Voice with Guaardvark

Read setup first. Expressive voices need the audio_foundry plugin running; Piper works without it. B=${GUAARDVARK_URL:-http://localhost:5000}.

Which engine

engine	route	when
Chatterbox	Audio Foundry backend: "chatterbox"	expressive, emotion presets, cloning
Kokoro	Audio Foundry backend: "kokoro"	fast, clean, 10+ built-in voices (af_heart default)
Piper	/api/voice/text-to-speech	offline fallback, no GPU

GET $B/api/audio-foundry/voices lists what is installed. GET $B/api/voice/voices lists Piper voices.

Speak a line or a script

Over MCP, call generate_speech (text up to 3000 characters, optional voice such as af_heart, engine auto | kokoro | chatterbox); it waits and returns the file with a download link. Cloning is not offered over MCP. Without MCP, or for the Chatterbox knobs, use REST:

curl -s -X POST $B/api/audio-foundry/generate/voice -H 'Content-Type: application/json' -d '{
  "text": "The line to speak.",
  "backend": "auto",            # auto | chatterbox | kokoro
  "voice_id": "af_heart",       # Kokoro voice, or omit
  "emotion": "calm",            # Chatterbox preset, or omit
  "exaggeration": 0.5, "cfg_weight": 0.5, "temperature": 0.8,   # Chatterbox knobs, optional
  "seed": 7, "output_format": "wav", "async": true
}'

• Short text returns the file directly (path, document_id). With "async": true or long text you get 202 {"job_id"}: poll GET $B/api/audio-foundry/jobs/<job_id> until status is done; the result has path and document_id. Cancel: POST .../jobs/<job_id>/cancel.
• Multi-section narration with pauses: POST $B/api/voice/narrate {"script": "...", "engine": "kokoro", "voice": "...", "pause_between_sections": 0.6, "output_format": "wav"}.
• Piper only: POST $B/api/voice/text-to-speech {"text", "voice": "libritts"} returns audio_url.

Clone a voice (consent-gated)

1. The reference must go through the upload route; that is what records consent. Arbitrary file paths are refused with 403.

   curl -s -X POST $B/api/audio-foundry/voice-clips/upload -F file=@/abs/path/ref.wav -F name="Narrator sample"
   

   The response gives the stored path. GET $B/api/audio-foundry/voice-clips lists clips.
2. Generate with "backend": "chatterbox", "reference_clip_path": "<that path>".
3. Before uploading, ask whether the voice belongs to the user or someone who consented. Do not clone a public figure or anyone who has not agreed. Refuse politely if unclear.

Rules

• 10 to 20 seconds of clean speech is enough for a clone; more is not better.
• Say which engine ran (the response reports it); auto falls back to Kokoro on a Chatterbox error.
• Audio files are local under data/outputs/; they also appear in the Audio library page.