Left4Chat

Cross-server chat, private messages, AFK tracking and Discord account linking for the Left4Craft network. Runs on every backend Paper server and talks to the rest of the network over Redis, so a message typed on survival appears on hub and in Discord.

Features

• Network chat — publishes local chat to the minecraft.chat Redis channel and renders whatever comes back from other servers and the Discord bot. Colour (left4chat.color) and formatting (left4chat.format) codes are permission-gated.
• Private messages — /msg and /reply reach anyone on the network, addressed by username or nickname.
• /list — everyone online across all servers, staff first.
• /game — the server selector menu.
• /afk — away status, shared network-wide.
• /discord <code> — links a Minecraft account to a Discord account, stored in PostgreSQL.
• Spam defence — /verify opens an item-picking captcha; /chatlock restricts chat to verified players while riding out spambot waves.
• Console relay — runs commands published to minecraft.console.<server-name>.in, so the proxy and Discord bot can execute commands on this server. Every relayed command is logged. restart maps to stop, and players are moved to fallback-server first.
• Admin commands — /announce, /ggivecosmetic, /chatreload.

The console relay replaces the old standalone Left4Craft plugin — remove that plugin when installing Left4Chat, or every relayed command runs twice.

Requirements

Server	Paper 26.2
Java	25
Required	LuckPerms, Redis, PostgreSQL
Optional	Nicky (nicknames)
Replaces	Left4Craft (remove it)

Configuration

config.yml is generated on first start. It covers the Redis and PostgreSQL connections, the Redis channel/key names, announcement formats, the Discord invite, the /game menu contents and the permission node names.

The Redis keys under redis.keys are shared with the Velocity proxy plugin and the Discord bot. All three have to agree, so do not change one in isolation.

Database

Left4Chat owns one table, discord_users, and creates it if missing:

CREATE TABLE discord_users (
  uuid      UUID PRIMARY KEY,
  nick      VARCHAR(64),
  discordID BIGINT UNIQUE
)

Building

Needs JDK 25 — Paper 26.2's API class files are major version 69, so an older compiler cannot read them.

gradle build
# -> build/libs/left4chat-2.0.0.jar

libs/Nicky-2.0.0.jar is the sibling left4craft/Nicky build, used at compile time only. Refresh it after changing Nicky:

gradle -p ../Nicky build && cp ../Nicky/build/libs/Nicky-*.jar libs/