Instinct Tuned 4B
A 4B decision model from ZooWork: a merged LoRA fine-tune of Qwen3.5-4B that reads a state and returns a probability per candidate for choice, yes/no (noul) and score questions in one forward pass, without generating text. Open weights, also on ZooWork's hosted API.
A rank-32 LoRA merged into Qwen3.5-4B, trained on about 9.4k items (data not released). The readout is over the candidate label-token logits with a temperature per question type; it needs ZooWork's reference runtime rather than generate(), transformers 5.16.1 and a CUDA BF16 GPU. Text only, 8,192-token limit, mostly English, sensitive to option order; the maker advises refitting the temperature on your own data (hard-split ECE 0.04 to 0.11 depending on option order). JevBench is a third-party benchmark; the maker's run on its public set gives 85.71%, and the maker says those items were also used for model selection, so the score is not held out. Hosted siblings with no weights of their own: instinct (frozen Qwen3.8-27B with a logit readout, training-free; maker's run 87.45%) and instinct-dual-4b (frozen Qwen3.5-4B, two option orders averaged; 82.25%). Paid API through ZooData at $0.01 per million input tokens for the 4B models and $0.03 for instinct, output free; a free preview endpoint exists. Previously skipped on 30 Sep, when the only source was a third-party issue; the maker's own repo, card and site now exist.
What it decides
- choice — picks one option from a set
- score — places the input on an ordered scale
- noul — answers a yes/no question with one probability
At a glance
| Parameters | 4B |
| Base model | Qwen/Qwen3.5-4B |
| Maker | ZooWork |
| Released | 2026-09-29 |
| License | apache-2.0 |
| Reported accuracy | 85.7% |
| Reported latency | 62 ms p50 direct upstream on one H200 (four replicas, warmed, serial); p95 about 110 ms, estimated by the maker |
Hosted API
Served by ZooWork (ZooData) — $0.01/MTok input, $0/MTok output. Get access · API docs.
Get the weights
pip install systemonemodels
systemone pull zoowork/instinct