Async Advancement Toast

Async Advancement Toast

Ever unlocked a bunch of achievements at once and watched the game freeze for
a moment? This mod fixes that. It moves the work of preparing achievement
toasts off the main render thread, so the game stays smooth even when several
toasts pop up at the same time.

Client-side only. Works on Fabric, Forge, and NeoForge. No config needed.

Why you might want this

When you unlock an advancement, the game builds and renders the toast right
on the render thread — the same thread that draws every frame. Loading the
icon texture and preparing the toast content causes a visible stutter at the
exact moment the toast appears. It gets worse when multiple achievements fire
at once, like when a quest mod grants several rewards in the same tick.

How it works

Instead of letting each toast pile onto the render thread the moment it’s
earned, the mod intercepts the toast-adding call and hands the toast to a
background thread. That thread paces the release — at most two toasts every
50 ms — and posts each one back to the main thread for display. A burst of
toasts gets spread out over time instead of all landing on the same frame.

If anything goes wrong (the game version isn’t recognized, a class can’t be
found), the mod silently steps aside and the game behaves exactly like
vanilla. No toasts are lost, no crashes.

Install

1. Install Fabric, Forge, or NeoForge for your Minecraft version.
2. Put the jar file in your mods folder.
3. Launch the game. Nothing else to configure.

Classic Forge users: you also need MixinBooter
installed, since classic Forge doesn’t ship with a Mixin loader.

Compatibility

Tested on Minecraft 1.18 through 26.2 across Fabric, Forge, and NeoForge.
If the mod can’t hook into your specific version, it disables itself
quietly — the game runs as if the mod weren’t there.

Limitations

• A toast may appear up to ~50 ms later than it normally would. You won’t
  notice this.
• The toast icon still loads on the render thread the first time it’s shown
  (that’s a Minecraft limitation), but the spike no longer happens on the
  frame where you earned the achievement.
• Classic Forge needs MixinBooter; without it the mod does nothing.