We Rebuilt Jev's API on an Open Model and Used It to Play Doom

Researchers rebuilt Jev's API using an open base model (Gemma4) to replicate TypeSafe's System One Model design, which performs zero-shot classification for fast decisions. They demonstrated the replica playing Doom and Flappy Bird with 100-124ms latency per decision, validating that open models can match Jev's published performance without needing TypeSafe's proprietary training methods.