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OpenJevSwift

Native Swift port of OpenJev: a Jev-compatible /v1/systemone server on Apple Silicon Macs and libraries for on-device iPhone decisions.

Servicebeta
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Overview

OpenJevSwift is a native Swift implementation of the razorback16 OpenJev decision server. You ask a model typed questions about text (noul, choice, score) and get probabilities read from the model rather than generated text. A single openjev binary serves DiffusionGemma 26B-A4B or JevK5 on MLX, or Verdict or Laya on Core ML, on Apple Silicon Macs with upstream's exact wire API, so TypeSafe's SDKs work unchanged. The same Swift libraries answer requests inside iPhone or Mac apps, and a demo app answers as you type.

Per the list summary, the Core ML ports matched upstream's top answer on all 666 compared items, and CI runs TypeSafe's Python and TypeScript SDKs against it. It requires macOS 15 and Xcode 27 (with notes for older Xcode), downloads converted model packages on first start (about 310 MB for Verdict), and has documentation in several languages. It suits Swift developers wanting on-device decisions and Mac users wanting one native binary instead of a Python stack.

What the decision model decides

TypeQuestionAnswers
Yes / noProbability of yes for a question about the textyes · no
ChoiceWhich option fits, with a probability for each—
ScoreHow much on a scale—

How it works

  1. Build the openjev binary with Swift.
  2. Serve a backend such as Verdict, Laya, DiffusionGemma or JevK5.
  3. Call /v1/systemone with TypeSafe SDKs, or use the Swift libraries in an app.
  4. Act on probabilities on device.

Strengths

  • On-device decisions on iPhone and Mac.
  • Wire-compatible with TypeSafe SDKs, tested in CI.
  • Single native binary.

Caveats

  • Requires recent macOS and Xcode.
  • Large models need MLX and ample memory.

Getting started

xcodebuild -downloadComponent MetalToolchain; git clone https://github.com/Algorythm-Canada/OpenJevSwift.git; cd OpenJevSwift; swift build -c release --product openjev; .build/release/openjev serve --backend verdict

At a glance

Type
Service
Status
beta
Language
Swift
Runtime
macOS server, iOS library
Has code
yes
Has tests
yes

Use cases and integrations

How curated lists describe it

  • Local runtime: native Swift port of OpenJev that answers `Choice`, `Score` and `Noul` questions behind a Jev-compatible `POST /v1/systemone` endpoint on Apple silicon Macs (DiffusionGemma and JevK5 on MLX; Verdict and Laya on Core ML, with upstream's top answer on all 666 compared items) and inside iPhone apps through its Swift libraries, with a CI job that runs TypeSafe's Python and TypeScript SDKs against it unchanged.

    yibie/awesome-jev

  • Native Swift port of [OpenJev](https://github.com/razorback16/openjev): a Jev-compatible `/v1/systemone` server for Apple silicon Macs (Verdict and Laya on Core ML, DiffusionGemma and JevK5 on MLX) whose libraries also answer Choice, Score and Noul questions inside iPhone apps.

    cobanov/awesome-jev

  • Native Swift implementation of OpenJev: Jev-compatible System One typed decisions (noul, choice, score) on Apple silicon. Research and planning phase.

    hellogumbo/awesome-jev

  • Native Swift implementation of the OpenJev typed-decision server: yes/no, choice and score answers on Apple platforms, with a triage demo app.

    MrJev/awesome-jev

Frequently asked questions

Can I use it inside an iPhone app?

Yes, its Swift libraries answer decision requests on device.

Do TypeSafe SDKs work with it?

Yes, it implements upstream OpenJev's exact wire API and CI tests the SDKs.

Which models can it serve?

DiffusionGemma 26B-A4B and JevK5 on MLX, Verdict and Laya on Core ML.

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