kittensynth

KittenTTS synthesis layer built on kitteng2p + OnnxVoice.

This MVP follows the same repository/package shape as PiperSynth/PiperG2P:

pyproject.toml
kittensynth/
tests/
docs/

There is no src/ layer and no hard-coded package version.

Architecture

prepared speakable English
        |
        v
kitteng2p
  - eSpeak
  - Kitten phoneme tokenization
  - Kitten v0.8 token IDs
        |
        v
kittensynth
  - voice alias/style row
  - speed-prior policy
        |
        v
onnxvoice
  - catalogs/install/cache/integrity
  - ORT providers/sessions
  - Kitten graph ABI
        |
        v
float32 waveform

kittensynth has no direct eSpeak or phonemizer dependency. That is now entirely owned by kitteng2p.

Required OnnxVoice contract

A future/updated OnnxVoice release must register:

system = kitten

and expose:

runtime.infer(token_ids, style=style, speed=effective_speed)

The installation contains at least:

role=model
role=voices

with 24 kHz metadata and Kitten voice aliases/speed priors.

Managed model

from kittensynth import KittenVoice

with KittenVoice.from_pretrained("nano-0.8-int8") as model:
    result = model.synthesize_prepared(
        "Hello from KittenSynth.",
        voice="Jasper",
    )
    result.save_wav("hello.wav")

Local model

from kittensynth import KittenVoice

with KittenVoice.from_local(
    model_path="kitten_tts_nano_v0_8.onnx",
    voices_path="voices.npz",
    config_path="config.json",
) as model:
    result = model.synthesize_prepared("Local synthesis.", voice="Bella")
    result.save_wav("local.wav")

Prepared-text boundary

Like PiperG2P/PiperSynth, this MVP expects prepared speakable text. Written-form semantic expansion (numbers, currencies, dates, URLs, abbreviations) stays outside the engine.

That keeps these packages independent:

semantic preparation -> kitteng2p -> kittensynth -> onnxvoice

Voice selection

The current v0.8 aliases are:

Bella   -> expr-voice-2-f
Jasper  -> expr-voice-2-m
Luna    -> expr-voice-3-f
Bruno   -> expr-voice-3-m
Rosie   -> expr-voice-4-f
Hugo    -> expr-voice-4-m
Kiki    -> expr-voice-5-f
Leo     -> expr-voice-5-m

The style row is selected exactly as upstream v0.8:

min(len(text), style_rows - 1)

Dynamic versioning

Both kitteng2p and kittensynth use the same Git-tag-driven setuptools-scm pattern:

git tag v0.1.0
python -m build

The source-ZIP fallback is 0.1.dev0; installed __version__ comes from distribution metadata.

Development

For sibling checkout development:

python -m pip install -e ../kitteng2p
python -m pip install -e ".[dev]"
python -m pytest

Real synthesis remains blocked until OnnxVoice contains the Kitten adapter/catalog parser.