Obssidiant Smart Inventory

Obssidian Smart Inventory is a lightweight quality-of-life mod for Minecraft 1.21.1 Fabric that reduces repetitive inventory management without changing the vanilla inventory size or replacing the default interface.

When a remembered hotbar slot becomes empty, Smart Inventory can restore a compatible stack from your main inventory while leaving the rest of your hotbar untouched.

Features

• Smart Refill — automatically refills an empty remembered hotbar slot from your inventory.
• Slot Memory — remembers the item assigned to each hotbar slot.
• Prefer Fullest Stack — when multiple compatible stacks are available, the largest stack is used first.
• Hotbar Safety — replacement items are never taken from another hotbar slot.
• GUI Guard — automatic inventory movement pauses while an inventory or container screen is open.
• Exact Item Matching — renamed or component-different items are not treated as identical replacements.
• Respawn Safe — slot memory resets correctly when the player context changes.

Requirements

• Minecraft 1.21.1
• Fabric Loader
• Java 21
• Fabric API is not required

Installation

1. Install Fabric Loader for Minecraft 1.21.1.
2. Place the Obssidian Smart Inventory JAR in your mods folder.
3. Launch Minecraft.

Compatibility
This is a client-side utility mod. It does not add new inventory slots, alter world generation, or require save conversion.

Uninstallation
Remove the JAR from your mods folder.

Tested
Validated on Windows and Linux with Minecraft 1.21.1, Fabric Loader 0.19.5 and Java 21.

Author
Obssidiant-art