High-performance Minecraft NBT Runtime (Memory / Ownership / Sync) for Fabric, Forge, and NeoForge.
InstantNBT optimizes NBT copy, save, and sync paths to reduce GC pressure and save-time hitching. It targets heavy-NBT workloads — not raw render FPS.
Maintained by MisoPy.
| Good fit | Poor fit |
|---|---|
| World save / chunk I/O | Empty-world render FPS |
| Large compound / inventory copies | Entity rendering or AI itself |
| GC hitch / save-spike reduction | “Install and FPS jumps forever” expectations |
Use Spark (/spark profiler start --timeout 30 --alloc) and inspect NBT / save-related frames when measuring.
- Minecraft 1.16.5 ~ 26.1.2 (Fabric / Forge / NeoForge — see matrix)
- Architectury API (all loaders)
- Fabric API on Fabric only
| Loader | Primary versions |
|---|---|
| Fabric | 1.16.5 … 26.1.2 |
| Forge | 1.17.1 … 1.20.1 |
| NeoForge | 1.20.4 … 26.1.2 |
- Tier A baseline: 1.20.1 Forge
- Forge 1.16.5 is not supported by the current LegacyForge toolchain
- Design notes: InstantNBT_ProjectPlan.md
- Drop the loader-matching jar into
mods - First launch creates
config/instantnbt-common.toml - Default mode is BALANCED (
nbtIoRedirect, CoW, pool, and related safe defaults)
Restart after major config changes. If an older heavy config remains, delete the toml and let it regenerate.
/instantnbt cow
/instantnbt benchmark
/instantnbt killswitch engage|reset
./gradlew :1.20.1-forge:compileJava
./gradlew :1.21.1-fabric:build
./gradlew runActiveClientActive StoneCutter version is stored in .sc_active_version (default: 1.20.1-forge).
MIT — see LICENSE.