---
license: apache-2.0
language:
  - eu
tags:
  - basque
  - euskara
  - capitalization
  - punctuation
  - restoration
  - onnx
  - transformers.js
  - txukun
  - quantized
  - int8
pipeline_tag: translation
---

# Txukun — Capitalization & Punctuation Restoration (ONNX)

ONNX export of [HiTZ/cap-punct-eu](https://huggingface.co/HiTZ/cap-punct-eu) for browser and edge inference with Transformers.js. Weights are dynamically quantized to int8 for faster downloads (77 MB vs 297 MB fp32).

## Model

MarianMT model trained on 9.78M Basque sentences that restores capitalization and punctuation to lowercase, punctuationless text — typically output from automatic speech recognition (ASR) systems.

**Original model**: [HiTZ/cap-punct-eu](https://huggingface.co/HiTZ/cap-punct-eu) by [HiTZ Zentroa](https://hitz.eus/) (UPV/EHU)

## Architecture

- **Type**: MarianMT (6 encoder + 6 decoder layers)
- **d_model**: 512
- **Tokenizer**: SentencePiece (Unigram, 32k vocab), shipped as custom `tokenizer.json`
- **Format**: Int8 dynamically quantized ONNX (Q/DQ nodes, compatible with ORT Web WASM)
- **Input**: Lowercase, punctuationless Basque text
- **Output**: Properly capitalized and punctuated Basque text

## Files

| File | Size | Description |
|------|------|-------------|
| `encoder_model_quantized.onnx` | 34 MB | Encoder (IR 8, int8 quantized) |
| `decoder_model_merged_quantized.onnx` | 41 MB | Decoder with KV-cache (IR 8, int8 quantized) |
| `encoder_model.onnx` | 136 MB | Encoder (fp32, for reference / non-WASM use) |
| `decoder_model_merged.onnx` | 160 MB | Decoder with KV-cache (fp32, for reference / non-WASM use) |
| `tokenizer.json` | 2.1 MB | Custom Unigram + Metaspace pre-tokenizer (for Transformers.js) |
| `source.spm` | 842 KB | SentencePiece model (for Python / HF MarianTokenizer) |
| `vocab.json` | 2.1 MB | Vocab mapping (for Python / HF MarianTokenizer) |
| `config.json` | 979 B | Model configuration |
| `tokenizer_config.json` | 864 B | Tokenizer metadata |
| `generation_config.json` | 288 B | Generation defaults |

## Usage with Transformers.js (browser)

```javascript
import { pipeline } from '@huggingface/transformers';

const corrector = await pipeline(
  'translation',
  'itzune/txukun-cap-punct-eu',
  { device: 'wasm', dtype: 'q8' }
);

const result = await corrector('kaixo zer moduz zaude');
console.log(result[0].translation_text);
// → "Kaixo, zer moduz zaude?"
```

## Usage with Python (ONNX Runtime via optimum)

Install dependencies:

```bash
pip install optimum[onnxruntime] sentencepiece
```

Basic inference:

```python
from optimum.onnxruntime import ORTModelForSeq2SeqLM
from transformers import AutoTokenizer, pipeline

model_id = "itzune/txukun-cap-punct-eu"

# Load int8 quantized ONNX model
model = ORTModelForSeq2SeqLM.from_pretrained(
    model_id,
    encoder_file_name="encoder_model_quantized.onnx",
    decoder_file_name="decoder_model_merged_quantized.onnx",
    decoder_with_past_file_name="decoder_model_merged_quantized.onnx",
    provider="CPUExecutionProvider",
    use_cache=True,
)

# Tokenizer: load from our repo or HiTZ
tokenizer = AutoTokenizer.from_pretrained("HiTZ/cap-punct-eu")

# Create pipeline
corrector = pipeline("translation", model=model, tokenizer=tokenizer, max_length=512)

# Correct text
result = corrector("euskal herrian euskaraz bizi nahi dugu")
print(result[0]["translation_text"])
# → "Euskal Herrian euskaraz bizi nahi dugu."
```

For a complete CLI tool using this model, see [txukun-cli](https://github.com/itzune/txukun-cli).

## Quantization details

Dynamically quantized with `onnxruntime.quantization.quantize_dynamic(QuantType.QInt8, extra_options={"EnableSubgraph": True})`. The `EnableSubgraph` flag traverses into the `If`-node subgraphs of the merged decoder, quantizing `MatMul` operations in both branches. Results:

- Encoder: 136 MB → 34 MB (75% reduction)
- Decoder: 160 MB → 41 MB (74% reduction)
- **Total: 297 MB → 77 MB (74% reduction)**

## Part of Txukun

This model powers [Txukun](https://github.com/itzune/txukun), a browser-based Basque text cleaning tool. Visit [itzune.eus/txukun](https://itzune.eus/txukun/) to try it.

## License

Apache 2.0 (same as original HiTZ/cap-punct-eu)