AI Fundamentals8 min
What Is a System One Model? Jev and the Shift to Typed AI Decisions
Jev, released by TypeSafe in September 2026, is the first System One model: you hand it state and typed questions, and it answers them without writing a word of prose. What the category is, what “cannot hallucinate” actually guarantees, and why a typed decision is a content-modelling problem first.
Read guide