Compatibility
Minecraft: Java Edition
Platforms
Supported environments
Links
Tags
Creators
Details
Sol's AuthLogin System
Overview
Sol’s AuthLogin is a powerful and secure authentication system designed for Minecraft servers, now upgraded with a modern token-based auto-login system for improved security and player experience.
Note: Required to install into server/mods folder and is recommended to be installed on client-side as well for auto-login feature & stable authstate restrictions.
Need help, want to suggest a feature, or found a bug?
Join our community to catch exclusive early previews and upcoming changelogs before they go live!
🔐 Key Features
🆕 Secure Token-Based Auto-Login
- Replaces outdated IP-based sessions with a secure token authentication system
- Players receive a unique login token after
/loginor/register - Enables safe and seamless auto-login on future joins
- Falls back to manual login if client mod is not installed
✔ Requires mod on both client & server for full functionality
🔑 Core Authentication System
/register <password> <confirm>— Create a new account/login <password>— Authenticate returning players/change_password <old> <new> <confirm>— Update credentials securely
🛡 Advanced Security Features
- SHA-256 password hashing with per-user unique salt
- Rate limiting to prevent brute-force login attempts
- Temporary account lockout after failed attempts (configurable)
- Multiple session prevention (one account = one player)
- Optional session caching fallback for compatibility
🚫 Strict Pre-Authentication Protection
Until a player is authenticated, they are fully restricted:
- No movement (frozen state)
- No block breaking or placing
- No inventory or container access
- No item pickup
- No combat interaction
- No chat (except auth commands)
- No command usage (except
/login&/register) - Perspective switching is blocked
⏱ Smart Timeout System
- Configurable login timeout with auto-kick
- Grace period before teleporting after login
- Action bar + title reminders at configurable intervals
📍 Spawn & Return System
- Optional spawn teleport on join
- Automatically returns players to their original position after login
- Crash-safe position persistence
- Supports world spawn or custom coordinates
🧩 Admin Commands (/auth_admin)
reload— Reload configurationresetpassword <player> <newPassword>— Reset player passwordunregister <player>— Remove player accountforcelogin <player>— Authenticate player manuallyforcelogout <player>— De-authenticate playerinfo <player>— View auth statuslist— List all registered players
⚙ Highly Configurable
- Authentication timeout & session settings
- Password rules (length, complexity, requirements)
- Fully customizable messages
- Flexible spawn/teleport behavior
🎯 Who Is This For?
✅ Ideal for Offline-Mode (Cracked) Servers
- No Mojang authentication → anyone can use any username
- Prevents account impersonation and griefing
- Ensures only registered users can access their accounts
- Essential for protecting player progress and data
⚠ On Online-Mode Servers
- Mojang already verifies player identity and UUID
- No risk of impersonation
- Using this mod may cause double authentication (Mojang + mod)
👉 Still usable, but generally redundant unless extra security layers are needed
🚀 Why Choose Sol’s AuthLogin?
- Strong protection against common exploits
- Smooth player experience with auto-login
- Built for stability, configurability, and real server environments
Author: Solmochi
Found a bug or have a suggestion? Don't hesitate to leave a comment! I will answer it as fast as I could :)


