Install

This page targets the current release, v26.2-r48.4. It is published and not STABLE. Install it on a test server first, with a backup of any world you care about.

Requirements

The launcher is a SourbyClip artifact. It fetches the externalized runtime libraries and the Mojang server jar, verifies them, and then starts the server. A first boot without network access will fail before the first tick.

Verify the jar

Download the jar and its checksum from the downloads page. Compare the checksum before executing anything. The release also ships an Ed25519 signature and a signed release manifest; the public key is inside the jar atMETA-INF/sourbycraft-release.pub.

sha256sum -c SourbyCraft-26.2-REL.jar.sha256
# macOS
shasum -a 256 -c SourbyCraft-26.2-REL.jar.sha256

First boot

Run the jar with Java 25 from a dedicated server directory. The process stays in the foreground; use a service manager or a terminal multiplexer for a long-lived server.

java -version   # Java 25
mkdir -p sourbycraft-server
cd sourbycraft-server
java -Xmx4G -jar ../SourbyCraft-26.2-REL.jar --nogui

The first boot creates the server directories and configuration. Read the console for the library fetch and verification messages. When the server reaches the first tick, connect with a 26.2 client and check the operator commands before adding plugins.

Directory layout

Build 48.4 keeps the pre-Build 49 configuration layout. Build 49 introduces renamed typed files and a TOML → YAML migration; that migration is not part of 48.4. Do not copy a Build 49 directory tree onto 48.4 and assume it is read.

Docker reference

The image is a JRE, not a published SourbyCraft image. Copy the release jar toserver.jar next to the compose file, mount it read-only, keep the world volume persistent, and pin the Java image digest for anything beyond a local test.

services:
  sourbycraft:
    image: eclipse-temurin:25-jre
    command:
      - java
      - -Xmx4G
      - -jar
      - /srv/server.jar
      - --nogui
    ports:
      - "25565:25565"
    volumes:
      - ./data:/srv
      - ./server.jar:/srv/server.jar:ro
    restart: unless-stopped

Common failures

• Unsupported class file version: the JVM is older than Java 25. Check java -version and the service unit’s environment.
• First boot cannot download: the launcher needs network access once. Check proxy and DNS settings; do not disable verification to get past it.
• Checksum mismatch: the download is incomplete or altered. Re-download; do not run it.
• Plugin timing errors: the plugin assumes a single main thread. Read Regions and the bridge notes before enabling compatibility mode.
• Server never reaches first tick: capture the full startup log and check the Java version, memory limit, and world permissions.