Fermion - Java coremodding library for Forge 1.14+

With the release of Minecraft 1.13, Forge developers completely rewrote the mod system architecture. During these changes, the possibility of creating Java coremods was almost eliminated, replaced by a JavaScript implementation.

The Fermion library brings back the familiar approach to creating coremods in Java, but at a safer level. It prevents class loading issues and uses the Visitor pattern instead of the outdated ClassNode.

For Regular Players

If you install this mod separately, nothing will change in the game - just three additional entries will appear in the mod list. Fermion is a library intended exclusively for developers. Activation will only occur after installing a Launch Plugin or a mod that contains one.

For Developers

This library provides a service platform for creating Launch Plugin without needing to dive into the internal mechanisms of ModLauncher or Forge. Detailed documentation with a guide for creating Launch Plugin for your mods is available on GitHub.

Key Advantages

Stable API and ready-made components, compatible between Minecraft versions: you won't have to rewrite the coremod structure when ModLauncher changes, unless the bytecode of the edited methods changes.

Flexible configuration system: users can enable or disable any transformers, as well as configure them according to their needs.

Full IDE support: unlike JavaScript implementation, Launch Plugins are written in Java, providing syntax highlighting and code autocompletion in the development environment.

Target descriptors: no longer need to load classes to reference them or rely only on method names. Use Class-, Method-, and FieldDescriptors for more efficient work.

Launch Plugin and mod in one file without the need to extract components from the archive.

Quick error detection: when there are problems in creating the Launch Plugin, the game won't even start, and an error message will appear in the logs, allowing automatic problem identification.

Important Information

For Fermion to load correctly by the Forge system, the library creates its copy during runtime, forming a new JAR file in the mods directory. This is a workaround for the limitations of the ModLauncher loading system. This is not a separate mod or malicious attack - you can freely decompile the JAR or compare it with the original. The created file is automatically deleted when Minecraft closes.