A mod for adding custom data to chunks without the hassle of writing custom packets, event handling,
\nloading hooks, and more.<\/p>\n
### Licensed under the LGPLv3 license<\/p>\n
### Originally developed by FalsePattern<\/p>\n
### Mod logo by Houstonruss<\/p>\n
Goals
\n—–<\/p>\n
It is a goal to provide a way to add custom data to chunks without having to modify any vanilla classes.
\nThe API will also provide a simple way to implement the custom serialization\/deserialization of the data,
\nboth for the networking and the NBT format.
\nAn optional goal is to provide a way to register DFUs for the custom data, but this is not a priority.<\/p>\n
Non-Goals
\n———<\/p>\n
It is not a goal to provide any kind of callback\/hook system for anything except saving\/loading and netcode, any kind
\nof extra behavior should be implemented in the mod using ChunkAPI.<\/p>\n
Storage is not provided by the API, the user is expected to implement their own storage system. A good example
\nis using a mixin to add a field to the chunk class, and using that field to store the data.<\/p>\n
Motivation
\n———-<\/p>\n
Modifying chunk packet data involved incompatibly modifying network packets, the chunk class, and the anvil chunk loader,
\nwhich is a lot of work for a simple feature. This mod provides a way to add custom data to chunks without having
\nto modify any of the vanilla classes yourself.<\/p>\n
API and spec
\n———–<\/p>\n
<\/p>\n
The API exposes a way to add custom data to chunks, and a way to register custom serializers for the data.<\/p>\n
### ChunkDataManager
\nThe `ChunkDataManager` itself is the primary class used for managing registrations, but does not implement functionality
\nby itself. For that, you need to use the `PacketDataManager`, `ChunkNBTDataManager`, and `SectionNBTDataManager`
\ninterfaces included inside the ChunkDataManager class.<\/p>\n
### ChunkDataManager.PacketData
\nThis interface is used for synchronizing data from the server to the client. If your data is only required on the server,
\nyou can freely skip implementing this interface.<\/p>\n
### ChunkDataManager.ChunkNBTData
\nThis interface is used for saving\/loading data from the chunk NBT. This is required if you want to keep persistent data
\nacross world reloads. Note, if you store data *per block* in the chunk, you should use `SectionNBTData` instead, as it
\nis designed with the internal chunk format in mind.<\/p>\n
### ChunkDataManager.SectionNBTData
\nThis interface is mostly identical to `ChunkNBTData`, but is designed for storing data per block in the chunk.
\nInstead of being called once per chunk, it is called once per chunk section (16x16x16 blocks, `ExtendedBlockStage` class).<\/p>\n
### ChunkDataRegistry
\nThis is where you actually register your manager. You need to do all registrations inside the `init` phase.
\nYou can also disable specific manager IDs by calling `disableDataManager`, but this is not recommended, and should
\nonly be used if you know what you are doing. You need to do all the disabling inside the `postInit` phase.<\/p>\n
### Packet specification<\/p>\n
ChunkAPI modifies the S21PacketChunkData and S26PacketMapChunkBulk vanilla packets, and overwrites their default
\nformats.<\/p>\n
All sizes in the tables below are specified in bytes.<\/p>\n
S21PacketChunkData new format:<\/p>\n
| Size (bytes) | Datatype | Name |
\n|————–|———-|—————————-|
\n| 4 | int | X position |
\n| 4 | int | Z position |
\n| 1 | bool | Force Update |
\n| 2 | short | ExtendedBlockStorage mask |
\n| 4 | int | Uncompressed data length |
\n| 4 | int | (n) Compressed data length |
\n| n | byte[n] | Compressed data |<\/p>\n
S26PacketMapChunkBulk new format:<\/p>\n
| Size (bytes) | Datatype | Name |
\n|————–|———————-|———————————|
\n| 2 | short | (n) Chunk count in packet |
\n| n * 4 | int[n] | Uncompressed chunk data lengths |
\n| 4 | int | (m) Compressed data length |
\n| 1 | 1 | Contains skylight data |
\n| m | byte[m] | Compressed data |
\n| n * 10 | (int, int, short)[n] | Chunk Headers (x, z, ebs mask) |<\/p>\n
In both cases, the compressed data is populated through the ChunkDataRegistryImpl.writeToBuffer method.
\nThe layout of this data is as follows:<\/p>\n
| Size (bytes) | Datatype | Name |
\n|————–|———-|——————-|
\n| 4 | int | (n) Manager count |
\n| n * varying | MGRData | Manager data |<\/p>\n
Manager data:<\/p>\n
| Size (bytes) | Datatype | Name |
\n|————–|———–|————————-|
\n| 4 | int | (n) Manager name length |
\n| n | UTF-8 str | Manager name |
\n| 4 | int | (m) Manager data length |
\n| m | byte[m] | Manager data |<\/p>\n
Dependencies
\n————<\/p>\n
FalsePatternLib<\/p>\n
UniMixins<\/p>\n","protected":false},"excerpt":{"rendered":"
Manage custom data inside chunks without hassle.<\/p>\n","protected":false},"featured_media":40108,"template":"","meta":{"_minecraft_slug":"chunkapi","_minecraft_project_id":"y0vBUOla","_minecraft_author":"FalsePattern","_minecraft_license":"LGPL-3.0-only","_minecraft_downloads":11749,"_minecraft_follows":8,"_minecraft_client_side":"required","_minecraft_server_side":"required","_minecraft_storage_type":"zip","_minecraft_archive_name":"chunkapi.zip","_minecraft_size_bytes":3375566,"_minecraft_version_count":21,"_minecraft_updated_at":"2026-05-16T03:02:55.244893Z","_minecraft_date_created":"2023-03-31T01:36:27.456246Z","_minecraft_date_modified":"2026-03-07T15:15:59.173319Z","_minecraft_project_url":"https:\/\/modrinth.com\/mod\/chunkapi","_minecraft_icon_attachment_id":40108,"_minecraft_imported_at":"2026-06-01T21:24:44+00:00","_minecraft_import_hash":"eadc7215e774cb2e4ca4ab63607252fc","_minecraft_versions":"","_minecraft_links":"","_minecraft_gallery":"","_minecraft_api_metadata":""},"mod_category":[104,873],"mod_loader":[106],"minecraft_version":[21],"class_list":["post-40107","mod","type-mod","status-publish","has-post-thumbnail","hentry","mod_category-forge","mod_category-library","mod_loader-forge","minecraft_version-1-7-10"],"yoast_head":"\n