Polysit

Polysit is a server-side sit mod built on Polymer, so it needs Fabric API and Polymer on the server. It works with Fabric and Quilt, and the Quilt build also requires QSL. Players join without installing anything, because clients need nothing from the mod. Files exist for Fabric and Quilt across 29 release versions, 1.18.2 – 26.2, and snapshot builds are published.

The mod lets a player sit almost anywhere, including on cacti, and the player is immune to thorns while seated. It also moves a player out of blocks that would trap them on getting up, and forces a smaller pose so the player does not suffocate when getting off a seat. Players can use it in singleplayer or over LAN with friends, where the same functions apply without a dedicated server.

Polysit is open source under the Mozilla Public License 2.0. Its maintainers fix bugs found during development that were caused by its own functions, and aim to keep the experience close to vanilla logic. It is compatible with mods that implement standard slabs, stairs and beds, and with scale attribute mods such as Pehkui.