redstonepedia

Engineer Minecraft redstone against the real game code: a headless Minecraft 26.3 simulator that runs the game’s own server classes, one game tick at a time, hundreds of sandboxes per machine, plus the tools built on it. Its first project: the 3x3 piston door with the fewest blocks, built from first principles by a night of agents.

• Real mechanics. Nothing is re-implemented: pistons, redstone dust, observers and block update order are vanilla, and every record behaves identically, tick for tick, in the unmodified official server.
• Tick by tick. Nothing advances unless asked: place blocks, flip a lever, step one tick, read every block back.
• Many at once. Each simulation is an isolated sandbox (its own level, clock and random); one JVM hosts many sandboxes, a pool runs one JVM per core.
• Readable source. Minecraft ships unobfuscated since 26.1; mctas src decompiles it so mechanics are checked in the code instead of folklore.

The smallest 3x3 piston door

A door’s size is its volume, as the piston door community counts it (vjeux, 2026-10-18: the bounding box of the build over every state of a cycle, the lever…