JEI / REI / EMI WorldGen

What it does JEI WorldGen is an addon for Just Enough Items (JEI), Roughly Enough Items (REI), and EMI. It adds a new entry to those recipe viewers that tells you where and how ores generate in the world you're playing. Instead of relying on a static database, it reads the biome generation data straight from the save. That means the information matches the exact configuration of the world you are in, including any datapacks or modded biomes that alter ore placement. ## Who it's for If you want to know which Y-levels a specific ore spawns at, which biomes it appears in, or how rare it's, this mod gives you that answer inside the recipe viewer you already use. It works in singleplayer and on servers that have the mod installed. ## How it works The mod hooks into the world generation system and pulls data from the configured features that run during the UNDERGROUND_ORES and UNDERGROUND_DECORATION stages. It only reads features that use the minecraft:ore type. Any mod that adds ores through those standard stages and that feature type will show up automatically. No per-mod support is required. ## Compatibility requirements For a mod's ores to appear, two conditions must both be true. The mod must generate its ores in either the UNDERGROUND_ORES or UNDERGROUND_DECORATION generation stage. It must also use the minecraft:ore configured feature type. If either condition is missing, the ore won't be listed. ## Multiplayer behavior Ore generation data lives on the server side. The mod is marked as client-required and server-optional. For the information to appear while you play on a server, the server needs the mod installed. If the server does not have it, the client cannot fetch the data and the WorldGen entries stay empty. A workaround exists: join the same world in singleplayer first. The mod caches the biome data locally and will then display it when you reconnect to the server. You can also join a server that runs the mod even if you don't have it installed yourself. ## Loaders and versions The mod runs on NeoForge and Fabric. On Fabric you also need Fabric API. Supported Minecraft versions are 1.21, 1.21.1, and the 26.x series (26.1, 26.1.1, 26.1.2, 26.2, 26.3). ## Dependencies You must have one of the three supported recipe viewers installed: JEI, REI, or EMI. The Fabric build requires Fabric API. The NeoForge build has no extra library requirement beyond the loader itself.