2026
ukiyo
Agent-native game engine in C#. Your coding agent reads and changes the running game through skills and MCP; you watch and edit in the Studio.
ukiyo is a game engine built for coding agents first. Scenes, entities and components are plain C#, so there is no hidden editor state: what a person or an agent writes is exactly what runs.
The agent connects through skills and MCP and works on the game while it runs: pause, step, capture the real GPU frame, inject input, patch the scene and rewind. The Studio is the human window to watch, inspect, edit and take over at any point.
The same program runs on wgpu/Metal, in the browser through WebAssembly and three.js, on the CPU and headless, with bit-for-bit identical simulation. Desktop exports are a single native executable. Pre-alpha, MIT licensed.