10/03/2026
𝗝𝗘𝗩 𝘀𝘁𝗮𝗿𝘁𝗲𝗱 𝗮 𝗰𝗹𝗮𝘀𝘀 𝗼𝗳 𝗺𝗼𝗱𝗲𝗹𝘀. 𝗢𝗽𝗲𝗻 𝘀𝗼𝘂𝗿𝗰𝗲 𝗺𝗮𝘁𝗰𝗵𝗲𝗱 𝗶𝘁 𝗶𝗻 𝗮 𝗺𝗼𝗻𝘁𝗵.
TypeSafe calls the class "System One," after Kahneman's fast, intuitive thinking. These models don't generate text. They make typed decisions — classify, yes/no, score — in a single forward pass, and return calibrated probabilities with them.
𝗧𝗵𝗲 𝗼𝗽𝗲𝗻-𝘀𝗼𝘂𝗿𝗰𝗲 𝘀𝗶𝗱𝗲 𝗶𝘀 𝗮𝗹𝗿𝗲𝗮𝗱𝘆 𝗰𝗼𝗺𝗽𝗲𝘁𝗶𝘁𝗶𝘃𝗲:
nimble (9B, Bespoke Labs) — within a point of JEV on the public decision benchmarks
tev1 (4B / 0.8B, Together AI)
clef:27b (Cloudflare) — the most tightly calibrated of the three, and the only one with vision
Ollama 0.35 added native support via a /v1/systemone endpoint. All of it runs locally, 70 to 500 ms per decision.
I open-sourced a Python client for it. Two reasons: the official Ollama Python client didn't support the decision endpoint yet, and I wanted a clean fallback mechanism.
𝗪𝗵𝗮𝘁'𝘀 𝗶𝗻 𝗶𝘁:
systemone() — one call, three question types (yes/no, multi-choice, rubric score)
systemone_fallback() — fast small model first, escalate to clef:27b only when confidence drops
runnable examples that exercise the available Ollama models — example.py covers all three question types, example_image.py covers vision
https://github.com/designcomputer/systemone-client
The fallback is the part I'd point at. The small model answers, and only when its own confidence drops does the request go to the big one. You pay the 27B cost on the hard cases, not on all of them. That's the whole point of calibrated probabilities — they're not a nicety, they're a routing signal.
The way to learn what a decision model can do is to put one in a project you already maintain. They fit anywhere a fast, cheap, typed judgment with a confidence signal is the actual requirement — triage, routing, moderation, scoring, validation, labeling, tool selection for an agent. The public benchmarks tell you the average. Your own data tells you where the confidence holds and where it doesn't. That's the part you can only learn by running it.
Python client for the Ollama System One decision endpoint - designcomputer/systemone-client