kapynDev Tools

Jev introduces a new shape of LLM - System One, aka Decision Models

Jev is a new decision-model that outputs numeric probabilities instead of text. TypeSafe AI introduces Jev as a “System One” model that accepts text or structured data and returns floating‑point scores for yes/no, ratings, and confidence, charging only for input at $0.042 per million tokens. The lightweight API offers a cheaper, faster alternative to traditional LLMs, enabling developers to embed probabilistic decision logic directly into applications.

Simon Willison·Sep 21, 2026

Opening Kapyn…