Jev introduces a new shape of LLM - System One, aka Decision Models
Simon Willison’s Weblog 3 weeks ago 35 ● 19 sources
TypeSafe AI introduced Jev, a System One (decision model) that takes text or structured state inputs and returns category scores, yes/no probabilities, ratings, and confidence values rather than text. Jev’s first model is priced at $0.042 per million input tokens, with output free. This shifts developers toward classification-style uses and makes large-scale experiments and evaluation more important because the responses provide numeric outputs without explaining underlying signals.