What is SideGate?

SideGate is a Bukkit-compatible plugin (Spigot/Paper/Purpur) for servers that want to keep online-mode=true while still allowing selected non-premium players.

Premium players continue normal Mojang authentication, while approved guest players are handled by SideGate guest flow.

Why use it?

• Keep premium security path for normal players.
• Avoid switching the entire server to offline mode.
• Control exactly who can join as guest.
• Apply clear guest restrictions and visual labels.

Core Features (Current)

• Hybrid Login Flow: Premium users go through standard server authentication; guest candidates use SideGate injection flow.
• Manual Premium Override: premium-usernames always stay in premium path.
• Guest Admission Policy: Use allow-all-guests or allowed-guests.
• Optional Auto-Detect: Mojang API lookup with internal cache (auto-detect-premium).
• Guest Handling: Add guest tag, set gamemode, send title/subtitle/messages.
• Guest Chat Prefix: Prefix applies to players with guest tag only.
• Runtime Reload: /sidegate reload.
• Public API: Addon plugins can integrate via SideGate API service.

Installation

Required dependency: ProtocolLib (SpigotMC)
https://www.spigotmc.org/resources/protocollib.1997/

1. Install ProtocolLib (5.x+).
2. Put the SideGate .jar file in your /plugins folder.
3. Set online-mode=true in server.properties.
4. Start or restart the server.

Configuration Example

# SideGate Configuration

enable-guest-mode: true
auto-detect-premium: true

allow-all-guests: false

premium-usernames:
  - "TamKungZ"

allowed-guests:
  - "FriendName1"
  - "FriendName2"

guest-settings:
  default-gamemode: "SURVIVAL"
  chat-prefix: "&7[Guest] &r"

messages:
  join-title: "&cACCESS RESTRICTED"
  join-subtitle: "&7Guest Mode"
  join-message:
    - "&c=================================="
    - "&6 Welcome to SideGate Protocol"
    - "&7 Account Status: &cGuest (Non-License)"
    - "&7 You have restricted gameplay access."
    - "&c=================================="

Requirements

• Java: 17+
• Server: Spigot / Paper / Purpur (Bukkit-compatible)
• Dependency: ProtocolLib 5.x+ (SpigotMC)

Bug Reports

Submit issues at:
https://github.com/TamKungZ/SideGate/issues

Please include:

• Server software + exact version
• Java version
• ProtocolLib version
• SideGate version
• Relevant startup/login logs

Project Status & License

Closed Source

• Normal server usage is allowed.
• Separate addon plugins using SideGate public API are allowed.
• Modification/redistribution/repackaging of SideGate is not allowed without permission.
• Commercial use or monetization requires prior permission by email: [email protected]

Public reference snapshot:
https://github.com/TamKungZ/SideGate (sidegate-1.0.0-rc.1)

Security Notice

Guest/offline access has impersonation risk. For production servers, use an authentication plugin and strict permission setup.