README

Minecraft NBT

A pure-PHP library for reading, writing, and manipulating Minecraft's NBT (Named Binary Tag) format, in both binary (file and network) form and SNBT.

Features

• Binary NBT: read and write the file format (named root) and the network format (unnamed root, Minecraft 1.20.2+)
• Compression: auto-detects GZip and Zlib on read; choose any of GZip, Zlib, or none on write
• SNBT: parse and render stringified NBT, with optional pretty-printing and configurable quote style
• 1.21.5 SNBT extensions: typed-array prefixes ([B;...], [I;...], [L;...]), signed/unsigned suffixes (42ub, 100sl, ...), hex (0xFF) and binary (0b1010) literals, underscore digit separators, trailing commas
• All 13 tag types: Byte, Short, Int, Long, Float, Double, ByteArray, String, List, Compound, IntArray, LongArray, plus End for empty lists
• Type-safe construction: element-type validation on List and array tags, range-checked numeric tags
• PHPStan level max: full generic annotations on Tag<TValue>, CompoundTag, ListTag, and the Nbt facade

Requirements

• PHP 8.5 or newer
• ext-zlib (compiled in by default on most distributions)

Installation

Install via Composer:

composer require cartograph/minecraft-nbt

Quick start

Build a tag tree and write it to a file:

use Cartograph\NBT\Nbt;

$tag = Nbt::compound([
    'name'  => Nbt::string('Bananrama'),
    'level' => Nbt::int(42),
]);

Nbt::writeFile($tag, 'player.nbt');

That's a complete, runnable example, with no fixtures and no setup. The output is a GZip-compressed binary NBT file with a TAG_Compound root containing one string and one int child.

To read it back:

$tag = Nbt::readFile('player.nbt');

echo $tag->get('name')->value();      // "Bananrama"
echo $tag->get('level')->value();     // 42

Concepts

NBT is a tree of typed tags. Every tree has a CompoundTag at its root, which is an ordered map of named children. Children can be other compounds (nesting), ListTags (homogeneous, ordered sequences of tags), or any of the leaf types: Byte, Short, Int, Long, Float, Double, String, ByteArray, IntArray, or LongArray.

The same tree can be serialised two ways:

• Binary NBT, the compact wire format used by Minecraft itself, with optional GZip or Zlib compression
• SNBT, a human-readable text representation, similar to JSON with type suffixes (42b, 1.5f, [L;1L,2L,3L])

This library reads, writes, parses, and renders both.

Usage

Read a binary file

readFile auto-detects GZip and Zlib compression from the file's leading bytes; uncompressed files work too.

use Cartograph\NBT\Nbt;

$level = Nbt::readFile('level.dat');

echo $level->get('Data')->get('LevelName')->value();

Write a binary file

GZip is the default. Pass a different Compression to override.

use Cartograph\NBT\Binary\Compression;
use Cartograph\NBT\Nbt;

Nbt::writeFile($tag, 'data.nbt');                                    // GZip
Nbt::writeFile($tag, 'data.zlib.nbt', '', Compression::Zlib);
Nbt::writeFile($tag, 'data.raw.nbt', '', Compression::None);

The third argument is the root tag's name (most files use an empty string).

Parse SNBT

parseSnbt accepts the full SNBT grammar including 1.21.5 extensions: typed-array prefixes, signed/unsigned suffixes, hex/binary literals, underscore digit separators, and trailing commas.

use Cartograph\NBT\Nbt;

$tag = Nbt::parseSnbt('{name: "Bananrama", level: 42b, scores: [1, 2, 3]}');

echo $tag->get('name')->value();           // "Bananrama"
echo $tag->get('level')->value();          //  42 (ByteTag)
echo $tag->get('scores')->get(1)->value(); //  2  (IntTag)

Render SNBT

Two modes via SnbtOptions: compact (default) and pretty.

use Cartograph\NBT\Nbt;
use Cartograph\NBT\Snbt\SnbtOptions;

echo Nbt::renderSnbt($tag);
// {name:Bananrama,level:42b,scores:[1,2,3,],}

echo Nbt::renderSnbt($tag, new SnbtOptions(prettyPrint: true));
// {
//     name:Bananrama,
//     level:42b,
//     scores:[
//         1,
//         2,
//         3,
//     ],
// }

SnbtOptions also lets you force-quote keys (quoteKeys: true), pick a preferred quote style (quoteStyle: QuoteStyle::Single), and choose the indentation unit.

Network format (Minecraft 1.20.2+)

The network protocol uses an unnamed root compound. Nbt::readNetworkBinary and Nbt::writeNetworkBinary handle it.

use Cartograph\NBT\Nbt;

$bytes = Nbt::writeNetworkBinary($tag);
$tag   = Nbt::readNetworkBinary($bytes);

Class overview

All tag classes live in the Cartograph\NBT\Tags namespace.

The Nbt facade has a factory method for each (Nbt::byte(), Nbt::compound(), ...) that returns the corresponding tag instance.

Compatibility

This library targets the Java Edition NBT format. All 13 tag types (including TAG_End for empty lists) are supported.

• File format: fully supported, all Minecraft Java versions
• Network format: Minecraft Java 1.20.2 and newer (unnamed root compound)
• Compression: GZip, Zlib, and uncompressed
• SNBT: classic syntax plus the 1.21.5 grammar extensions

Bedrock Edition's NBT variant (little-endian, varint-prefixed) is not supported.

Contributing

Bug reports, feature requests, and pull requests are welcome at github.com/cartographgg/minecraft-nbt. See CONTRIBUTING.md for development setup and the required checks (tests, static analysis, code style, and mutation testing). Each check has a Composer script: composer test, composer static, composer style, and composer mutation.

License

Released under the MIT License. © Cartograph contributors.

Maintained as part of Cartograph, a Minecraft server directory and monitoring platform. The library is self-contained and has no Cartograph-specific behaviour; use it anywhere you need to work with NBT data in PHP.