Fatfingert

Fatfingert lets you reserve specific hotbar slots and the offhand slot for specific items. If an input would put the wrong item into a slot you’ve reserved, that single input is cancelled and nothing else happens. This covers the moments that could potentially cost you, like:

• Pressing F to swap hands and grabbing back the wrong item, or
• Shift-clicking a chest and having a reserved hotbar slot get filled with junk
• Fatfingering (haha u see where the name comes from???) something into the slot your totem or shield is supposed to live in

It catches all of this before it happens, in any inventory screen. Whether it’s your own inventory, chests, shulker boxes, anywhere.

Rules are organized into presets, so you can keep different setups for different situations and switch between them with one click. A preset for reserving your offhand for a totem of undying is included by default, and a “none” preset gives you stock behavior. You can create, rename, and delete your own presets from the in-game menu (no config editing required, though the config file is plain, readable JSON if you’d rather edit it by hand).

Everything is controlled through a menu opened from a button in your inventory screen, or from Mod Menu if you have it installed (optional, not required). From there you can turn the mod on or off, switch presets, choose which slots are reserved and for which items, and toggle two extra behaviors:

• Strict Shift-Click, which also blocks shift-clicks that could land an item in a reserved slot
• Lock Contents, which stops a reserved item from being taken back out of its slot at all.

Fatfingert is client-side only and does not need to be installed on a server. It does not automate, inject, or send any input on your behalf. It only ever cancels an input. It does not read or send any data anywhere. All settings are saved to a local config file in your own game folder.

Using Fatfingert
Fatfingert requires Fabric API and Fabric Loader to be installed, and targets Minecraft 26.1.2.

The downloaded jar file should be placed in your mods folder.