Modpack Checker

A lightweight Fabric mod for Minecraft servers to verify that clients are using the correct modpack version.

Features

• Disconnection Messages: Ability to set custom helpful disconnection messages
• Reload Command: reload the configuration by using /modpackchecker-reload
• LAN Multiplayer Support: Works with both dedicated servers and LAN multiplayer (can be disabled by setting enabled_lan to false)
• Development Mode: Use version "development" to always allow joining (useful for testing servers)

How It Works

1. Server sends a version check during login
2. Client replies with the version from modpack-checker.toml
3. Server compares it to its expected version
4. If mismatched, the player is kicked with a custom message

Configuration

Server (config/modpack-checker.toml):

# Modpack Checker Configuration
# This file contains both server and client configuration

# Modpack version of the server and client, that must match
# version "development" always allows joining
version = "1.0.0"

# Enable or disable modpack version checking
enable_server = true
enable_lan = true

# Kick messages for different scenarios
[messages]
# Message shown when client doesn't have the mod installed
no_mod = "Modpack not installed! \n\n Please install the modpack, version \"{version}\" \n <your-modpack-link>"

# Message shown when client has wrong version (use {version} as placeholder)
wrong_version = "Wrong modpack version installed! \n\n Please install the modpack version \"{version}\" \n <your-modpack-link>"

# Message shown when there's a server configuration error
server_error = "Server configuration error. Please contact an administrator."