A family of open System One models by Mark Marosi that softmax option-letter logits at an answer slot: decider-0.8b, 2b, 4b and 35b-a3b on Qwen3.5 bases, decider-12b on Gemma-4-12B-it, and training-free readouts of larger chat models. This page carries decider-2b v11.
A 149.6M ModernBERT-base cross-encoder with a scalar head that picks an agent's next action or tool from labels and descriptions you supply. Each option is scored against the state and a softmax ranks the set; no text is generated. Experimental preview, not calibrated.
Decides
choice, score, noul, classify, route
choice, rank, route
Architecture
decider
modernjev
Fine-tuned from
qwen/qwen3.5-2b-base
answerdotai/modernbert-base
License
apache-2.0
apache-2.0
Availability
Open weights
Open weights
Hosted by
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Input price
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Decision accuracy
75.2%
73.4%
Calibration error
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Valid action rate
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Median latency
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p95 latency
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 decider and modernjev-decide?
decider is from Mapika and modernjev-decide from Maziyar Panahi. Both have open weights you can download and run. Both answer choice and route questions. Only decider answers score, noul and classify. Only modernjev-decide answers rank. decider reads up to 32K tokens of state, against 4K tokens for modernjev-decide. modernjev-decide is the smaller model, at 150M parameters to 1.9B.
Which is more accurate, decider or modernjev-decide?
They report on different suites — decider 75.2% on Decider regression set, 28 held-out tasks (decider-2b v11), modernjev-decide 73.4% on AgentToolDecisions-180K held-out test, next action type (1,158 decisions, 3 choices; the maker's split) — so the numbers do not rank them. Test both on your own labelled examples.
Which is cheaper, decider or modernjev-decide?
decider: Free (open weights). modernjev-decide: Free (open weights). Open weights cost nothing per call beyond your own hardware.
Can I run decider or modernjev-decide locally?
Yes, both: systemone pull mapika/decider and systemone pull maziyar-panahi/modernjev-decide download the weights.
