SuperAccessTransformer
by commonplace
SuperAccessTransformer changes the access modifiers of classes, fields and methods at runtime, so code in other mods can reach members that are normally private, protected or final.
What it does
The mod works during game startup by intercepting class loading. It uses the java.lang.instrument API together with the ASM library to rewrite bytecode as classes are read, which is how it changes access rules without altering the mod files on disk. Most classes are made public and non-final, and private, protected and final modifiers are removed from fields and methods, with the exception of interfaces, enums and the VALUES fields.
The mod is aimed mainly at development environments, where mod authors need access to internal members while building and testing. It is published for Fabric and NeoForge across 16 release versions, 1.21 – 26.2. Either side can run it and neither needs it, and the code is under the MIT License and is open source.
On NeoForge, the mod loads as a coremod through the lowcodefml loader and appears in the NeoForge mod list. The project has a public source code repository, an issue tracker and a wiki, and an example setup for Architectury on NeoForge 1.21 is available in a test branch of the repository.
Key features
Runtime access widening
Most classes are made public and non-final, so other code can extend or reference them while the game runs.
Field and method modifiers
Private, protected and final modifiers are removed from fields and methods, and public access is added to them.
Excluded members
Interfaces, enums and the VALUES fields are skipped, so the rewrites leave those definitions unchanged.
Bytecode interception
Classes are modified as they load, through the java.lang.instrument API and the ASM library, without editing files on disk.
NeoForge mod list entry
On NeoForge the mod is registered as a coremod and shows up in the NeoForge mod list.
Compatibility
Latest build for each game version and loader.
26.x4 of 4 versions with builds
1.21.x12 of 12 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Who it’s for: Mod developers who need access to private or final members of game classes during development, and anyone who wants to read the source or report problems through the public repository.
Questions
Which loaders does SuperAccessTransformer support?
Does SuperAccessTransformer need to be installed on both sides?
Which game versions have files for SuperAccessTransformer?
Where can the source code be found?
In the catalog
SuperAccessTransformer is one of 8,016 Management mods on ModsFinder, and one of 5,930 Management mods for Fabric. 13,894 mods support Minecraft 26.2.
More from commonplace
Similar mods
What the author says
SuperAccessTransformer (SAT) is an open-source coremod for Minecraft 1.21+ that modifies access modifiers at runtime by injecting a Java Agent, converting most private, protected, and final members to public. It also includes a Gradle plugin, allowing the transformations to work in development environments without…
Official listing
- Modrinth page
- modrinth.com/mod/superaccesstransformer
- Owner
- commonplace
- Published
- 2026-06-07
- Updated on Modrinth
- 2026-07-28
- Facts verified
- 2026-10-15