---
base_model: kenzrx/qwen3-4b-sft-merged
datasets:
- structured_data_with_cot_dataset_v2
- structured_data_with_cot_dataset_v2
language:
- en
license: apache-2.0
library_name: transformers
pipeline_tag: text-generation
tags:
- qwen
- unsloth
- transformers
- text-generation
- lora
- merged
- dpo
- alignment
- sft
---

# qwen3-4b-instruct-2507-sft-dpo-qwen-cot-merged

This repository provides **full-merged 16-bit weights** (no adapter loading required).

## What this model is
This model was trained in **two stages**:

1) **SFT (Supervised Fine-Tuning)** to learn high-quality reference answers / formatting  
2) **DPO (Direct Preference Optimization)** to align outputs toward preferred responses

### Lineage
- **Original base**: Qwen/Qwen3-4B-Instruct-2507
- **Stage 1 (SFT) output (merged)**: kenzrx/qwen3-4b-sft-merged
- **Stage 2 (DPO) output (this repo)**: merged 16-bit weights

## Training Objective (DPO)
The DPO stage optimizes the model to prefer **chosen** outputs over **rejected** outputs
given the same prompt, improving response alignment and structured quality.

## Training Configuration (DPO)
- **Start model (SFT merged)**: kenzrx/qwen3-4b-sft-merged
- **Method**: DPO (Direct Preference Optimization)
- **Epochs**: 1
- **Learning rate**: 1e-07
- **Beta**: 0.1
- **Max sequence length**: 1024
- **LoRA Config (during training)**: r=8, alpha=16 (merged into final 16-bit weights)

## Datasets
- **SFT dataset**: structured_data_with_cot_dataset_v2  
- **DPO preference dataset**: structured_data_with_cot_dataset_v2

## Usage
You can use this model directly with `transformers`.

```python
from transformers import AutoModelForCausalLM, AutoTokenizer
import torch

model_id = "your_id/your-repo-name"

tokenizer = AutoTokenizer.from_pretrained(model_id)

model = AutoModelForCausalLM.from_pretrained(
    model_id,
    torch_dtype=torch.float16,
    device_map="auto",
)

prompt = "Your question here"
messages = [
    {"role": "user", "content": prompt},
]

inputs = tokenizer.apply_chat_template(
    messages,
    tokenize=True,
    add_generation_prompt=True,
    return_tensors="pt",
).to(model.device)

outputs = model.generate(**inputs, max_new_tokens=512)
print(tokenizer.decode(outputs[0], skip_special_tokens=True))
