---
base_model: Qwen/Qwen3-4B-Base
library_name: transformers
pipeline_tag: text-generation
tags:
- qwen3
- safety
- grpo
- checkpoint-bundle
---

# Qwen3-4B GRPO checkpoint bundle

This public repository contains the selected final/root GRPO checkpoints from the Qwen3 safety experiment. They were initialized from **Qwen3-4B-Base**, not from the non-Base Qwen3-4B instruct/chat model.

The bundle contains four independently loadable subdirectories:

- `grpo_qwen3_4b_base`
- `grpo_qwen3_4b_base_general`
- `grpo_qwen3_4b_midtrain`
- `grpo_qwen3_4b_midtrain_general`

Only the selected root/final model weights are included; intermediate `checkpoint-*` directories are intentionally omitted. Each subdirectory includes its model configuration and tokenizer files.

Example:

```python
from transformers import AutoTokenizer, AutoModelForCausalLM

path = "Zzyy2000/qwen3-4b-grpo-main/grpo_qwen3_4b_midtrain"
tok = AutoTokenizer.from_pretrained(path)
model = AutoModelForCausalLM.from_pretrained(path, torch_dtype="auto", device_map="auto")
```

See the handoff code repository for the training and evaluation scripts: https://github.com/ZhengyueZhao/qwen3-midtrain-handoff