SmartBroadcast

Minecraft 版本： 1.20 1.20.1 1.20.2 1.20.3 1.20.4 1.20.5 1.20.6

平台： folia paper purpur spigot

标签： management social utility

SmartBroadcast

中文

SmartBroadcast is an intelligent Minecraft LAN discovery protocol broadcaster plugin for Paper / Folia 1.20.1. It decides when to broadcast LAN server information, and what MOTD to broadcast, based on configurable expression rules.

Features

• Folia support: uses GlobalRegionScheduler and AsyncScheduler, with folia-supported: true in plugin.yml
• Minecraft LAN discovery protocol support: sends UDP multicast packets to 224.0.2.60:4445
• Multiple rules: rules are checked in order, and the first matching rule is used
• No-broadcast rules: a matched rule can set broadcast: false to suppress broadcasting
• Expression conditions: player count, whitelist status, port, MOTD, PlaceholderAPI placeholders, and more
• PlaceholderAPI support: PAPI placeholders can be used in both expressions and MOTD values
• MiniMessage support: custom MOTD values can use MiniMessage and will be converted to legacy text
• Current server MOTD support: use {server_motd} to broadcast the current Paper MOTD
• Hot reload support: /smartbroadcast reload

LAN Discovery Protocol

Minecraft clients listen for UDP multicast packets on 224.0.2.60:4445 while the multiplayer server list screen is open. The server should send a UTF-8 string in this format:

[MOTD]<server MOTD>[/MOTD][AD]<server port>[/AD]

Important: this protocol does not support Adventure rich text components. SmartBroadcast converts MiniMessage or the current server MOTD into legacy § text before broadcasting, so clients can parse it correctly.

Default Behavior

By default, the plugin broadcasts the current server MOTD only when at least one player is online:

rules:
  - name: "players-online"
    expression: "online > 0"
    broadcast: true
    motd: "{server_motd}"

If no rule matches, no LAN packet is sent.

Installation

1. Build the plugin:

./gradlew shadowJar

2. Copy the generated JAR into your server's plugins directory:

build/libs/SmartBroadcast-1.0.0.jar

3. Start your Paper / Folia 1.20.1 server.
4. Install PlaceholderAPI as well if you need PlaceholderAPI support.

Commands and Permissions

Configuration

broadcast:
  enabled: true
  address: "224.0.2.60"
  port: 4445
  interval-millis: 1500
  advertised-port: -1

• enabled: whether broadcasting is enabled
• address: LAN discovery multicast address, defaults to 224.0.2.60
• port: LAN discovery multicast port, defaults to 4445
• interval-millis: broadcast interval; vanilla uses about 1500ms
• advertised-port: server port advertised to clients; -1 means the current server port

Expression Rules

Rules are checked from top to bottom. The first rule whose expression evaluates to true is used.

Boolean Operators

&&  and
||  or
!   not

Example:

expression: "online > 0 && !whitelist"

Parentheses

expression: "(online > 0 && !whitelist) || %server_tps_1% >= 18"

Comparison Operators

==  equals
!=  not equals
>   greater than
>=  greater than or equal
<   less than
<=  less than or equal

String Operators

contains  contains substring
matches   regular expression match

Examples:

expression: "motd contains 'Survival'"
expression: "%server_name% matches 'Lobby.*'"

Literals

Supported literals:

• true
• false
• numbers such as 0 and 18.5
• strings such as 'Lobby' or "Survival"

Built-in Variables

PlaceholderAPI

When PlaceholderAPI is installed, PAPI placeholders can be used directly in expressions and MOTD values:

expression: "%server_online% > 0"
expression: "%server_tps_1% >= 18"
expression: "%server_name% contains 'Lobby'"

motd: "<green>%server_online%</green><gray>/</gray><yellow>%server_max_players%</yellow>"

MOTD Rendering

Broadcast Current Server MOTD

motd: "{server_motd}"

The plugin reads the current Paper MOTD and converts it to legacy text before broadcasting.

Custom MiniMessage MOTD

motd: "<gradient:#55ff55:#00aaaa>SmartBroadcast</gradient> <gray>|</gray> <yellow>%server_online%</yellow>"

Processing pipeline:

1. Apply PlaceholderAPI
2. Parse MiniMessage
3. Convert to legacy § text
4. Send a UDP multicast packet using the LAN discovery protocol

Multiple Rules Example

rules:
  - name: "hide-when-whitelist"
    expression: "whitelist == true"
    broadcast: false

  - name: "good-tps"
    expression: "online > 0 && %server_tps_1% >= 18"
    broadcast: true
    motd: "{server_motd}"

  - name: "fallback"
    expression: "online > 0"
    broadcast: true
    motd: "<yellow>Server is online</yellow>"

Build Requirements

• Java 17+
• Gradle
• Paper API 1.20.1

Build command:

./gradlew shadowJar

If Gradle Wrapper is not available locally, use an installed Gradle distribution:

gradle shadowJar

Testing Suggestions

• Start the plugin on Folia 1.20.1 and confirm there are no console errors
• Run /smartbroadcast reload to test hot reload
• Keep at least one player online and refresh the multiplayer server list from a client on the same LAN
• Test whether broadcast: false suppresses broadcasting
• Install PlaceholderAPI and test expressions such as %server_online% and %server_tps_1%

License

This project is licensed under the GNU General Public License v3.0. See LICENSE for details.