Achievements Optimizer

Achievements Optimizer is a lightweight performance mod that optimizes how item-based achievements and advancements are processed — reducing unnecessary inventory scans and improving overall tick efficiency.

It doesn’t change any gameplay mechanics or logic — only makes achievement checks faster and cleaner under the hood.

⚙️ Key Optimizations - Early tick skipping — heavy slot calculations (empty/occupied/full) are skipped early, preventing extra work per event. - Instant empty stack discard — with ignoreEmptyStacks enabled, empty stacks are removed immediately without scanning the entire inventory. - Fast multi-item matching — single-pass inventory check using boolean[] flags with early exit. No allocations, noticeably faster on large inventories or long condition lists. - Early slot filtering — slots.matches(full, empty, occupied) is evaluated first, avoiding deeper checks when slots don’t match. - Preserved fast path for single targets — when items.size() == 1, the comparison is done directly on the changed slot without a full inventory pass.

🚀 Result

Fewer redundant checks, less memory churn, and faster responses to inventory events. Particularly beneficial for servers or modpacks with many players and complex advancement triggers.

From version 2. 0. 0 required Forge Config API Port (only for fabric version). Feel free to write about all problems and suggestions on my github! Good luck!