Kev
An open family of System One models. A LoRA adapter plus a pointer head on a frozen Qwen base returns a distribution per typed question in one forward pass, serves TypeSafe's /v1/systemone contract, and ships a fitted temperature with every checkpoint.
This entry is kev-4b on Qwen3.5-4B-Base, the family's reference size; the adapter is rank 16 (33.8M parameters) and the repository holds the adapter and head, not the base weights. On the locked out-of-domain test (transfer-v4) as served it scores 83.8% with an expected calibration error of 0.042; in-distribution 87.3%. Siblings, all Apache-2.0: kev-0.8b (69.7% out of domain), kev-9b (85.2%, Brier 0.237), kev-27b on Qwen3.8-27B, and kev-8b, kev-0.6b and kev-0.5b on older bases. Serving context is 8,192 tokens; Choice and Score take up to 255 options. No Jev outputs were used in training. Model time is 36–179 ms on an L40S; Apple silicon is slow (DeltaNet kernels).
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 calibrated probability
- classify — assigns a category from a fixed taxonomy
- route — sends the input to one of several destinations
At a glance
| Parameters | 4B |
| Base model | qwen/qwen3.5-4b-base |
| Maker | Jared Palmer |
| Released | 2026-09-19 |
| License | apache-2.0 |
| Reported accuracy | 83.8% |
| Reported latency | 36–179 ms model time on L40S; ~495 ms per sample on Apple M5 |
Get the weights
pip install systemonemodels
systemone pull jared-palmer/kev
The files are served from the maker's Hugging Face repository, jaredpalmer/kev-4b, and verified against the checksums recorded here.
Read more
This page was opened by System One for Jared Palmer, who can claim the organisation and take it over at any time.