ARRP Library Wiki

ARRP Library Wiki & Guide

wiki.9minecraft.net/arrp-library/

ARRP Library is an API for fabric that allows for the generation of resource packs at runtime via code. This allows you to add recipes / loottables / models / blockstates without json and in code, as well as allowing conditional resources. All while being compatible with normal resource packs.

Guides

Step-by-step, in-game.

Adding Conditional Resources That Only Load When a Mod Is PresentWhy Conditions Matter ARRP's headline feature is conditional resources: you can emit a recipe, model, or loot table…Adding Loot Tables Through ARRP CodeBuilding a Loot Table Programmatically ARRP can generate loot table JSON at runtime, which is useful when drops…Generating Blockstates and Models Without JSON FilesEmitting Models from Code ARRP can produce blockstate and model JSON at runtime, so you never hand-write model files.…How to Generate a Custom Recipe at Runtime with ARRPRegistering a Recipe in Code ARRP lets you build recipes without writing JSON files. You create a resource generator…

Frequently asked questions

How do I get started with ARRP in my mod?

Add ARRP as a dependency in your build configuration, then call the ARRP resource generation entry point during mod initialization so your generated resources are registered before the resource reload happens. From there you can start adding recipes, models, blockstates, and loot tables in code.

Do I need to write any JSON files at all when using ARRP?

No. ARRP lets you build recipes, loot tables, models, and blockstates entirely in Java code, and the generated output is injected as a virtual resource pack at runtime. You can still ship normal JSON resource packs alongside it, since ARRP is designed to be compatible with them.

When does ARRP actually generate the resources?

Generation happens at runtime, typically during resource reload, so the pack is rebuilt each time resources are reloaded rather than being written to disk permanently. This means changes to your generation code take effect on the next reload without you shipping new files.

Why aren't my ARRP recipes showing up in game?

The most common causes are registering the generation too late (after the resource reload has already run) or using the wrong resource path/namespace for the recipe. Make sure your generation callback runs during the appropriate initialization phase and that the identifier matches where the game expects to find it.

See all 10 ARRP Library questions ›

Other wikis you may find useful.