ModAPI.keygen contains the API for getting numerical item, block and entity IDs from a string. It looks at registries to derive the IDs, so IDs will not be automatically reserved until a block/item is actually registered into the game. Ideally, you’d want to call a keygen method just before registering your block.
Methods:
ModAPI.keygen.item(itemId: String) : number
var id = ModAPI.keygen.item("my_example_item");ModAPI.keygen.block(blockId: String) : number
var id = ModAPI.keygen.block("my_example_block");ModAPI.keygen.entity(entityId: String) : number
var id = ModAPI.keygen.entity("my_example_entity");