Should I call evaluate directly or build a request?

Use evaluate with state and primitives for a one-off call. Build a JevRequest when you assemble primitives conditionally in one place, execute in another, or reuse the same request across calls.

What happens with duplicate or missing primitives?

Build throws JevValidationException when no primitives were added or when two primitives share a name, so misassembled requests fail before any network call.

How does gateway mode change model selection?

Enable gateway mode with a gateway key and the model id defaults to typesafe-ai/jev, overridable via gatewayModel. In that mode the client model is always used as a header and per-request model settings are ignored.

How do I add jev-java to a build?

It is published on Maven Central as io.github.olti1947:jev-java:2.0.0, so add that Maven dependency or the Gradle implementation line. It targets Java 17 or later.

How does a JevRequest builder validate a request?

builder() defaults the model to jev-latest, and build() throws JevValidationException if no primitives were added or if two primitives share a name, so the mistake surfaces before anything is sent.

Does Jev Java support asynchronous evaluation?

Yes. The client offers both a synchronous evaluate and a CompletableFuture evaluateAsync against the same JevRequest shape, so you can build a request in one place and execute it either way.

CommunityJev Repos & SDKs

Jev Java — Olti1947

Q: Will structured rubrics break existing string code?

No. Everywhere a primitive takes a string it also accepts a structured value, plain strings keep working exactly as before, and any Map or List works alongside Rubric and ScoreLevel helpers.

Idiomatic Java 17 and later client for Jev with one-off evaluate calls, reusable JevRequest builders, async support, and structured rubric helpers.

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Stars: 6
Language: Java
Published by: Community
Author: Olti1947
Last verified: Oct 2026

Olti1947/jev-java

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Idiomatic Java SDK for TypeSafe AI Jev System One decision engine

Forks: 3
Last pushed: Updated Sep 2026

Repo stats from the GitHub API, cached Oct 2026.

This is one of several Jev listings for the same project. The canonical entry is Jev Java — gudcks0305.

About this project

Idiomatic Java 17+ client library for TypeSafe AI's Jev System One decision engine. Everywhere a primitive takes a string, it also accepts a structured value. Plain strings keep working exactly as before; use structured values when you need to give Jev richer context. See the advanced primitives docs.

Quoted from the project's README. Read the full README.

Tagscommunity jevbest catalog-import awesomejev

Works forJev for Classification

Used inJev for Software & DevTools

Languages: Java

Highlights

Plain-string constructors keep working; maps, lists, Rubric, and ScoreLevel add richer instruction context.
Builder defaults model to jev-latest and rejects empty or duplicate-named primitive sets with validation errors.
Supports synchronous evaluate and CompletableFuture evaluateAsync against the same request shape.
Optional Vercel AI Gateway mode uses a gateway key and model header while keeping the question API unchanged.

Watch out

Install via Maven Central as io.github.olti1947 jev-java version 2.0.0. In gateway mode the client gateway model is sent as a header and a request-level model is only respected outside gateway mode. Copy reviewed against the repository README on 2026-10-04, not from running it.

Questions about this entry

Short answers drawn from the linked project or page.

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jev-sdk-java

An unofficial Java 21 client for the Jev decision API that replaces maps with records and sealed types, so a malformed choice, score or noul question fails to compile instead of coming back as a 422.