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.
Upstage's structured decision model, a System One endpoint on Solar Mini 4. Returns a choice, a score or a yes/no answer with a probability read from the model, in one forward pass, on the same /v1/systemone schema as Jev.
Decides
choice, score, noul, classify, route
choice, score, noul, classify, route
Architecture
kev
solar
Fine-tuned from
qwen/qwen3.5-4b-base
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License
apache-2.0
proprietary
Availability
Open weights
Hosted API
Hosted by
—
Upstage
Input price
—
$0.10/MTok
Decision accuracy
83.8%
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Calibration error
0.042
—
Valid action rate
—
—
Median latency
—
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p95 latency
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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 kev and solar-decide?
kev is from Jared Palmer and solar-decide from Upstage. kev has open weights you can download and run; solar-decide is only available as a hosted API. Both answer choice, score, noul, classify and route questions. solar-decide reads up to 512K tokens of state, against 8K tokens for kev. kev is licensed apache-2.0; solar-decide, proprietary.
Which is more accurate, kev or solar-decide?
Only kev publishes an accuracy figure (83.8% on transfer-v4 (locked, out of domain)); solar-decide does not, so there is no comparison to make without your own test.
Which is cheaper, kev or solar-decide?
kev: Free (open weights). solar-decide: $0.1 / $0 per 1M. Open weights cost nothing per call beyond your own hardware.
Can I run kev or solar-decide locally?
kev yes — systemone pull jared-palmer/kev downloads its weights. The other is only served as a hosted API.
