DemoBox

Demos are created with a command that opens a configuration dialog, and a demo can later be opened and edited to change its contents. Attaching a demo to a sign overwrites the text on that sign with a link to the demo, and players who click the sign are taken into the demo world. The recommended way to give players access is through these clickable signs, while the open command can also send a player to a demo directly. A player leaves a demo with the leave command or the plasmid game command.

Server owners control who can do what through permission nodes. Editing a demo needs the demobox.edit command, opening one needs demobox.open, and using the sign command needs demobox.sign, although clicking a sign itself requires nothing. Commands other than demobox keep the default gamemaster permission at level 2 unless specific nodes are set. Since the open command accepts a spawn position that a setup function can run against, demos with arbitrary structures in unusual dimensions can cause problems, so the author recommends more advanced setups for those cases.

The mod runs on the server only, so players join without installing anything. It requires Fabric API, and the source code and issue tracker are public. Files are published for Fabric and Quilt across five release versions: 1.20.1, 1.20.4, 1.21.1, 1.21.8 and 26.1, under the MIT License, which makes it open source. The latest Fabric file is 1.3.0+26.1 for 26.1, and the latest Quilt file is 1.2.1+mc.1.21.8 for 1.21.8.