Introducing System One Models & Jev
Diogo Almeida’s launch post, 15 September 2026. The names, the training claim (RLCD), the speed and price figures, and the comparison with chat models.
Introduction
The short version: state and typed questions in, structured answers out.
System One
What the model class is for, and how it differs from a language model. Text in. No images yet.
Primitives
How to choose Noul, Choice, or Score, and how to ask several at once. The pages for Noul, Choice, and Score have the response fields.
Confidence
How confidence is derived from a distribution, and how to use it as the line between acting and escalating.
State
What to send as context, and how a question points at a nested field.
How to build with System One
Keep the workflow in code. Give the model narrow judgments.
Jev 1.13 jaggedness
TypeSafe’s own list of rough edges on the current model. Worth reading before you trust a new question shape.

These four are the ones that change how you design the call. The patterns index and the cookbooks go further.

Speculative fan-out. Ask every question you might need, including ones some inputs will ignore.
Confidence-gated routing. The answer says what. Confidence says whether to act.
Composite scoring. Split one vague rating into atomic scores and weight them yourself.
Intent routing. Send a request to code, to a specialist model, or to a person.

Laravel AI SDK
What this site uses. Boolean, choice, and score classifications. A boolean is the Noul question under Laravel’s name.
TypeSafe JavaScript SDK
The official client. noul(), choice(), and score(). The snippets on the Demo page follow it.
TypeSafe Python SDK
The same questions as Python objects, synchronous or asynchronous.
HTTP API
POST /v1/systemone. The model field selects Jev. The docs’ examples use jev-latest.
Jev on OpenRouter
How to call ~typesafe/jev-latest with an OpenRouter key. That is the path this site takes when a key is set. OpenRouter bills the account.

Demo
Three questions, recorded answers on the public site, live answers when you bring a key.
github.com/tibor-src/jev-site
The Laravel app behind these pages.
tibor.io
The person who published the site.

Jev - A Decision Model

Resources