Jev and Laya Guides

Background reading for the case library: what Jev is, how the API and pricing work, the open-source Laya alternative, and benchmarks. Each guide is written from primary sources, then linked to the cases that use it.

• What is Jev — Jev is TypeSafe AI's System One model: typed decisions (choice, score, noul) instead of text - what it means, how it was trained
• Jev API — The Jev API: POST api.typesafe.ai/v1/systemone, model jev-latest (jev-1.13.0), Python and JS SDKs, framework integrations and
• How to use — Working Jev examples: raw HTTP, the Python client, the JavaScript SDK, Pydantic AI typed output, and how to wire a decision step
• Laya — Laya is a 421M-parameter open decision model with Jev-style choice, score and noul answers: 1-2GB RAM, GPU, ONNX, MLX and Core ML
• Laya vs Jev — Laya vs Jev: 0.766 vs 0.727 routing accuracy on the public typed-decisions benchmark, 5-35 ms local latency, and local vs hosted
• Run Laya locally — Install and run Laya locally: pip install laya, the Node ONNX runtime, Apple MLX and Core ML ports, memory needs, latency
• Laya + Core ML — Laya's Core ML port runs typed decisions on the Apple Neural Engine at about 5 ms, with published speed and energy benchmarks.
• Laya + MLX — Laya's native MLX runtime does 7-14 ms short decisions on an M3 Max, with FP16 weights and a playground. When to pick MLX over
• Jev cases — Where decision models beat chat models: routing, triage, guardrails, eval grading, moderation, trading bots and browser agents
• Agent phone MCP — sv-number is an MCP server that gives an agent nine phone tools: order a private number, wait for the SMS code, cancel or finish
• Projects — The Jev and Laya open-source ecosystem on GitHub: Apple-silicon runtimes, awesome lists, benchmark distills and agent
• Benchmarks — Jev vs Laya published numbers: 0.727 vs 0.766 routing accuracy, Brier and ECE calibration, latency on GPU, MLX and Core ML, all
• FAQ — Short answers on Jev and Laya: what they are, who made them, pricing, hallucination, running locally, model versions and

Or jump straight in: all 1173 Jev cases · use-case topics · builders

Last updated: 2026-09-22 · sources & corrections · every card links to its author's original post