Jev

Jev is TypeSafe AI's first public model, part of a new class of "System One Models." Unlike conventional LLMs, Jev does not generate text; it makes fast, structured decisions that software can consume directly. Its outputs are type-safe and matched to a target schema, which — according to the company — yields a mathematically guaranteed zero type-error rate and no hallucinations. Every decision comes with a calibrated probability.

The model generates outputs in parallel rather than sequentially and is marketed as roughly two orders of magnitude faster and cheaper than frontier models on System One tasks (reported response time of 70–500 ms versus 3–329 s for LLMs; cost of about $0.042 per million input tokens, with output tokens free). Jev was trained with TypeSafe AI's proprietary RLCD (Reinforcement Learning for Calibrated Decisions) method and released in early access in September 2026.