Ever tried to interact with a machine in a modpack, only to have it not work because your hand is full? Or wanted to grab a single item but couldn't, because every hotbar slot is already taken?

Empty Hand Keybind fixes both with a single key.

Press the keybind (default: ` / grave accent (fully rebindable in Options → Controls)) and the item in your selected hotbar slot is instantly swept into the rest of your inventory, leaving your hand empty. Press it again and that same item is pulled right back into the slot it came from.

Shift + the keybind locks the currently empty hotbar slot: it stays empty even when you pick items up off the ground, so it's always ready as your "empty hand" slot. Only one slot can be locked at a time, and manually placing an item into it breaks the lock. The locked slot gets a subtle red tint so you can always see which one it is, and an action-bar message confirms when you lock/unlock it.

Why I made this

Right-clicking machines with a full hotbar. Tons of modpack blocks only respond to an empty hand, but your hotbar is always packed. Instead of shuffling items into your inventory by hand, just
tap the key, click the machine, and tap again to get your item back.
Picking things up when your hotbar is full. Want to grab a dropped item or pull something out of a container, but there's no free slot in your hand? Empty it with one keypress, there is no need to
open your inventory and rearrange everytime.

How it works

Sweeps the held stack into matching stacks first, then any free slot (hotbar before main inventory).
The second press reclaims the exact item and returns it to its original slot.
Should your whole inventory be full, it drops the item, with a slightly longer pickup delay than normal.
Shift + tap locks the selected slot empty so it survives ground pickups; shift + tap again (or placing an item in it) unlocks it.
A quick tap toggles as usual; holding the key down (e.g. for FTB Ultimine, if bound to the same key) does not trigger the toggle.

Requirements

None - other than the NeoForge Modloader

Modpacks

Feel free to use my mods in your modpack, just don't forget to give proper credit.

Other Mods by me

I run these mods together:

PAPA: Portable Aeronautics Physics Assembler - Addon for Create Aeronautics
Create: Take a seat, Piglin! - Automated Bartering - Addon for Create
Create Safe Seating - Addon for Create

Empty Hand Keybind - Hold Onto THIS