Preloading Tricks Mod Wiki & Guide

Preloading Tricks Mod is designed for mod developers, not regular players. It lets you hook into the mod loader before mods officially initialize and transform Java classes at the bytecode level—much earlier than mixins can reach. If you're not writing a mod that needs to modify loader behavior or another mod's classes during startup, you don't need this mod.

Add a `ClassTransformConfig` attribute to your mod's manifest pointing to a JSON file (e.g., `classtransform.json`). In that JSON, specify the package and list the transformer classes you want to register. See the guide 'Set Up Class Transformers for Your Mod' for the exact format and working examples.

The mod provides hooks like `onSetupLanguageAdapter` and `onSetupMods` that fire before the mod loader officially initializes. These let you intercept and modify how adapters are set up or how the mod list is processed. Check 'Use Early Loader Hooks in Your Mod Code' for the full list and how to register them.

Yes—that's one of the main uses. By registering class transformers, you can edit the bytecode of any class (including from other mods) as soon as it loads into the JVM. See 'Modify Another Mod's Classes at Load Time' for setup instructions and examples.