---
license: apache-2.0
base_model: OpenMOSS-Team/MOSS-Transcribe-preview-2B
library_name: mlx
tags:
  - mlx
  - asr
  - speech-to-text
  - audio
  - moss
pipeline_tag: automatic-speech-recognition
---

# MOSS-Transcribe-preview-2B — MLX conversion

MLX-weight conversion of [`OpenMOSS-Team/MOSS-Transcribe-preview-2B`](https://huggingface.co/OpenMOSS-Team/MOSS-Transcribe-preview-2B), an English speech-to-text model pairing a Qwen3-1.7B-base decoder with a Qwen3-Omni-MoE audio encoder and a gated-MLP adapter (~2.4B parameters, Apache-2.0 upstream).

Converted from the upstream bf16 safetensors by the [peacock-asr `moss-mlx-conversion` project](https://github.com/chikingsley/peacock-asr/tree/main/projects/moss-mlx-conversion).

## Variants

| Directory | Precision | Size | Notes |
| --- | --- | --- | --- |
| `MOSS-Transcribe-preview-2B-bf16/` | bf16 | 4.6 GB | Reference MLX-layout conversion; matched PyTorch transcript exactly on the LibriSpeech smoke fixture. |
| `MOSS-Transcribe-preview-2B-text-decoder-4bit-g64/` | 4-bit affine, group 64 (text decoder only) | 2.7 GB | Strongest quantized candidate in the conversion project: 2.48 RTFx on the first 20 LibriSpeech clean-test rows with no bf16 WER regression on that slice. |
| `MOSS-Transcribe-preview-2B-all-4bit-g64/` | 4-bit affine, group 64 (all weights) | 1.3 GB | Full-model 4-bit; retained as a size-optimal candidate. |

Each variant ships `config.json`, the Qwen ByteLevel tokenizer files, and the conversion/quantization reports produced by the converter.

## Validation (Apple Silicon, conversion project)

- LibriSpeech clean-test 100-row baseline: **1.80% WER**, 1.61 RTFx (MLX bf16), vs 2.01% WER on the PyTorch bf16 reference.
- Weight-load, fixture-transcription, and streamed-eval gates passed on Apple Silicon.

## Usage

**These weights are not loadable by vanilla `mlx-lm`.** MOSS-Transcribe is a multimodal audio-encoder + adapter + Qwen3-decoder architecture with no upstream mlx-lm model type. Load them with the conversion project's runtime:

```bash
git clone https://github.com/chikingsley/peacock-asr
cd peacock-asr/projects/moss-mlx-conversion
uv run moss-streaming-eval --weights <variant-dir>   # streamed LibriSpeech WER eval
```

See the project `README.md` and `docs/PROGRESS.md` for the smoke test (`moss-mlx-smoke`), the local backend (`MossTranscribeBackend.generate`), and eval harness details.

## License

Apache-2.0, matching the upstream model. If you use these weights, also cite the upstream model:

```bibtex
@misc{moss_transcribe_2025,
  title        = {{MOSS-Transcribe-preview-2B}},
  author       = {{OpenMOSS Team}},
  year         = {2025},
  howpublished = {\url{https://huggingface.co/OpenMOSS-Team/MOSS-Transcribe-preview-2B}}
}
```