I've been using Jev by @typesafeai Here's the six things i've tried and am confident I'll still use Jev for 60 days from now. There's many more experiments, ideas, and things I think I will use it for. It's a big deal (more on why in next post). But I am only sharing things Show more
Answers & Confidence
Confidence
A 0-1 number on every Choice and Score answer that collapses the probability distribution into one certainty score.
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- Answers & Confidence
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- 37
- Docs
- docs.typesafe.ai
- Added
- 2026-09-24
Definition
Confidence is a statistic computed from the distribution the answer already returns: concentrated probability means a confident answer, a spread-out distribution means an uncertain one. TypeSafe returns it so you can threshold without doing the math yourself, and Noul answers do not carry one because the probability is the answer.
You are never locked into TypeSafe's definition — the full probabilities come back on every answer, so a different measure can be computed when your domain calls for one.
Tagsconfidencecore
Related terms
Definitions that connect to this one.
CalibrationThe property that outcomes given a probability of 0.2 occur about 20% of the time, measured across many predictions.Answers & ConfidenceProbability distributionThe floats summing to 1 across your options or levels that every Choice and Score answer returns under probabilities.Answers & ConfidenceConfidence gateA threshold on confidence that decides whether code acts, confirms first, or escalates to a person or a bigger model.Answers & ConfidenceConfidence floorA baseline below which code never acts on an answer, regardless of what the answer says.Answers & ConfidenceUncertaintyThe honest "I'm not sure" signal that lets a system defer instead of guessing, exposed through probabilities and confidence.Answers & Confidence
From the directory
How TypeSafe reports certainty, how it differs from probability, and how to use it architecturally to gate and route decisions.
Practices & PatternsDocs#official#confidence#routing
Official
The three TypeSafe question types, the typed answers they return, how to choose between them, and how to ask several in a single call.
Practices & PatternsDocs#official#primitives#choice
Official
A 3D robot that understands without generating text: one TypeSafe call per turn with nine typed questions, then code decides whether to act, ask, or shrug.
Cookbooks & DemosPlayground#community#playground#embodied-agent
Community
11GitHub stars
CLI that fits a per-question confidence threshold to a target accuracy on your own labeled data, verifies it on a held-out split, estimates how much traffic still needs an LLM, and re-checks locked thresholds in CI. It publishes no Jev results of its own.
Practices & Patterns#community#python#calibration
Community
abhixhek/jevcalPython
abhixhek/jevcalPython8GitHub stars
A Ruby client for TypeSafe's System One API that returns typed Noul, Choice, and Score answers, validates obvious input mistakes before spending a request, and pools HTTP connections across threads.
Repos & SDKs#community#ruby#sdk
Community
joshmn/typesafe-sdkRuby
joshmn/typesafe-sdkRuby7GitHub stars
An independent calibration study of Jev over three public benchmarks and 900 rule-generated support tickets, publishing every raw Gateway response and the quantization limits of returned probabilities.
Practices & Patterns#community#python#calibration
Community
scienthoon/jev-ood-calibrationPython
scienthoon/jev-ood-calibrationPython31 more matching entries in the full directory.
From the community
Posts from builders shipping with Jev right now.
Six uses that stuck after 60 days
Security decisions that fit Jev
This made me rethink where AI actually fits into security engineering. For purely engineering work, forget about ChatGPT or Claude. TypeSafe AI just released Jev, and I think it’s going to change how we build AI into security workflows. Instead of asking an LLM to “investigate Show more
we are officially out of stealth! join the frontier and get access to Jev on our website (link on profile)
A million judged questions
Ask Jev anything. Give it a try at askjev.ai It won't answer. It will judge. Let's see if we can get to 1 million questions. @typesafeai 🤝 @convex work great together. @hmartenjoyer @CompleteSkeptic @justKDeng @mikeysee
Inferring Jev's internals from 1,000 calls
Jevの内部アーキテクチャを推測している技術記事(Jev’s Architecture Unmasked)からメモ。 ・本記事はJevのAPIを約1万回の呼び出して、内部構造を推測したもの ・従来の言語モデルを用いた分類やルーティングでは、トークンを1文字ずつ逐次生成するために膨大な無駄な計算コストが発生していた。 Show more
The open System One roundup
Jev 发布没几天，开源社区已经开始疯狂复刻了🔥 最值得推荐的五个模型： 1、Laya 421M：原生决策模型，支持 Mac 2、Decider-2B：最像 Jev，基于 Qwen3.5 3、NanoJev 0.6B：专门的 Decision Head 4、Reflex：Qwen3.5 + Direct Logits 5、System-One 4B：专门做概率校准 Show more
Jev 刚发布没几天，开源社区就出现了同款🔥 Decider-2B模型，是基于 Qwen3.5-2B 做了特殊调整 它和 Jev 模型是一样的 只做选择 评分和判断 不是文本类的 LLM 模型 但两者还是有几个明显区别： 1、模型 Jev：闭源 System One Model Decider：Qwen3.5-2B，约 1.9B 参数，Apache 2.0 开源 2、价格
Jev lands on the Vercel AI Gateway
Jev is now available on the @vercel AI Gateway vercel.com/ai-gateway/mod…