Haven Skyblock Builder is a flexible and modpack-friendly world builder for Skyblock, CaveBlock, OceanBlock, VolcanoBlock, and other custom world types.

It adds a custom world preset, configurable island templates, team islands, island visits, spawn islands, terrain layers, world-generation controls, and an in-game island management screen.

Island distance, height, spawn positions, cooldowns, Nether generation, terrain layers, biome restrictions, structures, carvers, placed features, additional islands, and template spawn offsets are all configurable.

Important Information

Haven Skyblock Builder is still under active development. Report problems through GitHub Issues.
This mod does not provide island protection, so make sure you use a mod like FTB Chunks or other types.
For singleplayer, create a world using the Haven Skyblock world preset.
For dedicated servers, set the following before generating the world: level-type=haven_skyblock_builder:skyblock_world

Custom World Generation

The Overworld uses configurable Skyblock generation.
The Nether can use Skyblock generation or normal Minecraft generation.
The End uses normal Minecraft generation.
Custom terrain layers can be used to create Skyblock, CaveBlock, OceanBlock, VolcanoBlock, and similar worlds.
Vanilla and modded structures, carvers, and placed features can be enabled through the config.

Custom Island Templates

Players can create islands from configurable .nbt structure templates.
Templates are loaded from config/HavenSkyblockBuilder/Templates.
Each template can have its own player spawn offset and look direction.
A rotatable and zoomable template preview is shown before island creation.

Additional Islands

Additional structures can automatically spawn around a main island template.
Additional island templates are loaded from config/HavenSkyblockBuilder/AdditionalIslands.
Each additional structure has configurable X, Y, and Z offsets.

Spawn Island

A configurable spawn island is created when the world is first generated.
Replace it using config/HavenSkyblockBuilder/spawn_island.nbt.
The spawn island is only placed once per world.
New players without an island are automatically sent to spawn.

Teams and Island Management

Each island has its own team.
Invite players, accept or deny invitations, leave teams, and request to join other islands.
Team leaders can manage members, permissions, invitations, join requests, island visits, island spawn positions, team names, leadership, and disbanding.
Island ownership can be transferred to another team member.
Team data is stored separately for each world.

Island Screen

Press J in-game to open the Haven Skyblock Builder GUI.
Browse every active island team and view its member count.
View team information, visit islands, or request to join them.
Filter teams by visit status, join requests, empty teams, and disbanded teams.
Manage island settings, invitations, requests, permissions, and members.
Return directly to your home island or world spawn.

Island Visits

Team leaders can allow or block visits to their island.
Players can visit public team islands from commands or the island GUI.
Visitors can be deported back to spawn by the island team.

Configurable Cooldowns

Separate cooldowns are available for island creation, island home, spawn teleporting, and island visits.

Biome Restrictions

Blacklist specific vanilla or modded biomes from island placement.
Biome IDs can be generated directly from the loaded server.

Layer Config

Terrain layers are built from the bottom of the dimension upward using a simple block and count format.

minecraft:bedrock,3*minecraft:stone,minecraft:grass_block

The Overworld supports up to 384 configured layers.
The Nether supports up to 256 configured layers.
Leaving the Overworld layer config empty creates a normal empty Skyblock world.

Commands

Commands are available for island creation, home teleporting, spawn teleporting, team invitations, join requests, island visits, leadership management, member management, and administration.

Example:

/havensb island create classic_island My Island

Generated ID Lists

Administrators can generate lists containing valid IDs from all loaded vanilla and modded content:

Structures
Biomes
Placed features
Carvers

Generated files are saved in config/HavenSkyblockBuilder/generatedjsons.

Documentation

See the README on GitHub for the full command list, config options, layer examples, and template documentation.