Schema JS
If you have ever tried to script interactions between several tech or magic mods at once, you already know the pain. KubeJS gives you a powerful scripting layer, but it does not natively understand every mod's internal systems. That is exactly the gap Schema JS was built to fill. It is an addon for KubeJS that aims to provide as much support for other mods as possible, turning scattered mod APIs into something you can actually script against.
The philosophy behind the project is simple: if a mod exists and players want to automate it, Schema JS should try to support it. The developer openly invites mod requests on the issue tracker, so the list of supported integrations keeps growing with community feedback rather than being locked to a fixed roadmap.
What Schema JS Actually Does
Schema JS acts as a bridge. Instead of writing fragile custom Java or relying on undocumented behavior, you get dedicated bindings that expose a mod's machines, recipes, and data to the KubeJS event system. That means you can write scripts that react to in-game events, modify recipes on the fly, or tie two unrelated mods together in ways their authors never planned.
Because it is a KubeJS addon, it inherits the same reload-friendly workflow. You tweak a script, reload, and see the result without restarting the game, which makes iterating on complex cross-mod logic far less painful.
Supported Minecraft Versions and Loaders
Schema JS is built for Minecraft 1.18.2, 1.19.2, and 1.20.1 on the Forge loader, matching the versions where KubeJS itself is most actively maintained. If you run a modpack on one of these versions, you are in the right place. Always check that your KubeJS build matches the Schema JS release you plan to use, since mismatched versions are the most common cause of startup crashes.
Mods You Can Script With
The supported list covers a healthy slice of the modded ecosystem. Notable integrations include:
- Mystical Agriculture for custom crops, essences, and infusion recipes
- Applied Energistics 2 for automation and network-related scripting
- Horse Powered for its animal-driven machinery
- BBL Casting, BBL Strainers, and BBL Utility for the BBL family of mods
- Powah for energy generation and storage tweaks
- Ender IO for conduits, machines, and alloy recipes
- Extended Crafting for table and crafting core recipes
The full, always-current list lives on the project wiki. That wiki is the best place to confirm what is supported right now, and it also shows which mods are queued to be added. If something you need is missing, you can request it yourself and even contribute to the list.
How to Install Schema JS
Getting started is straightforward, and knowing how to install it correctly saves a lot of troubleshooting later.
- Install a compatible version of Minecraft Forge for your chosen version.
- Add KubeJS to your mods folder first, since Schema JS depends on it.
- Place the Schema JS jar into the same mods folder.
- Launch the game once to generate the config and script directories.
- Write your scripts in the KubeJS server scripts folder and reload to test.
If you would rather skip manual file juggling, the foxygame.net launcher handles the whole chain for you. Its built-in add-on catalog lets you search for Schema JS, confirm the correct Minecraft version, and install it alongside KubeJS in a single click, with automatic updates keeping both in sync afterward. That removes the guesswork around matching builds, which is where most manual setups go wrong.
Why It Matters for Modpack Authors
For pack developers, Schema JS is less of a convenience and more of a design tool. You can gate progression behind custom recipes, rebalance a mod's output without editing its config files, or create quest-style interactions that span several mods at once. Because everything runs through KubeJS, your changes stay in script files that are easy to version control and share.
Players benefit too. A pack using Schema JS can offer smoother cross-mod integration, fewer broken recipes, and custom content that feels native rather than bolted on.
Getting Support and Contributing
The project has an active support channel through the BBL Discord, where you can report bugs, suggest features, and ask for help with tricky scripts. There is also a Patreon that grants alpha access to modpacks and mods still in development, which is a nice way to support continued work if you find the addon useful.
Final Thoughts
Schema JS fills a real niche. If you have ever wanted KubeJS to speak the language of your favorite tech or farming mod, this addon is the answer. Grab the version that matches your Minecraft release, keep KubeJS updated alongside it, and check the wiki whenever you are unsure what is supported. Once you start scripting across mods, it is hard to go back to doing it the hard way.