CaveBiomesAPI
by CelestialD
CaveBiomesAPI is a Forge library for 1.12.2 that lets mod developers stack 3D biomes vertically and extend world height limits.
What it does
The library gives developers an API for placing biomes at custom heights, including layers of underground ecosystems beneath the surface and biomes that reach above the usual sky limit. It is built for mod authors rather than players, and it expands vanilla world generation without changing it unless a feature is turned on.
Everything is opt-in, so a default setup keeps vanilla behavior byte-for-byte. Installation requires MixinBootstrap as a runtime dependency. Every player and the server need a copy of the mod. Files are published for Forge on 1.12.2 only, with 1.1.3 as the latest file from 2026-08-31. The code is under the GNU General Public License v3.0 or later and is open source.
Key features
Vertical 3D biomes
Biomes can be stacked beneath the surface, so one column of terrain can hold several distinct underground ecosystems.
Custom world height limits
Developers can configure and extend the world height, letting generated terrain reach above or below vanilla bounds.
World height configuration
A configuration layer controls the height settings, so the limits can be adjusted per world.
Clean developer API
The API is designed for integrating complex underground generation into other mods without reimplementing the core logic.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Required by 1 mod
Use cases
Underground ecosystems
Mod authors can create large cave systems where each layer carries a different biome.
Tall mountain biomes
Terrain can rise past the normal sky limit, which suits mountain or floating-island designs.
Who it’s for: Mod developers building world generation for Minecraft 1.12.2 Forge. Players rarely install it directly, since it adds no items or blocks on its own.
Questions
Does CaveBiomesAPI need MixinBootstrap?
Do servers need CaveBiomesAPI installed?
Which mod depends on CaveBiomesAPI?
In the catalog
CaveBiomesAPI is one of 3,514 Library mods on ModsFinder, and one of 1,576 Library mods for Forge. 2,920 mods support Minecraft 1.12.2.
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What the author says
!!! It is a library mod! By defaultmeans byte-for-byte vanilla behavior. Everything is opt-in.!!! CaveBiomesAPI is a core/library mod for Minecraft 1.12.2 designed specifically for mod developers. It significantly expands the vanilla world generation capabilities by introducing vertical (3D) biomes and custom world…
Official listing
- Modrinth page
- modrinth.com/mod/cavebiomesapi
- Owner
- CelestialD
- Published
- 2026-06-15
- Updated on Modrinth
- 2026-08-31
- Facts verified
- 2026-10-15