---
license: apache-2.0
base_model: Qwen/Qwen3.5-9B
tags: [debugging, code, reinforcement-learning, gdpo, agent, precisecoder]
---
# PreciseCoder-9B-Agent

📄 [Paper (arXiv:2610.18755)](https://arxiv.org/abs/2610.18755) · 🌐 [Project page](https://precise-coder-rl.github.io/) · 💻 [Code](https://github.com/precise-coder-rl/PreciseCoder)

Qwen3.5-9B post-trained with multi-turn agentic reinforcement learning for **precise debugging**: the model
inspects buggy Python code with tools and repairs it with minimal edits (PreciseCoder project).

**Recipe.** Agentic GDPO from the base model, with two rewards weighted 2:1: unit-test pass and unit-gated F1
(edit-block F1 against the ground-truth diff). The agent loop has up to 5 turns with `view`, `str_replace_editor`
and `submit` tools. 328 steps, final checkpoint.

**Eval:**

| eval | result |
|---|---|
| PDB test, agentic (1205 BigCodeBench + LiveCodeBench debugging tasks, 5 turns) | unit 0.685 · precision 0.721 · recall 0.796 · F1 0.731 · edit lines 2.9 |

Load with `transformers` / vLLM (>=0.17) as a standard Qwen3.5 model (thinking enabled by default).

## Citation

```bibtex
@article{precisecoder,
  title   = {{PreciseCoder}: Faithful and Generalizable Debugging Beyond Unit-Test Rewards},
  author  = {Zhan, Yunkai and Chai, Miaosen and Wang, Shangshang and Zhong, Jike and Yang, Yuqing and Fu, Deqing and Chang, Serina and Zhu, Wang Bill},
  journal = {arXiv preprint arXiv:2610.18755},
  year    = {2026}
}
```