Training
Table with columns: Item, Value| Item | Value |
|---|
| Original base model | Qwen/Qwen3.5-2B |
| RL initialization | mrzhao13/qwen3.5-2b-shopsimulator-sft-512-1ep |
| RL task set | rl_500, 500 unique tasks |
| Epochs | 1 |
| Candidates per task | 4 |
| Candidates / optimizer steps | 2,000 / 100 |
| Rollout batch size / global batch size | 5 / 20 |
| Learning rate | 1e-6 |
| Advantage estimator | GRPO |
| KL loss coefficient / type | 0.001 / low_var_kl |
| Maximum model turns | 40 |
| Maximum context / response length | 16,384 / 2,048 |
| Maximum tokens per GPU | 12,288 |
| Non-zero reward-variance groups | 352 / 500 (70.4%) |
| Completed / truncated / aborted candidates | 1,881 / 119 / 0 |
| Training framework | Slime + Megatron-LM + SGLang + Pi |
| Hardware | One NVIDIA Pro 6000D 84 GB |
| Weight identity SHA-256 | 8eff796683fa32bf74af7378a64646eea190e71cb52e397de431e7da72463f18 |
Evaluation
All three checkpoints were evaluated with the same modified ShopSimulator
service, deterministic price generation, fixed official_test_200 task slice,
and one rollout per task. These are k=1 point estimates.
Table with columns: Model, Positive-reward pass@1, Strict-success pass@1, mean@1 r_loose, mean@1 r_hard| Model | Positive-reward pass@1 | Strict-success pass@1 | mean@1 r_loose | mean@1 r_hard |
|---|
| Qwen3.5-2B | 2.0% | 0.0% | 0.004286 | 0.000000 |
| SFT-512 1 epoch | 72.5% | 10.5% | 0.389829 | 0.124417 |
| This GRPO checkpoint | 90.5% | 31.0% |
The RL checkpoint also achieved a 91.5% environment completion rate and a
40.0% right-product pass@1 rate on this fixed evaluation.
Usage
Use this repository as a drop-in replacement for Qwen/Qwen3.5-2B with a
recent Transformers version that supports Qwen3.5. Refer to the
official Qwen3.5-2B model card for
loading and inference examples, replacing the model ID with this repository.
ShopSimulator evaluation requires the companion Pi extension, prompt template,
patched environment and deterministic pricing behavior from the
pi-slime-shopsimulator source repository when it is published.
Limitations
- Optimized only for Chinese ShopSimulator shopping tasks.
- Evaluated only in the patched text-based ShopSimulator environment.
- The deterministic pricing patch changes scores relative to the unpatched
upstream environment.
- The official evaluation contains 200 tasks with one stochastic rollout each.
- No visual, broad instruction-following or safety evaluation was performed.
- Online RL can amplify environment- and reward-specific behavior.
- The SFT teacher data contains AI-generated content and may contain errors.
License and attribution
The original Qwen model, the SFT initialization and these derivative weights
are distributed under Apache-2.0. The original Qwen license is included in
LICENSE. This model card identifies the checkpoint as modified and does not
grant rights to third-party ShopSimulator task or environment content.