Ultra-small English encoders (17M, 68M and 395M) fine-tuned from Ettin rerankers. Each answers choice, noul and score questions with a probability per candidate and no generated text. Experimental v0 by one developer; the weights have no licence assigned yet.
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.
Decides
choice, noul, score
choice, score, noul, classify, route
Architecture
bekko
kev
Fine-tuned from
cross-encoder/ettin-reranker-400m-v1
qwen/qwen3.5-4b-base
License
Unassigned: the weights licence is not finalised (treated as non-commercial); training code MIT
apache-2.0
Availability
Open weights
Open weights
Hosted by
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Input price
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Decision accuracy
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83.8%
Calibration error
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0.042
Valid action rate
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Median latency
5 ms
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p95 latency
5.4 ms
Figures are from each model’s manifest; accuracy and latency are what the publishers report, on their own suites and hardware. Add a third model.
Questions
What is the difference between bekko-system-one and kev?
bekko-system-one is from Yuichi Tateno (hotchpotch) and kev from Jared Palmer. Both have open weights you can download and run. Both answer choice, noul and score questions. Only kev answers classify and route. bekko-system-one is the smaller model, at 395M parameters to 4.0B. bekko-system-one is licensed other; kev, apache-2.0.
Which is more accurate, bekko-system-one or kev?
Only kev publishes an accuracy figure (83.8% on transfer-v4 (locked, out of domain)); bekko-system-one does not, so there is no comparison to make without your own test.
Which is cheaper, bekko-system-one or kev?
bekko-system-one: Free (open weights). kev: Free (open weights). Open weights cost nothing per call beyond your own hardware.
Can I run bekko-system-one or kev locally?
Yes, both: systemone pull hotchpotch/bekko-system-one and systemone pull jared-palmer/kev download the weights.
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Evaluation suite
The maker's short-input speed probe (4-option Choice, RTX 5090, 1 Oct 2026)
