Supertonic TTS
/install supertonic-tts
Supertonic TTS Skill
Local, multilingual text-to-speech powered by Supertone's Supertonic ONNX model.
Core Features
- 100% offline — No API key, no cloud, no network. Runs on-device via ONNX.
- Tiny footprint — 66M–99M parameters. Runs on Pi, browser, e-reader, phone.
- Stupid fast — Up to 167× real-time on consumer hardware. 4s of audio in ~25ms.
- Studio output — 44.1kHz 16-bit mono WAV, no upsampler needed.
- 31 languages — Full multilingual support with
lang="na"auto-detect fallback. - Voice cloning — Clone any voice via Voice Builder, deploy permanently offline.
- Expression tags — Only
\x3Claugh>is user-verified to produce audible expression.\x3Cbreath>and\x3Csigh>are weak/unconfirmed. All others fail silently.
Prerequisites
Requires the Python SDK and model assets. Install once:
pip install supertonic
First run auto-downloads ~400MB of ONNX models from Hugging Face into ~/.cache/supertonic3/.
Quick Use
Python SDK
from supertonic import TTS
tts = TTS(auto_download=True)
style = tts.get_voice_style(voice_name="M1")
wav, duration = tts.synthesize(
text="Your text here",
lang="en", # language code or "na" for auto-detect
voice_style=style,
total_steps=8, # quality: 5 (low) to 12 (high)
speed=1.0, # 0.7 (slow) to 2.0 (fast)
)
tts.save_audio(wav, "output.wav")
CLI (via supertonic package)
# Basic synthesis
supertonic tts "Hello world" -o output.wav
# Pick voice and quality
supertonic tts "Use a different voice." -o output.wav --voice F1 --steps 10
# Custom cloned voice
supertonic tts "Hello in my voice." -o output.wav --custom-style-path voices/my_voice.json
# Multilingual
supertonic tts "こんにちは" -o japanese.wav --lang ja
supertonic tts "Bonjour" -o french.wav --lang fr
Skill Scripts
cd ~/.openclaw/workspace/skills/supertonic-tts/scripts
source ~/.openclaw/workspace/.browser-use-venv/bin/activate
# Quick synthesis
python3 synthesize.py "Hello world" --voice M1 --output ~/hello.wav
# With expression tags (only \x3Claugh> is confirmed to work)
python3 synthesize.py "You did it \x3Claugh> I am so proud." --voice M5 --output laugh.wav
# Custom voice
python3 synthesize.py "Hello" --custom-style my_voice.json --output cloned.wav
# Japanese
python3 synthesize.py "こんにちは" --voice F3 --lang ja
# List voices
python3 list_voices.py
Voices
10 built-in voices: F1–F5 (female), M1–M5 (male).
Voice cloning: Record a short clip → upload to Voice Builder → export JSON → load with get_voice_style_from_path().
See references/voices.md for voice descriptions and Voice Builder workflow.
Expression Tags
⚠️ Mostly non-functional in practice
Supertonic accepts inline self-closing tags, but only
\x3Claugh>has been user-verified to produce a clearly audible expression (laughter burst).\x3Cbreath>and\x3Csigh>may insert minor pauses but are not confirmed as audible breathing/sighing sounds.Do not rely on tags for expression. Tested tags that failed to produce audible effect include:
\x3Csarcastic>,\x3Cexcited>,\x3Cwhisper>,\x3Cshout>,\x3Chappy>,\x3Csad>,\x3Cangry>,\x3Cchuckle>,\x3Cgiggle>,\x3Csnort>,\x3Cgasp>,\x3Cgrunt>,\x3Ccough>,\x3Cscream>,\x3Csing>,\x3Ccry>,\x3Cyawn>,\x3Chmm>,\x3Caha>.
Correct syntax (self-closing, inline):
text = "You did it \x3Claugh> I am so proud."
Reliable alternative for emotion: explicit language + speed modulation:
| Emotion | Technique |
|---|---|
| Happy | Upbeat words + speed=1.1 |
| Sad | Subdued words + speed=0.85 |
| Excited | Exclamations + speed=1.15 |
| Urgent | Short imperatives + speed=1.2 |
See references/expression-tags.md for full testing results.
Parameters
| Param | Range | Default | What It Does |
|---|---|---|---|
total_steps |
5–12 | 8 | Quality vs speed tradeoff |
speed |
0.7–2.0 | 1.0 | Speech rate multiplier |
max_chunk_length |
any | 300 | Break long text into chunks (120 for Korean) |
silence_duration |
any | 0.3 | Pause between chunks (seconds) |
lang |
ISO 639-1 or "na" |
"en" |
"na" = language-agnostic auto-detect |
verbose |
True/False | False |
Show detailed progress |
Languages
31 languages + na (language-agnostic auto-detect). See references/languages.md for all codes.
Output
- Format: 44.1kHz 16-bit mono WAV
- Returns:
(wav_array, duration_array) wav.shape=(1, num_samples)duration[0]= length in seconds
Multi-Runtime Deployment
Supertonic runs across: Python, Node.js, Browser (WebGPU), Java, C++, C#, Go, Swift, iOS, Rust, Flutter.
Scripts
scripts/synthesize.py— CLI for quick text-to-speech (supports custom voices)scripts/list_voices.py— Available voices and metadata
References
references/voices.md— Voice descriptions, selection guide, Voice Builder workflowreferences/expression-tags.md— All tags, examples, caveatsreferences/languages.md— Supported language codesreferences/deployment.md— Multi-runtime deployment options
- Make sure OpenClaw is installed (local or Docker)
- Run the install command in chat:
/install supertonic-tts - After installation, invoke the skill by name or use
/supertonic-tts - Provide required inputs per the skill's parameter spec and get structured output
What is Supertonic TTS?
On-device multilingual text-to-speech using Supertonic (Supertone). Use when the user needs local/offline TTS, voice generation, speech synthesis, or convert... It is an AI Agent Skill for Claude Code / OpenClaw, with 92 downloads so far.
How do I install Supertonic TTS?
Run "/install supertonic-tts" in the OpenClaw or Claude Code chat to install it in one step — no extra setup required.
Is Supertonic TTS free?
Yes, Supertonic TTS is completely free, licensed under MIT-0. You can download, install and use it at no cost.
Which platforms does Supertonic TTS support?
Supertonic TTS is cross-platform and runs anywhere OpenClaw / Claude Code is available (cross-platform).
Who created Supertonic TTS?
It is built and maintained by Pratyush Chauhan (@pratyushchauhan); the current version is v1.0.0.