Worldgen Router

First release.

Installing it changes nothing. The starter config ships default = "allow", so your pack plays exactly as it did until you write a rule.

What it does

Group dimensions into world sets and decide what other mods may generate, spawn, or drop in each one — entirely from config, with no required content mods.

• Rules are per category (structure, feature, carver, entity, biome, item) and per enforcement point, so you can curate worldgen while leaving inventories alone.

• Precedence is fixed and total: deny_ids > allow_ids > deny_namespaces > allow_namespaces > default.

• /worldgenrouter explain tells you which rule decided and why, instead of leaving you to guess.

• /worldgenrouter reload re-reads rules live; a bad edit keeps the previous ones.

• Declare custom dimensions from config, with templates, fixed seeds and portal routing.

• Datapacks can ship a world set, or add denials to someone else's — but never loosen one.

Requirements

Minecraft 1.21.1 and NeoForge 21.1.x only. The version range is pinned deliberately: this mod hooks 1.21.1 worldgen internals directly. TerraBlender, if present, must be in [4.1.0.0, 4.2.0.0).

Known limitations

• TerraBlender + a curated set: biome-region isolation is not guaranteed and foreign biomes still appear. The mod warns about this at startup.

• Biolith has no verified adapter; a deny set with it installed refuses to boot rather than letting a global biome system through.

• Tags in rule lists are refused for now instead of silently matching nothing.

• Worldgen is not retroactive. Rules apply to chunks generated after them.

The optional worldgenrouter_cobblemon add-on is only needed if your pack has Cobblemon and you want its level rules.