Jev: The AI Model That Answers in Decisions, Not Sentences

TypeSafe’s Jev skips text generation and returns typed choices with confidence scores, in about 70 milliseconds, at $42 per billion input tokens.
artificial-intelligence
software-engineering
Author

Kabui, Charles

Published

2026-09-29

Keywords

system-one-models, calibrated-decisions, structured-outputs, model-pricing, inference-latency

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Jev is an AI model built for software rather than conversation. You send it a block of text and a short set of questions; it answers with one of the options you predefined, or a probability between 0 and 1, and never a sentence. TypeSafe AI, founded by Diogo Almeida, who worked on the training method behind ChatGPT, released it on September 15 and has since opened signups. Every question is scored in parallel against the same text, so asking five costs barely more time than asking one: 70 to 500 milliseconds per call. Pricing is $42 per billion input tokens with output free.

That buys a decision layer software can chain. A model right 95% of the time that cannot flag the other 5% cannot be left to act alone; Jev hands back a probability, so your code sets the threshold. Vercel replaced an OpenAI classifier with Jev and got results five to 18 times faster and more accurate. The 193.6x faster and 444.6x cheaper figures come from workflows TypeSafe built itself, and on its own evals Jev averages 67.8% accuracy against Opus 5’s 73.1%, at $0.0004 a case against $0.18. The weights are unpublished, and the docs list nine known failure modes, counting and arithmetic among them.

Slow reasoners that explain themselves sit alongside fast judges that return a verdict with an error bar. Jev is not an assistant you talk to; it is closer to a smarter if-statement.

Read More: GPT-5.6 Sol Ultrafast: OpenAI’s New Tier Runs 750 Tokens a Second

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Citation

BibTeX citation:
@misc{kabui2026,
  author = {{Kabui, Charles}},
  title = {Jev: {The} {AI} {Model} {That} {Answers} in {Decisions,}
    {Not} {Sentences}},
  date = {2026-09-29},
  url = {https://toknow.ai/posts/jev-system-one-model-decisions-not-sentences/},
  langid = {en-GB}
}
For attribution, please cite this work as:
Kabui, Charles. 2026. “Jev: The AI Model That Answers in Decisions, Not Sentences.” https://toknow.ai/posts/jev-system-one-model-decisions-not-sentences/.