openclaw/smallest-ai

Smallest AI — Ultra-Fast Voice Suite

Text-to-speech (sub-100ms) via Lightning v3.1 and speech-to-text (64ms TTFT) via Pulse.

Setup

1. Get API key from https://waves.smallest.ai → click "API Key" in left panel
2. Set SMALLEST_API_KEY in your environment:

export SMALLEST_API_KEY="your_key_here"

Defaults

• Default female voice: sophia (American English)
• Default male voice: robert (American English)
• Default language: en
• Default speed: 1.0
• Default sample rate: 24000

Voice Selection Rules

Follow these rules to select the voice:

1. If user explicitly names a voice (e.g. "use advika"), use that voice.
2. If user asks for a male voice, use the configured defaultVoiceMale.
3. If user asks for a female voice, use the configured defaultVoiceFemale.
4. If no gender preference, use defaultVoiceFemale (sophia by default).
5. For Hindi content: use advika (female) or vivaan (male).
6. For Spanish content: use camilla (female) or carlos (male).
7. For Tamil content: use anitha (female) or raju (male).

Always pass the configured defaultLanguage, defaultSpeed, and defaultSampleRate as --lang, --speed, and --rate flags unless the user overrides them.

Text-to-Speech

Generate speech audio from text using Lightning v3.1 model.

Shell (preferred — zero dependencies)

{baseDir}/scripts/tts.sh "Text to speak" --voice sophia --rate 24000 --speed 1.0 --lang en

Python (requires pip install smallestai or just requests)

python3 {baseDir}/scripts/tts.py "Text to speak" --voice sophia --speed 1.0 --lang en --out speech.wav

Voices

| Voice | Gender | Accent | Best For | |-----------|--------|-----------------|-----------------------------| | sophia | Female | American | General use (default) | | robert | Male | American | Professional, reports (default) | | advika | Female | Indian | Hindi content, code-switch | | vivaan | Male | Indian | Bilingual English/Hindi | | camilla | Female | Mexican/Latin | Spanish content | | zara | Female | American | Conversational | | melody | Female | American | Storytelling, greetings | | arjun | Male | Indian | English/Hindi bilingual | | stella | Female | American | Expressive, warm |

80+ more voices available. List all with: {baseDir}/scripts/voices.sh

Options

• --voice <id>: Voice identifier (default: sophia)
• --rate <hz>: Sample rate — 8000 | 16000 | 24000 | 44100 (default: 24000)
• --speed <n>: Playback speed 0.5–2.0 (default: 1.0)
• --lang <code>: Language code (default: en). See {baseDir}/references/languages.md
• --out <path>: Output file (default: auto-named media/tts_<timestamp>.wav)

Output

Scripts print MEDIA: <filepath> on success. OpenClaw sends this as an audio attachment.

Multilingual

Supports 30+ languages. Pass --lang with ISO code:

{baseDir}/scripts/tts.sh "नमस्ते, कैसे हैं आप?" --voice advika --lang hi
{baseDir}/scripts/tts.sh "Bonjour le monde" --voice sophia --lang fr
{baseDir}/scripts/tts.sh "Hola, buenos días" --voice camilla --lang es

Code-switching (mixing languages) works automatically — no flag needed:

{baseDir}/scripts/tts.sh "Hey, मुझे meeting remind कर दो" --voice advika --lang hi

Speech-to-Text

Transcribe audio files using Pulse model. Supports WAV, MP3, OGG, FLAC.

Shell

{baseDir}/scripts/stt.sh /path/to/audio.wav
{baseDir}/scripts/stt.sh /path/to/audio.wav --diarize --timestamps --emotions

Python

python3 {baseDir}/scripts/stt.py /path/to/audio.wav --diarize --timestamps --lang en

Options

• --lang <code>: Language (default: en)
• --diarize: Identify different speakers
• --timestamps: Word-level timing
• --emotions: Detect emotional tone

Output

Returns JSON with transcription field. With --diarize, includes speaker labels per word.

When to Use

Trigger this skill when the user:

• Asks to "say", "speak", "read aloud", or "generate speech/audio"
• Wants a "voice message", "voice note", or "audio file"
• Asks to "transcribe", "convert speech/audio to text"
• Mentions "Smallest AI", "Lightning TTS", or "Pulse STT"
• Needs fast or low-latency speech generation
• Wants Hindi, Spanish, multilingual, or code-switched voice output
• Asks to compare TTS providers or benchmark latency

Error Handling

• Missing API key → tell user to set SMALLEST_API_KEY
• HTTP 401 → invalid or expired API key
• HTTP 429 → rate limited, wait and retry
• HTTP 400 → check text length (max ~5000 chars per request). Split long text into chunks.
• Empty audio → verify voice_id is valid

Limits

• Max text per request: ~5000 characters
• For longer text: split into sentences, synthesize each, concatenate with sox or ffmpeg
• Free tier: 30 minutes/month of TTS
• Basic ($5/mo): 3 hours of TTS + 1 voice clone