Knot

Mod authors who target both loaders can use Knot to write one set of code. It covers registration of blocks, items, entities and fluids through a single syntax, a networking layer for client-server packets that works across both loaders, and an event bus that gives standardized hooks over loader-specific lifecycles. The aim is to keep loader differences out of the mod's own source.

Knot is described as a thin layer, so its overhead stays small. Because it is a library, the mod itself adds no items or blocks to a world. It is required by six catalog mods, including Item Restrictions, Jobs+, GriefLogger, Tiny Mob Farm Remastered and Jobs+ Tools, which need it to function. Those mods install alongside it on the same side of the connection.

Knot runs on the client and the server, so both sides need it when a dependent mod is installed. Files exist for 1.21.1, 1.21.11, 26.1, 26.1.1, 26.1.2 and 26.2, and the latest build for both loaders is 19.2.12 for 1.21.11, published on 2026-09-15. The code is released under the GNU Lesser General Public License v3.0 only and is open source.