How to Add a Custom Ore Spawn File to MMD OreSpawn Library

MMD OreSpawn Library reads every .json file it finds inside the orespawn folder and turns each entry into an actual ore generator. To add your own ore, you create a new JSON file there rather than editing an existing one.

Create the file

Open your game or server directory and locate the orespawn folder. Create a new text file and give it a .json extension, for example my_ores.json. The top level of the file must be a JSON array ([ ... ]), and each object in that array represents one dimension's worth of ore rules.

Fill in the fields

Each dimension object needs a dimension key (the numeric ID of the dimension you want to affect) and an ores array. Inside ores, list one object per ore with these keys: block (the registry name, like minecraft:iron_ore), size (how many blocks in a vein), variation (random spread on that size), frequency (how many times the game attempts to place it per chunk), and min_height/max_height for the vertical range. Save the file and reload the world or restart the game so the library parses it. If the JSON is malformed, the ore simply will not generate, so validate your brackets and commas carefully.