SMS Swap is a lightweight client-side Fabric mod for Minecraft 1.21.4 that helps you execute fast PvP combos by swapping to a configured hotbar slot, waiting a small delay (for server sync), performing the action, then returning to your previous slot automatically.
100% client-side (no server install required)
Hit macro (always triggers):swap → delay → vanilla attack → delay → swap back
Uses the vanilla attack behavior (same as pressing LMB): works on entities, blocks, and air.
3 separate Use macros (multiple keybinds):swap → delay → vanilla use → delay → swap back
Configurable delays (ticks)
Automatic return to your previous hotbar slot
Settings persist in .minecraft/config/sms-swap.json
In-game configuration via commands + tab completion
Default bindings (change in Controls):
Use Macro 1: X
Use Macro 2: Left Alt
Use Macro 3: C
Start with delay 2
If your server has higher ping or strict anti-cheat, try delay 3–5
Settings are saved automatically to:.minecraft/config/sms-swap.json