jev-demo
Ordered TypeScript SDK examples teaching Jev best practices for state, question design and acting on answers.
Overview
Jev TypeScript demo is a set of numbered example scripts that teach how to use Jev with the TypeSafe TypeScript SDK. Scenarios are grouped in three parts: preparing the state (object versus string, conversation structure, giving facts rather than math, including just enough), writing questions (Noul versus Choice, when to use Score, keeping questions narrow, structured criteria, many questions in one call, extracting a value without generation), and using answers (Jev versus code making the final decision, whether to trust every answer, risk-based thresholds, combining answers).
It is aimed at developers learning the API. Results are live rather than mocked, so numbers vary slightly between runs, and the README notes that thresholds and weights are examples to be tuned on your own data. Two root files reproduce the official introduction, including a check of whether a customer message sounds frustrated.
What the decision model decides
| Type | Question | Answers |
|---|---|---|
| Yes / no | Does this customer message sound frustrated? | — |
| Other | Best-practice comparisons across Noul, Choice and Score question designs | — |
How it works
- npm ci and add a TypeSafe key to .env
- Run scenario files in numbered order
- Compare variants of state and question design on live results
- Apply the lessons on thresholds and combining answers in your own code
Strengths
- Structured curriculum from state to decision
- Live results show real behaviour
- Covers common mistakes explicitly
Caveats
- Results vary between runs
- Example thresholds are not recommendations
Getting started
`npm ci`, copy .env.example to .env with your key, then `npm run scenario 1-state/01-object-over-string/001-plain-string.ts` or `npm run demo`.At a glance
- Type
- Library
- Status
- production
- Language
- TypeScript
- Runtime
- Node 22+
- Has code
- yes
Use cases and integrations
How curated lists describe it
Worked examples of every question type against the TypeScript SDK, written to be read in order.
MrJev/awesome-jev
Frequently asked questions
What will I learn?
How to shape state, choose between Noul, Choice and Score, and turn answers into code decisions.
Are results mocked?
No, every scenario calls Jev live, so numbers vary slightly.
What do I need?
Node.js 22+, TypeSafe access and an API key.
Related projects
Server behind api.typesafe.pro, a free anonymous System One-compatible endpoint that forwards to TypeSafe on the operator's key.
ServiceproductionBrowser form for building Jev requests from pasted text without hand-writing JSON, then rerunning to see how steady the answers are.
ProjectbetaJavaScriptTerminal REPL for shaping System One requests before writing code, with lessons, a sketch editor, conversation turns and offline simulation.
ServicebetaTypeScriptNushell module for TypeSafe's System One API: pipe content in, ask noul, choice and score questions, and filter on the numbers.
ServicebetaNushellOne-page playground and test bench for Jev with TypeSafe, OpenRouter, LLM-baseline and mock backends behind one /v1/systemone contract.
ServiceprototypeTypeScriptStatic browser interface for making structured Jev decisions through the Pollinations API, with multilingual READMEs.
ServiceprototypeJavaScript