Shared animation tools
Smooth model and creature animation helpers used by several creature mods.
Citadel Mod is a lightweight Minecraft library built to support advanced entity animations, custom models, and detailed entity properties. It provides the technical framework required by many creature-focused mods, helping them deliver smoother animations, reliable behavior, and more complex in-game features.

Citadel Mod does not add one big feature. It is a library: a toolbox of shared code that other mods call on. AlexModGuy, also known as Alexthe666, built it for his own creature and cave mods, and other authors adopted it.
You install it once and several mods use it. That keeps jar files smaller and behavior consistent. If a mod page says "requires Citadel", this is the file it means.
The official project covers Forge and NeoForge from Minecraft 1.16.5 to 1.21.1. Newer or unusual setups, such as Citadel mod Fabric, are covered honestly further down.

Smooth model and creature animation helpers used by several creature mods.
One common way to store settings and keep client and server matching.
It runs quietly. You will rarely notice it, only the mods built on it.
Works in single player and on dedicated servers.
Official builds for both loaders on the supported versions.
Free on CurseForge and Modrinth, made by AlexModGuy.
When the game starts, your mods ask Citadel for the shared tools they need. If layer 2 is missing, layer 3 has nothing to stand on, so Minecraft stops with a missing dependency message.
| You are | You need Citadel for |
|---|---|
| A solo player | Alex's Mobs, Alex's Caves or Ice and Fire |
| A server admin | Matching builds on server and players |
| A modpack maker | One shared dependency across many mods |
| A mod developer | Reusing animation and sync code |
| Citadel | GeckoLib | Bundled code | |
|---|---|---|---|
| Purpose | Shared library for AlexModGuy mods | General animation library | Copied into each mod |
| Separate install | Yes | Yes | No |
| Loaders | Forge, NeoForge | Several | Varies |
| Replaceable | No, mods name it | No, mods name it | n/a |
Libraries are not interchangeable. Install the one your mod lists.
"Install Citadel first, then the mod that asks for it. The crash screen names it."
"Server and client must run the same build or the join fails."
"Match 1.20.1 files to 1.20.1 worlds and the problems go away."
Paraphrased from common support threads. Replace with real reviews once you collect them.
Citadel Mod is a library by AlexModGuy (Alexthe666). It carries shared code that mods such as Alex's Mobs, Alex's Caves and Ice and Fire need to run. It adds almost no content on its own.
The official file list covers 1.16.5, 1.17.1, 1.18.2, 1.19.4, 1.20.1 and 1.21.1. Check the mod page for the build that matches your game exactly.
No official Fabric build exists. Citadel targets Forge and NeoForge. Community ports for newer versions have appeared, so read each port's page and credits before using one.
Citadel is not offered for 1.12.2 in the current file list. Old 1.12.2 builds belong to a legacy era, so use a mod that lists 1.12.2 itself, or move to 1.20.1.
A mod you installed depends on Citadel. Add the Citadel file for the same Minecraft version and the same loader, then restart.
Not from the official list. The newest official files target 1.21.1, which is not the same as 1.21.11. Wait for an official release rather than forcing a mismatch.
Download it from the CurseForge link on this site or from Modrinth. Avoid re-uploaded jars on random sites.
Yes. If a server runs a mod that needs Citadel, the server and every player should have the same build.