Register and Login Plugin

# Register And Login Plugin
Lightweight offline‑mode server registration & login plugin to prevent account theft on offline servers.

Discord showcase

✨ Features

1. Registration System
   Command: /register <password> <confirmPassword>
   Unregistered players cannot move or chat, and may only run the register command. The two entered passwords must match. Players will be logged in automatically upon successful registration.

2. Login System
   Command: /login <password>
   Registered players join the server in a locked state, unable to move or chat. All restrictions will be lifted after entering the correct password.
   OPs can run /login update to check for new versions on Modrinth. Tab‑completion for update is only visible to operators.

3. Change Password
   Command: /changepassword <oldPassword> <newPassword>
   Players must log in first before modifying their password.

4. Persistent Data Storage
   Player accounts and passwords are saved at plugins/RegisterAndLoginPlugin/accounts/PlayerUUID.txt.
   Account files use player UUID as filename, so accounts will not be lost even if players change their in‑game username. All data survives server restarts.

5. Security Protection
   Players will be kicked if they fail to log in within 60 seconds after joining. Passwords are stored as SHA‑256 hashes instead of plain text.

6. Customizable Messages
   All in‑game messages can be modified inside lang.yml.

⚙️ Supported Servers

Paper 1.21.x
Purpur 1.21.x
Not compatible with Spigot, Fabric.

🎉 Version Changelog

v1.0.1: Added password hash encryption
v1.2.0: Added /changepassword command; Added OP‑only /login update version checker; Added tab‑completion for /login update (only visible to operators); Code optimization.

Planned features: 2‑day auto‑login for offline players.

📂 Open Source Information

This project is open‑sourced under the MIT License
Source Repository:
Feedback and pull requests are welcome to improve this plugin.