Deterministic multiplayer

Two clients. Same inputs. Same bits.

Fast2D runs independent simulations from a shared lockstep input stream. The live world.checksum() readout proves both clients stay bit-identical until you deliberately perturb one side.

Watch it run Open benchmark
IN SYNC ✓
Tick 0
Client A checksum 0x00000000
Client B checksum 0x00000000

Click either pane to enqueue one shared spawn input for the next tick.

Shared input stream

The only thing both clients receive