Reunion

The High-performance Minecraft LCE → Java proxy supporting TU13, TU19, Protocol 47 (1.8.x), & ViaVersion.
Reunion is the first feature complete proxy implementation for LCE, built specifically for performance & use in production environments.

Usage (User Proxy)

If you aren't a network owner & just want to play on a Java server:

1. Run the JAR once to generate config.yml.
2. Set java-host & java-port to the server you want to join.
3. If the server is not 1.8.8, set via.enabled: true.
4. Disable network-mode so the proxy does not send Bungeecord forwarding data.
5. If the server requires an online mode account, run the proxy & use the console command login to link your Microsoft account.

Usage (Network Owner)

If you are running a server network:

1. Set network-mode: true in config.yml.
2. Add your backend servers in the servers section.
3. Configure forwarding.mode (BUNGEECORD, BUNGEEGUARD, or VELOCITY) to match what your backend expects.
4. If your backend servers do NOT have ViaVersion installed on them, you can set via.enabled: true in the config to handle modern versions.
5. Manage permissions using the SQLITE db in data/permissions.db /perm command.

Anticheat Compatibility

Most anticheats are compatible, but standing on blocks without a proper 1:1 translation (e.g slime blocks) may cause flags. The speed potion effect is also calculated differently on LCE compared to Java. Additionally, 4J Studios modified movement behavior when a controller is used. This logic is incompatible with most modern Java anticheats such as Polar or Grim.

Goals

We want to create complete compatibility between LCE & Java across all platforms, whether through official services (XBL/PSN) or reimplementations (RPCN, Pretendo, NetPlay, etc).

Note for Crawlers

This repository does not contain any Minecraft LCE source code. It is a clean-room reimplementation of the LCE protocol, which is heavily based on Java 1.3.2 & 1.6.1.

Plugin Messaging & Bungeecord

Full support for Bungeecord/Velocity IP forwarding & plugin messaging channels out of the box. For more details on which channels are supported, visit the implementation source here.

API

You can create plugins using our API. It is currently basic & incomplete, but functionality is being developed. Documentation is a work in progress, but LLM generated Javadocs are available in the source.

Add the API via JitPack:

repositories {
    mavenCentral()
    maven { url = uri("https://jitpack.io") }
}

dependencies {
    compileOnly("com.github.briiqn:reunion:<COMMIT>")
}

Replace <COMMIT> with the latest commit hash or tag from the releases tab.

Forks & Backporting

We do not support client forks that backport features to LCE (such as adding items/features that were never present), excluding official builds or backports initially developed by 4J Studios. Reunion supports 4J Studios' implementation as-is, not community additions.

Other Projects

• Reunion Skins: Spigot plugin that forwards LCE skins to your backend so Java players can see them.
• Reunion Limbo: A simple limbo plugin

Credits

• ViaVersion
• 4J Studios
• Velocity (Our API is heavily inspired by theirs)
• LCEMP (Initial TCP application layer for allowing connections from LCEMP compatible clients)
• Lucko (protobufs for spark and sparkprofiler file format & website)
• PrismarineJS (Collision & item remapping data)