# Jev Studio

> Jev Studio is a web workbench for Jev, the decision model by TypeSafe AI. Jev reads a text and answers typed questions (yes or no, pick one, or a position on a scale) with calibrated probabilities instead of generated words. Jev Studio is where you word those questions, prove them on labeled examples, and take them into code.

Jev (typesafe-ai/jev) is a System One decision model. It answers a fixed set of typed questions about one text in a single pass and returns a probability and a confidence for each answer. It writes no free text and gives no reasoning, and it is billed on input tokens only.

## Pages

- [Jev Studio (English)](https://jev-studio.daume.dev/): Jev Studio is a workbench for Jev, the decision model by TypeSafe AI: word yes-or-no, pick-one, and scale questions, prove them on labeled examples, and hand calibrated thresholds to your code.
- [Jev Studio (Deutsch)](https://jev-studio.daume.dev/de): Jev Studio ist die Werkbank für Jev, das Entscheidungsmodell von TypeSafe AI: Ja-Nein-, Auswahl- und Skalenfragen formulieren, an markierten Beispielen beweisen und kalibrierte Schwellen in den Code übernehmen.
- [Full text of both pages](https://jev-studio.daume.dev/llms-full.txt): every section, the comparison table, measurements, and the FAQ as Markdown

## Facts

- Built and run by Lenny Daume (https://github.com/ldaume). Invitation only; sign-in with GitHub or an invited email address.
- Question types: yes or no (noul), pick one (choice), ordered scale (score).
- Last updated: 2026-09-29