Cerulean Fork
by noramibu
Cerulean Fork changes how the game checks advancements on a server, so that laggy InventoryChangeTrigger checks take less time per tick.
What it does
The mod is a fork of Icterine, which optimizes Minecraft's advancement checking system. The vanilla InventoryChangeTrigger fires whenever a container such as a chest or furnace reports a slot change, and it counts empty and filled slots alike, a habit that can strain performance when many modded advancements are loaded. Cerulean Fork keeps the same goal and adds options on top of the original.
An option lets advancements be processed only every few ticks, and another makes sure each player's first pickup of an item is always handled. Achievements Optimizer works with the original Icterine, not with this fork. The changes run on the server side, and vanilla advancements remain obtainable. Fabric API is required.
Files are published for Fabric, Forge, NeoForge and Quilt across 13 release versions, 1.21.4 – 26.3, under the GNU General Public License v3.0 or later, so the source code is open source and the issue tracker is public.
Key features
Faster trigger handling
Reported stats show InventoryChangeTrigger running about 2.5 times faster, dropping from roughly 20% of tick time to 7.5% on a test server.
Tick-based advancement batching
An option processes advancements only once every few ticks instead of on every inventory change.
Pickup handling for each player
A dedicated option makes sure the first time each player picks up an item is always processed.
Gallery
Compatibility
Latest build for each game version and loader.
26.x5 of 5 versions with builds
1.21.x8 of 8 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Large modpacks
Packs with more than 200 mods and thousands of added advancements have the most to gain from less advancement checking.
Dedicated servers
Server owners can install it alone, since clients need nothing to join.
Who it’s for: Server owners running modpacks with many modded advancements, especially those that see lag from InventoryChangeTrigger.
How it compares
Icterine is server-side only, open source under the GNU General Public License v3.0 or later, and published for 1.18.2 – 1.20.4, so it covers older versions than this fork. Heavy Core Advancement is server required with client optional, under All rights reserved, and is not open source; its files cover 1.21 – 26.1.1.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Cerulean Fork | Fabric, Forge, NeoForge and Quilt | 1.21.4 – 26.3 | Server-side only | 2026-09-15 |
| Icterine | Fabric, Forge, NeoForge and Quilt | 1.18.2 – 1.20.4 | Server-side only | 2024-02-10 |
| Heavy Core Advancement | Fabric, Forge, NeoForge and Quilt | 1.21 – 26.1.1 | Server required, client optional | 2026-04-03 |
Questions
Does Cerulean Fork require Fabric API?
Do players need to install Cerulean Fork?
Can the advancement checks be made less frequent?
Which Minecraft versions does the fork support?
In the catalog
Cerulean Fork is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 8,071 mods support Minecraft 26.3.
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What the author says
This is fork of Cerulan which is actually a fork of Icterine. Original maintainer didn't update it for a year, so i updated to modern versions as a fork of Cerulean under same name. Cerulean is a mod that optimizes Minecraft's advancement checking system, specifically the laggy InventoryChangeTrigger, which can cause…
Official listing
- Modrinth page
- modrinth.com/mod/cerulean-fork
- Owner
- noramibu
- Published
- 2026-04-07
- Updated on Modrinth
- 2026-09-15
- Facts verified
- 2026-10-15