EmptyNet

A self-standing Paper 1.21.1+ plugin that provides server transfers, a built-in login/register system with 2FA

Features

• Self-standing - No BungeeCord, Velocity, or any other proxy required
• Unlimited servers - Add as many server entries as you want in the config
• Custom commands - Each server gets its own command (e.g., /lobby, /survival)
• Server listing - /server lists all available servers
• Server back - /serverback returns to the last server you connected to
• Transfer timeout - Configurable timeout that notifies players if a transfer fails to connect
• Login/Register system - Players must register and login before playing
• 2FA support - Optional 6-digit 2FA code for extra security
• H2 database - All passwords stored as BCrypt hashes in an embedded H2 database
• Config toggles - Enable/disable the transfer system and login system independently
• Custom messages - Configure the message shown when connecting to each server
• Tab completion - Auto-completes server names in /server command

Requirements

• Paper 1.21.1 or higher
• Java 21 or higher

Installation

1. Download the EmptyNet-1.2.0.jar from the releases page
2. Place the jar file in your server's plugins/ folder
3. Restart your server
4. Edit the plugins/EmptyNet/config.yml to configure your servers
5. Restart your server or use /reload to apply changes

Configuration

Edit plugins/EmptyNet/config.yml:

# EmptyNet Configuration
# Add as many servers as you want by copying and pasting the section below.

# =====================================================
# Transfer Settings
# =====================================================

# Master switch for the server transfer system. Set to false to disable all transfer commands.
transfer-enabled: true

# Time in seconds to wait for a player to successfully connect to the target server.
# If the player does not connect within this time, they will be notified that the
# connection failed and can try again. Set to 0 to disable.
timeout: 120

# =====================================================
# Login System
# =====================================================

# Master switch for the login/register system. Set to false to disable.
login-enabled: true

# Give players the blindness effect while they are not logged in.
login-blindness: true

# Kick players who do not login/register within the timeout. Set to false to disable.
login-kick-enabled: true

# Time in seconds a player has to login/register before being kicked.
login-kick-timeout: 30

servers:
  example:
    # The display name shown to players
    name: "Example Server"
    # The command name (e.g., /example)
    command: "example"
    # The server IP and port to connect to
    ip: "127.0.0.1:25566"
    # The message shown to the player when connecting
    message: "&aConnecting to Example Server..."

Adding More Servers

Simply copy and paste the server entry block and change the values:

servers:
  lobby:
    name: "Lobby"
    command: "lobby"
    ip: "192.168.1.10:25565"
    message: "&aSending you to the Lobby..."

  survival:
    name: "Survival Server"
    command: "survival"
    ip: "192.168.1.10:25566"
    message: "&aConnecting to Survival..."

  creative:
    name: "Creative Server"
    command: "creative"
    ip: "192.168.1.10:25567"
    message: "&aTeleporting to Creative..."

Config Fields

Field	Description	Example
transfer-enabled	Master switch for the transfer system	true
timeout	Seconds to wait before considering a transfer failed (0 = disabled)	120
login-enabled	Master switch for the login/register system	true
login-blindness	Give blindness to unauthenticated players	true
login-kick-enabled	Kick players who don't login in time	true
login-kick-timeout	Seconds before unauthenticated players are kicked	30
name	Display name shown in /server list	"Survival Server"
command	The command players use (e.g., /survival)	"survival"
ip	Server IP address and port	"192.168.1.10:25566"
message	Message shown when connecting (use & for color codes)	"&aConnecting..."

Commands

Command	Description	Permission
/server	Lists all available servers	emptynet.use
/server <name>	Connect to a specific server	emptynet.use
/serverback	Return to your last server	emptynet.use
/<command>	Direct command for each configured server	emptynet.use
/register <password> <confirm>	Register an account	true
/login <password>	Login to your account	true
/2fa <code>	Enter your 2FA code after login	true
/2fa set <code>	Set a 6-digit 2FA code (while logged in)	true
/2fa remove	Remove your 2FA code (while logged in)	true

Examples

• /server - Shows a list of all configured servers
• /server lobby - Connects to the "lobby" server
• /lobby - Same as above (if configured with command: "lobby")
• /serverback - Returns to the server you were on before
• /register mypass mypass - Registers a new account
• /login mypass - Logs in with your password
• /2fa 123456 - Enters your 2FA code after login
• /2fa set 654321 - Sets a 2FA code (while logged in)
• /2fa remove - Removes your 2FA code (while logged in)

Permissions

Permission	Description	Default
emptynet.use	Allows using /server and /serverback commands	true (all players)
emptynet.admin	Reserved for future admin commands	op

How It Works

Server Transfers

This plugin uses Paper's built-in Player#transfer(String host, int port) API to transfer players directly to another server. No proxy or external dependencies are needed - the plugin handles everything internally.

When a player uses /server <name> or a direct command like /lobby, the plugin:

1. Looks up the server configuration
2. Stores the target server as the "last server" for /serverback
3. Starts a transfer timeout monitor (configurable, default 120 seconds)
4. Sends the configured message to the player
5. Transfers the player to the target IP:port

If the player is still on this server after the timeout expires, they are notified that the connection failed and can try again.

Login System

When a player joins, they are prompted to either register or login:

1. New players use /register <password> <confirm-password> to create an account
2. Returning players use /login <password> to authenticate
3. If the player has 2FA enabled, they must then enter /2fa <code>
4. Once authenticated, the player can play normally

While unauthenticated, players cannot:

• Move
• Break or place blocks
• Interact with the world
• Drop items
• Open inventories
• Take damage
• Chat
• Use any commands except /login, /register, and /2fa

Additionally, unauthenticated players receive the blindness effect (configurable with login-blindness). If login-kick-enabled is true, players who don't login/register within login-kick-timeout seconds are kicked from the server.

2FA

Players can enable 2FA after logging in with /2fa set <6-digit-code>. Once enabled, they must enter this code after their password on every login. Use /2fa remove to disable it.

H2 Database

All user accounts are stored in an embedded H2 database at plugins/EmptyNet/emptynet.mv.db. Passwords are stored as BCrypt hashes (never plaintext). The database is automatically created on first run.