
Caelus API
A coremod and API to provide developers access to elytra flight mechanics through an entity attribute.
About this Mod
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
Available Versions
How to Install Caelus API on Your Server
Order Server
Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).
Set fabric Loader
In the panel under "Egg", select the fabric loader and matching Minecraft version (1.21.5).
Install Mod
Open the mod browser in the dashboard and search for "Caelus API". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
1.21.5, 1.21.4, 1.21.1 (+20 more)
Server-side
✓ RequiredRecommended RAM
4 GB(min. 3 GB)Frequently Asked Questions
Caelus API server crashes on startup – what to do?
Most common cause: wrong fabric version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.21.5). You can switch loaders with one click in the panel.
Is Caelus API compatible with fabric and forge and neoforge?
Caelus API officially supports fabric, forge, neoforge for Minecraft 1.21.5, 1.21.4, 1.21.1. Note: Forge and Fabric mods are NOT cross-compatible – pick one loader and stick with it. The Mado dashboard automatically detects incompatible loader combinations.
Server lagging with Caelus API – how to optimize performance?
Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Caelus API consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.
Similar Mods
Rent Modded Server
Install Caelus API with just one click on your server.