imessage-voice-reply

name	imessage-voice-reply
version	1.0.1
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.