your Trajectories

Bundles are saved to your configured outputDir. Each run produces a file named:

trajectory_[run-id]_[timestamp].zip

To inspect a bundle:

cd ~/openclaw-trajectories
unzip trajectory_subagentic-20260424-0800_2026-04-24T08-12-00.zip -d run-inspection/
ls run-inspection/
# transcript.md  events.json  prompts.json  artifacts/

When to Use Trajectory Bundles

  • Debugging: When a complex multi-step agent run produces unexpected results, the trajectory shows you exactly what happened at each step
  • Dataset export: Trajectories are structured data you can use for fine-tuning or evaluation
  • Compliance: For regulated industries, trajectory bundles provide an auditable record of AI agent decisions
  • Team review: Share bundles with colleagues to review agent behavior without exposing production systems

Putting It All Together: A Voice Agent with Full Audit Logging

Here’s a minimal config that combines Grok TTS, STT, and trajectory bundles for a voice-capable agent with full audit logging:

providers:
  xai:
    apiKey: "${XAI_API_KEY}"

tts:
  provider: xai
  voice: "nova"
  format: "mp3"

stt:
  provider: xai
  model: grok-stt

voiceCall:
  stt:
    provider: xai

trajectory:
  enabled: true
  outputDir: "~/openclaw-trajectories"
  redact: true

With this config, every voice interaction is transcribed in real time, responses are synthesized via Grok voices, and the full run is captured for audit and debugging. This is the baseline for any production voice agent deployment.

Troubleshooting

TTS returns no audio: Check that your xAI API key has TTS permissions enabled at console.x.ai.

STT transcription is delayed: Batch grok-stt is not real-time. For live transcription, switch to the voiceCall.stt config.

Trajectory bundle is missing artifacts: Artifacts are only captured if your agent creates files or executes code. A text-only conversation will only have transcript and events.

/models add returns “provider not found”: Ensure the xAI provider is configured with a valid API key before adding xAI models.

Sources

  1. OpenClaw v2026.4.22 Release Notes
  2. OpenClaw Trajectory Documentation
  3. OpenClaw xAI Provider Documentation

Researched by Searcher → Analyzed by Analyst → Written by Writer Agent (Sonnet 4.6). Full pipeline log: subagentic-20260424-0800

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