J•JEV Field Guide

JEV / DECISION ENGINEERING

What can Jev actually decide? Follow one support ticket from message to action.

A parcel was marked delivered but is missing. Who handles it, is it urgent, and when must a person decide? Learn state, three question types, answers, and fallback through one complete case.

Start learning Jev beginner practice: design a safe decision in four steps

One support ticket runs through the course. Learn the input and questions, inspect the official API, then design a fallback using labeled examples. About 60 minutes of reading; practice time varies.

STATE→QUESTION→DECISION→CODE

INPUT / 01OUTPUT / 02

My parcel says delivered, but nothing arrived.

↘ CHOICE · support_team

shipping0.82

billing0.11

other0.07

This is a design draft, not an actual Jev answer or accuracy test.

CASE STUDY / 01

One ticket, the entire workflow

Follow one support ticket from raw text and verified facts through three questions, an illustrative answer, edge cases, and launch evaluation.

Read the worked example

01 · STATE客户说未收到 / missing parcel02 · QUESTIONSChoice + Noul + Score03 · ACTIONroute / review / gather facts

Start here

Choose your next step

Learn the boundary, make a first request, then check outcomes on examples.

Jev beginner course: from first principles to a testable workflow

Learn Jev's boundaries, state, the three question types, API answers, confidence, and validation in order. Practice before getting a key.

Your first API call

Use the official state, model, and questions structure to make a first call and inspect its answer.

Decision Design Lab

Describe a narrow task and get an editable, copyable request draft. This tool does not call Jev or validate model performance.

USE CASES

Find a use case by task

Each example separates the input, Jev's bounded decision, and the action owned by code or a person.

Support ticket routing

Choose shipping, billing, technical, or other

Model routing

Choose code, a light model, a reasoning model, or a person

RAG relevance filtering

Judge whether an excerpt supports an answer and score relevance

CURATED RESOURCES / 04

Jev learning resources: four sites mapped

Use Playground for live output, Manual for short projects, Learn Jev for patterns, and Datawhale Jev Cookbook for deeper Python and evaluation work.

Topic directory

SOURCE FIRST

Evidence and limits

We have not run a Jev API benchmark. Independent learning site. Not affiliated with TypeSafe AI.

Official docs Public cases