SimpleLogin

A modern, universal authentication and security system for Paper and Velocity. One single JAR file deployed across both platforms for a seamless setup.

SimpleLogin provides a secure, streamlined gateway for offline-mode networks. It automatically detects official Mojang profiles to log them in instantly, while protecting offline-mode connections with secure, secondary BCrypt password authentication.

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Features

• Smart Hybrid Authentication — Automatically validates official Mojang profiles, granting them instant access without requiring secondary registration or login commands.
• Secure Offline Profiles — Protects offline-mode user accounts with industry-standard BCrypt password hashing.
• Session Validation — Secure session persistence using UUID checks to prevent profile spoofing and unauthorized access.
• Virtual Limbo Containment — Full integration with LimboAPI. Unauthenticated players are safely isolated in a lightweight virtual world, preventing them from interacting with the main server worlds or spamming packets until they log in.
• Auto-Dependency Resolution — Automatically downloads and installs the correct LimboAPI plugin version on startup if not present.
• High-Performance Multi-Database — Supports SQLite (out-of-the-box, zero configuration) and MySQL/MariaDB (for multi-server networks) utilizing HikariCP connection pooling.
• Robust Anti-Abuse Shield — Prevents bot attacks and registry spam using connection rate limiters and maximum registration limits per IP.
• Database Backups — Easy administration with /sl backup, /sl backup list, and /sl backup restore commands featuring complete tab completion.
• Full Localization (i18n) — Dynamic language manager supporting English and Spanish out of the box.

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Requirements

• Java: 17 or higher
• Paper: 1.20.4 or higher
• Velocity: 3.3.0 or higher
• LimboAPI: Optional (downloaded automatically if enabled)

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Quick Setup

1. Place the SimpleLogin.jar file in your Velocity plugins/ directory and your Paper backend plugins/ directory.
2. Start the servers to automatically generate the default configuration files.
3. Set online-mode = false in your velocity.toml and your backend servers' server.properties. SimpleLogin dynamically manages the authentication mode per connection.

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Links

• GitHub: https://github.com/ripale22/SimpleLogin
• Issue Tracker: https://github.com/ripale22/SimpleLogin/issues