Unslotted

Within the inventory, the mod removes a portion of the fixed slots and turns that space into a freeform area. Stacks can be placed at any position there, and a single item type can be stored in unlimited amounts, which makes large collections easier to hold but also harder to sort through. A corner button pulls items back into view, and holding Shift resets positions of items that have drifted outside the visible area, so nothing is lost by dragging outside the window.

The Slotless Crate is a companion block that works like an ordinary storage container, with items moved between it and the inventory by drag and drop. The recipe places planks at the corners of a crafting grid and sticks between them. When a player dies, the crate is destroyed and its contents are dropped as an Item Cluster rather than loose items, and the Item Cluster can then be opened to retrieve them. The author reports it has been tested with gravestone mods, though compatibility with every gravestone mod is not established.

Unslotted requires Architectury API and Fabric API. It is published for Fabric and NeoForge, with both files covering 1.21.1 only, and the mod runs on the client and the server, so both sides need it. The code is released under the MIT License and is open source. The author notes that the mod changes how the player inventory stores data and suggests keeping frequent backups, since the first release is a beta.