Decompiling the Server

The Hytale server JAR is not obfuscated, making it easy to explore the source code. This guide shows how to download and decompile it.

Quick Start

Release
Pre-release

# create working directory
mkdir -p .sources && cd .sources

# get latest version and download
VERSION=$(curl -s "https://maven.hytale.com/release/com/hypixel/hytale/Server/maven-metadata.xml" | sed -n 's/.*<latest>\([^<]*\)<.*/\1/p')
curl -O "https://maven.hytale.com/release/com/hypixel/hytale/Server/${VERSION}/Server-${VERSION}.jar"
mv "Server-${VERSION}.jar" HytaleServer.jar

# decompile with Vineflower (via Docker)
docker run --rm -v "$(pwd):/sources" eclipse-temurin:21-jdk-alpine sh -c '
  apk add --no-cache curl > /dev/null 2>&1
  curl -fsSL -o /tmp/vf.jar https://github.com/Vineflower/vineflower/releases/download/1.11.2/vineflower-1.11.2.jar
  java -jar /tmp/vf.jar \
    --decompile-generics=1 \
    --decompile-switch-expressions=1 \
    --pattern-matching=1 \
    --use-debug-var-names=1 \
    --use-method-parameters=1 \
    --remove-bridge=1 \
    --threads=0 \
    /sources/HytaleServer.jar /sources/server
'

# create working directory
mkdir -p .sources && cd .sources

# get latest pre-release version and download
VERSION=$(curl -s "https://maven.hytale.com/pre-release/com/hypixel/hytale/Server/maven-metadata.xml" | sed -n 's/.*<latest>\([^<]*\)<.*/\1/p')
curl -O "https://maven.hytale.com/pre-release/com/hypixel/hytale/Server/${VERSION}/Server-${VERSION}.jar"
mv "Server-${VERSION}.jar" HytaleServer.jar

# decompile with Vineflower (via Docker)
docker run --rm -v "$(pwd):/sources" eclipse-temurin:21-jdk-alpine sh -c '
  apk add --no-cache curl > /dev/null 2>&1
  curl -fsSL -o /tmp/vf.jar https://github.com/Vineflower/vineflower/releases/download/1.11.2/vineflower-1.11.2.jar
  java -jar /tmp/vf.jar \
    --decompile-generics=1 \
    --decompile-switch-expressions=1 \
    --pattern-matching=1 \
    --use-debug-var-names=1 \
    --use-method-parameters=1 \
    --remove-bridge=1 \
    --threads=0 \
    /sources/HytaleServer.jar /sources/server
'

Output will be in .sources/server/.

Finding the Latest Version

Release
Pre-release

Get the latest version from maven-metadata.xml:

curl -s "https://maven.hytale.com/release/com/hypixel/hytale/Server/maven-metadata.xml" | sed -n 's/.*<latest>\([^<]*\)<.*/\1/p'

List all available versions:

curl -s "https://maven.hytale.com/release/com/hypixel/hytale/Server/maven-metadata.xml" | grep '<version>'

Get the latest pre-release version from maven-metadata.xml:

curl -s "https://maven.hytale.com/pre-release/com/hypixel/hytale/Server/maven-metadata.xml" | sed -n 's/.*<latest>\([^<]*\)<.*/\1/p'

List all available pre-release versions:

curl -s "https://maven.hytale.com/pre-release/com/hypixel/hytale/Server/maven-metadata.xml" | grep '<version>'

Key Packages

After decompiling, explore these packages:

Package	Contents
`com.hypixel.hytale.server.core.plugin`	Mod API: `JavaPlugin`, `PluginBase`
`com.hypixel.hytale.server.core.command`	Command system
`com.hypixel.hytale.event`	Event system
`com.hypixel.hytale.assetstore`	Asset loading
`com.hypixel.hytale.builtin`	Built-in plugins (good examples)
`com.hypixel.hytale.codec`	Serialization system