CurseForge · Minecraft mod
Caelus API
A coremod and API to provide developers access to elytra flight mechanics through an entity attribute.
Quick answer
Which Caelus API release should I use?
Caelus API caelus-neoforge-8.0.1+1.21.4.jar targets 1.21.5, 1.21.4 with NeoForge. The project page does not say whether it belongs on the client. The project page does not say whether it belongs on the dedicated server. No extra mods listed for this file.
Where it goes
Is Caelus API required on the client, server, or both?
The project page does not say whether it belongs on the client. The project page does not say whether it belongs on the dedicated server.
The source does not explicitly classify this release as client-only or server-only.
What else does Caelus API caelus-neoforge-8.0.1+1.21.4.jar need?
caelus-neoforge-8.0.1+1.21.4.jar. Change the file and its required mods may change too.
This file does not list any required mods. Do not add a library just because a different file uses it.
This file does not list any required or optional mods.
Before you install it
Add Caelus API without breaking your instance.
Built for Caelus API caelus-neoforge-8.0.1+1.21.4.jar. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use caelus-neoforge-8.0.1+1.21.4.jar. It targets 1.21.5, 1.21.4 with NeoForge; another release may have different loader, side or dependency requirements.
- 02
Bring the mods it needs
This file does not list any required mods. Do not add a library just because a different file uses it.
- 03
Put it on the correct side
The project page does not say whether it belongs on the client. The project page does not say whether it belongs on the dedicated server.
- 04
Pick the file you checked
Use the “Get this file” button beside caelus-neoforge-8.0.1+1.21.4.jar. It opens that exact file at the source.
About this project
What does Caelus API add?
Caelus is a small utility mod that abstracts the hardcoded vanilla elytra behavior into a more generic elytra flight attribute and exposes this to mod developers seeking to implement elytra flight for their own mods.
All modders have to do is call CaelusApi.getInstance().getFallFlyingAttribute() wherever they want to apply a modifier to the flight attribute. The attribute has a default value of 0, which forbids any elytra flight. Attribute values greater than or equal to 1 will enable elytra flight. The vanilla elytra item has also been changed to use this attribute, keeping its behavior the same as normal.
For more information on how to interact with the attribute, see the Minecraft wiki.
Adding to Your Project:
Add the following to your build.gradle file:
repositories {
maven {
name = 'C4's Maven'
url = 'https://maven.theillusivec4.top/'
}
}
Forge
dependencies {
runtimeOnly "com.illusivesoulworks.caelus:caelus-forge:${version}"
compileOnly "com.illusivesoulworks.caelus:caelus-forge:${version}:api"
}
NeoForge
dependencies {
runtimeOnly "com.illusivesoulworks.caelus:caelus-neoforge:${version}"
compileOnly "com.illusivesoulworks.caelus:caelus-neoforge:${version}:api"
}
Replace ${version} with the version of Caelus that you want to use.
Support
Please report all bugs, issues, and feature requests to the issue tracker.
For non-technical support and questions, join the developer's Discord.
License
All source code and assets are licensed under LGPL-3.0-or-later.
Donations
Donations to the developer can be sent through Ko-fi.
Affiliates

Project description from CurseForge.
Pick your setup
Caelus API by Minecraft version and loader
Choose the version and loader you play, then open the matching release.
1.21.4
1 loader build1.21.1
2 loader builds1.21
2 loader builds1.20.6
2 loader builds1.20.4
2 loader builds1.20.2
1 loader build1.20.1
2 loader builds1.20
2 loader builds1.19.4
1 loader build1.19.3
1 loader build1.19.2
1 loader buildShowing the newest 12 of 26 game versions. Older files are in the list below.
Check the dependencies, then try the file in a copied instance before changing a world you care about.
Recent files
Caelus API versions and loaders
caelus-neoforge-8.0.1+1.21.4.jar
23 Jul 2025
caelus-neoforge-8.0.0+1.21.4.jar
21 Jun 2025
caelus-neoforge-7.0.1+1.21.1.jar
5 Sept 2024
caelus-forge-7.0.1+1.21.1.jar
5 Sept 2024
caelus-neoforge-7.0.0+1.21.jar
19 Jun 2024
caelus-forge-7.0.0+1.21.jar
19 Jun 2024
caelus-neoforge-6.0.0+1.20.6.jar
7 May 2024
caelus-forge-6.0.0+1.20.6.jar
7 May 2024
caelus-neoforge-5.1.0+1.20.4.jar
22 Apr 2024
caelus-forge-5.1.0+1.20.4.jar
22 Apr 2024
caelus-forge-3.2.0+1.20.1.jar
22 Apr 2024
3.2.0+1.20.1
caelus-forge-3.2.0+1.20.1.jar
22 Apr 2024
Looking for an older file? The official CurseForge project page is in Resources.