supertonic-3-mlx
================

This release is a derivative of the upstream Supertone Supertonic 3
text-to-speech model and consists of two artefact classes governed by
two different licenses:

  1. The model weights (under ./weights/*.safetensors) are released under
     the BigScience Open RAIL-M License. The full text is in ./LICENSE and
     was copied verbatim from
     https://huggingface.co/Supertone/supertonic-3/blob/main/LICENSE
     The Attachment A use restrictions (Section 5 + Attachment A clauses
     (a)–(m)) apply to all downstream use of the model and of any output
     generated by the model.

  2. The MLX port code (under ./src/supertonic_3_mlx/) is released under
     the Apache License, Version 2.0. The full text is in ./LICENSE-CODE.

Attribution and modifications statement (BigScience Open RAIL-M Section 4.c):

  Copyright (c) 2026 Supertone Inc.  — original model weights and reference
    Python/ONNX implementation. Distributed at
    https://huggingface.co/Supertone/supertonic-3
  Copyright (c) 2026 Olivier Dupont  — MLX-native port code, weight format
    conversion (ONNX → safetensors via the 3-stage extractor in
    ``src/supertonic_3_mlx/pipeline.py:_convert_onnx``), and pipeline
    optimisations (``mx.compile`` of the CFG Euler loop, cross-attention
    K/V cache shared across the 5 Euler steps). Distributed at
    https://huggingface.co/ambassadia/supertonic-3-mlx

The MLX port does not modify the model's learned parameters in any
semantic sense — the only weight-level transformation is a tensor-shape
re-layout to match the MLX memory model (e.g. depthwise Conv1d
``(C, 1, K)`` → ``(C, K, 1)``). Bit-identical audio output to the
upstream ONNX Runtime reference is preserved up to FP32 accumulation
noise (cosine ≥ 0.98 on the full pipeline, cosine = 1.00 on the vocoder).

No use of the Supertone trademarks, logos, or trade dress is asserted or
permitted by this release (BigScience Open RAIL-M Section 8).