Jev Solves an Unseen Flutter Game

Jev played an unseen Flutter game through LeanCodePl Marionette, solving five puzzles using rules shown only on screen.

View on X cost$0.0012time9.7 s

Mateusz Wojtczak 💙@matiwojt𝕏

I ran @LeanCodePl Marionette with @typesafeai Jev. One sentence: "win the game." A Flutter game it had never seen. 5 puzzles, rules only on screen. It read the code, flipped the right switches, tapped blue, red, green. 🤯 9.7 s. $0.0012. ⚡ No LLM involved. Marionette reads the widget tree and taps, Jev decides 🧵

Sep 19, 2026X postsView on X

Marionette read the widget tree and handled taps, while Jev decided what to do. It flipped the right switches and tapped blue, red, and green. The author says no LLM was involved.

Also filed under Games & real time

Benchmarks Jev on Pokémon Red
The project benchmarks Jev, TypeSafe’s fast decision model, against Jev paired with a GPT-6 Sol planner for playing Pokémon Red.
Plain-English Cellular Ecosystem Simulator
LifePot is a cellular automaton-inspired ecosystem that users describe in plain English. Jev turns those inputs into species, feeding relationships, reproduction strategies, and environmental conditions.
Mapping Children's Behavioral Intent in Games
Mores Research used Jev to map children’s behavioral intent in games and examine how it correlates with real-world behavior. It reports mapping intents across 45+ real sessions involving 20 child users over a long horizon.
StarCraft Agent for Fast Tactical Decisions
Jev_Star is a StarCraft agent experiment that uses Jev for fast tactical decisions.