
KesseractJS
A fork of the 1.16.5 version of KubeJS, maintained and extended
About this Mod
KesseractJS
Welcome to the 4th dimension.
KesseractJS is a fork of KubeJS, continuing its development for 1.16.5. It backport a lot of different features from the newer versions, and even adds some that are not present at all in the original mod. The latter are documented on a dedicated wiki, and support for those are offered on our discord server, so don't be afraid to ask there.
This mod depends on a modified fork of the Rhino JS parser called Rhizo, please install it before use. We also highly recommend you use ProbeJS Legacy during script development for better IDE support.
This project was made as a collaboration between Hellish Mods, ZZZank, and MundM2007, with the occasional help from Team Potato. Thank you guys <3
Feature showcase
- Fake mod registration
// In startup_scripts
Platform.registerFakeMod("notarealmodid").displayName("Hello World!")
onEvent('item.registry', event => {
event.create('notarealmodid:thing')
})

- Backports
// Welcome to the future babyyyy
// Falling block type
onEvent('block.registry', event => {
event.create('metal_pipe').material('falling')
})
// Custom music discs (https://github.com/KubeJS-Mods/KubeJS/issues/491)
onEvent('item.registry', event => {
event.create('disc_14').song('jamiroquai:vitrual_insanity')
})
// thickTexture/thinTexture and textureThick/textureThin intercompatibility
onEvent('fluid.registry', event => {
event.create('you_dont_want_to_know')
.thickTexture(0xFF0000)
.textureThick(0xFF0000) // Both methods work!
})
// JsonIO
let data = JsonIO.read('kubejs/data.json')
JsonIO.write('kubejs/data.json', {recursion: data})
// + more!
- Fixes. Lots of 'em.

- Full drag-and-drop compatability with old Kube scripts
- Continuous updates. More in the future!
Available Versions
How to Install KesseractJS 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 (1.16.5).
Install Mod
Open the mod browser in the dashboard and search for "KesseractJS". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
1.16.5, 1.16.4
Server-side
✓ RequiredRecommended RAM
4 GB(min. 3 GB)Frequently Asked Questions
KesseractJS 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 (1.16.5). You can switch loaders with one click in the panel.
Is KesseractJS compatible with fabric and forge and quilt?
KesseractJS officially supports fabric, forge, quilt for Minecraft 1.16.5, 1.16.4. 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 KesseractJS – how to optimize performance?
Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if KesseractJS 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.
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