NilKit API

[4.1.0] - 2026-08-06

Byte Buddy patching framework

• Expanded the Byte Buddy integration from a thin helper wrapper into a reusable patching framework designed for Mixin-style runtime transformations.
• Added ByteBuddyPatch as a declarative patch definition API for targeting classes and applying multiple transformations without manually recreating AgentBuilder or transformer boilerplate.
• Added ByteBuddyPatchRegistry for managing multiple patches with deterministic ordering and configurable priorities.
• Added JVM descriptor-based method matching for more reliable targeting across mapped, obfuscated, and legacy Minecraft environments.
• Added patch validation through require(...), allowing transformations to fail immediately when an expected method or target is missing instead of silently continuing with an unapplied patch.
• Added reusable Advice-based injection support for method entry, method exit, constructors, argument modification, return-value modification, and exception handling.
• Added support for replacing complete method implementations through direct Byte Buddy interception.
• Added low-level transformation access through mutate(...), allowing patches to use raw Byte Buddy features such as MemberSubstitution, ASM visitors, field/method definitions, implemented interfaces, and custom builder mutations.
• Kept the underlying Byte Buddy API exposed so advanced transformations are not restricted by the higher-level NilKit abstraction.

Runtime transformation

• Added a NilLoader transformation bridge so registered Byte Buddy patches can participate directly in NilLoader class transformation without requiring Byte Buddy self-attachment.
• Added optional Instrumentation-based installation with retransformation support for environments where already-loaded classes must be patched.
• Preserved explicit Byte Buddy Agent attachment behavior; NilKit still does not automatically invoke ByteBuddyAgent.install() during SDK startup.
• Added composition support so multiple independent patches can safely target the same class through a single transformation pipeline.
• Improved transformation diagnostics and failure behavior for incompatible targets, incorrect mappings, and changed method descriptors.

Documentation

• Added documentation and examples for using the Byte Buddy patch API as a Mixin-style transformation layer.
• Documented patch registration, priorities, required targets, Advice injection, full method interception, and advanced raw Byte Buddy mutations.
• Added examples showing integration through the NilLoader transformer bridge without requiring a Java agent.