---
language:
  - uk
  - en
license_name: lfm1.0
license_link: https://www.liquid.ai/lfm-license
tags:
  - translation
  - grpo
  - ukrainian
  - lfm2
base_model: Yehor/kulyk-uk-en
pipeline_tag: text-generation
---

# kulyk-uk-en-grpo

Ukrainian-to-English translation model based on [Yehor/kulyk-uk-en](https://huggingface.co/Yehor/kulyk-uk-en) (LFM2-350M), improved with GRPO using calibrated guardrail rewards on WikiMatrix data.

## Results

### FLoRes+ devtest (sentence-by-sentence, greedy, repetition_penalty=1.05)

| Model | BLEU | chrF | CometKiwi |
|-------|:----:|:----:|:---------:|
| kulyk-uk-en (baseline) | 36.25 | 62.54 | 0.7401 |
| **kulyk-uk-en-grpo** | **37.03** | **63.25** | **0.7436** |

### WMT24 uk-en (news domain, out-of-distribution)

| Model | BLEU | chrF | CometKiwi |
|-------|:----:|:----:|:---------:|
| kulyk-uk-en (baseline) | 27.90 | 54.49 | 0.6571 |
| **kulyk-uk-en-grpo** | **28.25** | **54.54** | **0.6598** |

## Usage

```python
from transformers import AutoModelForCausalLM, AutoTokenizer

model = AutoModelForCausalLM.from_pretrained("iamthewalrus67/kulyk-uk-en-grpo", trust_remote_code=True)
tokenizer = AutoTokenizer.from_pretrained("iamthewalrus67/kulyk-uk-en-grpo", trust_remote_code=True)

prompt = "Translate the text to English:\nПогода сьогодні чудова."
input_ids = tokenizer.apply_chat_template(
    [{"role": "user", "content": prompt}],
    add_generation_prompt=True, return_tensors="pt", tokenize=True
).to(model.device)

output = model.generate(input_ids, max_new_tokens=256, do_sample=False, repetition_penalty=1.05)
print(tokenizer.decode(output[0][input_ids.shape[1]:], skip_special_tokens=True))
```

## Training Details

- **Method**: GRPO with calibrated guardrail rewards
- **Data**: WikiMatrix uk-en (132K pairs)
- **Rewards**: chrF (0.30) + BLEU (0.25) + CometKiwi (0.20) + 5x calibrated guardrails (0.05 each)
- **Training**: Full fine-tune (no LoRA), single GPU, 300 steps
- **Best checkpoint**: step 100

See [reward-driven-translation](https://github.com/iamthewalrus67/reward-driven-translation) for full reproduction code.