Capacity
A slot holds 64. What changes that number sits on the tab clipped to the left edge of the screen, and counts for the whole crate wherever inside it is placed.
The tab and its cells
The tab is not a fixed pair of slots, it is a column. The mod ships two: the top one takes a capacity module, the one below it a stack of sixteen row modules. Another mod can add more, and the tab grows with them. An empty cell shows a greyed plate, so you can see what it is waiting for.
| Module | What a slot holds | Tag |
|---|---|---|
| 128 module | 128 | deepcrate:module_128 |
| 256 module | 256 | deepcrate:module_256 |
| 512 module | 512 | deepcrate:module_512 |
A module aims at an item tag rather than a precise item, so another mod adds its own to one of these three without writing a line of code.
The best offer, not the sum
The cell an item sits in no longer decides what it does. A capacity module lifts the whole crate from any cell, and the crate keeps the strongest of the offers: two 256 modules give 256, a 256 next to a 512 gives 512. Rows follow the opposite rule and add up, which is the only difference between the two families.
Why 512 and not more
The three modules that ship stop at 512 by choice, not by limit. A slot goes up to 32,767 and a module from another mod may ask for that. The ceiling is the menu's: the current capacity reaches the client in a packet that writes a short integer, and the save file is bounded by the same number.
A slot's count travels as a variable-length integer, so a large number costs nothing on the wire. What constrains it is the game's save format, which refuses any count above 99: a crate therefore writes its slots in its own format, the item on one side and its count on the other.
Taking a module back costs whatever is over. Close the screen and anything above the new capacity drops on the floor in one tick. A full double netherite crate losing its 512 module empties 1,638 stacks at once. Empty the crate before you take the module out.