r/LLMDevs guide builds an agent harness around Jev where the model can say it can't choose
The guide frames the harness as the model only suggesting moves while the host decides, with Jev picking from a menu or declining, plus four focus modes and pinned routing.

YOUR AGENT DOESN'T NEED A SMARTER MODEL. IT NEEDS ONE THAT'S ALLOWED TO SAY "I CAN'T CHOOSE." A BUILDER ON r/LLMDevs WROTE A WHOLE HARNESS GUIDE AROUND THAT IDEA WITH JEV. the post is "How to Build Agentic Harness using Jev." no benchmarks, no launch video. just someone explaining where the model is allowed to touch things. host lays out the menu → Jev picks one → host checks it again → the result gets written down "A model can suggest the next move. The host still owns the move." - the line the whole thing hangs on honestly my favourite part is how boring the answers are. "pick this one" or "i can't choose." that's the whole vocabulary. half the agents out there would behave better with just that second option. when it picks between providers and models it can sit one out, and a route you pinned stays pinned. then comes the part people will argue about: four focus modes, inspect, implement, verify, answer, and one of them gets zero tools. it's not the one you'd pick. Jev is TypeSafe's System One model, from the company led by GPT-4 co-author Diogo Almeida. bookmark & read today ↓
This post quotes another post: “A complete guide to getting started building with Jev”