HopperLock is a lightweight Minecraft plugin that makes hopper-based item filters simpler and more compact.

Instead of relying on complicated redstone filter setups, HopperLock allows you to lock items directly inside a hopper. When a hopper is locked, one item will always remain in each occupied slot, while any excess items can continue to flow through the hopper normally.

For example, a locked hopper containing:

Iron ×32 | Gold ×16 | Diamond ×8 | Redstone ×20 | Coal ×64

will continue transferring items until it reaches:

Iron ×1 | Gold ×1 | Diamond ×1 | Redstone ×1 | Coal ×1

The final item in each locked slot is preserved, allowing the hopper to remember which items belong in each slot and making it ideal for building simple, compact item sorting systems.

Features

Lock hopper slots with a simple command
Keeps 1 item in every occupied slot
Excess items continue transferring normally
Empty slots remain unrestricted
Locks persist across server restarts
Designed for compact item filtering systems
Lightweight and easy to use

Simply fill the hopper with the items you want to reserve, look at the hopper, and use /hopperlock.