What it is
A community-maintained Java SDK for the TypeSafe AI System One (Jev) API, for JVM developers. It provides a pure-Java core, Kotlin extensions, a Spring Boot starter, and a Spring AI bridge. Not an official TypeSafe product.
How it uses Jev
Jev answers typed questions about a piece of state. In code, you build an EvaluationRequest from state, add noul, choice, and score questions, then call client.evaluate. Results are numbers your code branches on, e.g. result.noul("is_urgent").isYes(0.7) or result.choice("department").confidenceOrZero().
Primitives:choicescorenoul
Technique worth stealing
Use Jev as a prompt-guard advisor or ChatModel in Spring AI pipelines.
Try it
Set TYPESAFE_API_KEY and use TypeSafeClient.fromEnv(); or add the Spring Boot starter and configure typesafe.* properties.
Evidence
Each line is one question put to Jev about the README. ≥ 0.60 reads as yes, ≤ 0.40 as no; in between Jev is not making a call.
- Jev-centricyes0.93
- Shows a System One patternunclear0.41
- Handles uncertaintyno0.05
- Measuredno0.04
- Runnableyes0.90
- Worth recommendingno0.23
- Model replicano0.03
- Problem scopescore on a 0–2 scale1.00
- About Jevyes0.99
Signals by Jev jev-1.13.0, card written by DeepSeek V4.1 Flash from the README on 21 Sept 2026.