| name | imessage-voice-reply |
| description | Send voice message replies in iMessage using local Kokoro-ONNX TTS. Generates native iMessage voice bubbles (CAF/Opus) that play inline with waveform — not file attachments. Use when receiving a voice message in iMessage and wanting to reply with voice, enabling voice-to-voice iMessage conversations, or sending audio responses. Zero cost — all TTS runs locally. Requires BlueBubbles channel configured in OpenClaw. |
iMessage Voice Reply
Generate and send native iMessage voice messages using local Kokoro TTS. Voice messages appear as inline playable bubbles with waveforms — identical to voice messages recorded in Messages.app.
How It Works
Your text response → Kokoro TTS (local) → afconvert (native Apple encoder) → CAF/Opus → BlueBubbles → iMessage voice bubble
Setup
bash ${baseDir}/scripts/setup.sh
Installs: kokoro-onnx, soundfile, numpy. Downloads Kokoro models (~136MB) to ~/.cache/kokoro-onnx/.
Requires: BlueBubbles channel configured in OpenClaw (channels.bluebubbles).
Generating and Sending a Voice Reply
Step 1: Generate audio
Write the response text to a temp file, then pass it via --text-file to avoid shell injection:
echo "Your response text here" > /tmp/voice_text.txt
${baseDir}/.venv/bin/python ${baseDir}/scripts/generate_voice_reply.py --text-file /tmp/voice_text.txt --output /tmp/voice_reply.caf
Alternatively, pass text directly (ensure proper shell escaping):
${baseDir}/.venv/bin/python ${baseDir}/scripts/generate_voice_reply.py --text "Your response text here" --output /tmp/voice_reply.caf
Options:
--voice af_heart — Kokoro voice (default: af_heart)--speed 1.15 — Playback speed (default: 1.15)--lang en-us — Language code (default: en-us)
Security note: The Python script uses argparse and subprocess.run with list arguments (no shell=True). Input is handled safely within the script. When calling from a shell, prefer --text-file for untrusted input to avoid shell metacharacter issues.
Step 2: Send via BlueBubbles
Use the message tool:
{
"action": "sendAttachment",
"channel": "bluebubbles",
"target": "+1XXXXXXXXXX",
"path": "/tmp/voice_reply.caf",
"filename": "Audio Message.caf",
"contentType": "audio/x-caf",
"asVoice": true
}
Critical parameters for native voice bubble:
filename must be "Audio Message.caf"contentType must be "audio/x-caf"asVoice must be true
All three are required for iMessage to render the message as an inline voice bubble with waveform instead of a file attachment.
Voice Options
| Language | Female | Male |
|---|
| English | af_heart ⭐ | am_puck |
| Spanish | ef_dora | em_alex |
| French | ff_siwis | — |
| Japanese | jf_alpha | jm_beta |
| Chinese | zf_xiaobei | zm_yunjian |
When to Reply with Voice
Reply with a voice message when:
- The user sent you a voice message (voice-for-voice)
- The user explicitly asks for an audio/voice response
Always include a text reply alongside the voice message for accessibility.
Audio Format
- macOS: CAF container, Opus codec, 48kHz mono, 32kbps — encoded by Apple's native
afconvert. Identical to what Messages.app produces.
- Fallback: MP3 via ffmpeg (works but may not render as native voice bubble on all iMessage versions).
Cost
$0. Kokoro TTS runs entirely locally. No API calls for voice generation.
Troubleshooting
Voice message shows as file attachment — Ensure all three parameters are set: filename="Audio Message.caf", contentType="audio/x-caf", asVoice=true.
First word clipped — The script prepends 150ms silence automatically. If still clipped, increase the silence pad in the script.
Kokoro model not found — Run bash ${baseDir}/scripts/setup.sh.
afconvert not found — Only available on macOS. Script falls back to ffmpeg/MP3 on Linux.
