OfflineAuth
by YuWan030
OfflineAuth lets a Forge server require players with offline UUIDs to register and log in before they can play, backing up and restoring their inventory in the meantime.
What it does
Players on an offline-mode server can register and log in with a password, and OfflineAuth holds back their actions until they do. The inventory of an unauthenticated player is saved and restored once they log in, so items are not lost or exposed while the login is pending. IP auto-login lets a player who signs in from the same address skip the prompt for a set time window after their last session.
Brute-force protection counts failed password attempts and locks an account for a configurable period, after which the player is kicked. The mod is server-side only: players join without installing anything, and the server alone runs it. Installation requires TrueUUID, which the server uses to tell offline UUID players apart from premium accounts. Online premium accounts are not affected, since only offline UUID players go through this flow.
The mod is released under the GNU Lesser General Public License v3.0 only, and the source code and issue tracker are public. Files are published for Forge across six release versions, 1.20.1 – 1.20.6, with 1.0.3 for 1.20.6 as the latest, dated 2025-10-31.
Key features
Registration and login
Players register with a password and log in with register, login and change-password commands.
Inventory protection
Items held by a player who has not logged in are kept safe and returned once the login succeeds.
Brute-force lockout
Repeated wrong passwords trigger a timed lock on the account, and the player is removed from the server.
IP auto-login
A returning player on the same IP is logged in automatically within a set time window.
Help command
The auth help command lists the commands available to the player.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Offline-mode servers
Servers that accept offline UUID accounts can require a password before play starts.
Who it’s for: Server owners running offline-mode servers who want players to prove ownership of a name. Players only need to know their password; no client install is involved.
How it compares
SAuth is server-side only on Forge for 1.20.1, released under the MIT License. LTS Auth is also server-side only and Forge 1.20.1, but its license is All rights reserved, so it is not open source. OfflineAuth covers 1.20.1 – 1.20.6 under the GNU Lesser General Public License v3.0 only.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| OfflineAuth | Forge | 1.20.1 – 1.20.6 | Server-side only | 2025-10-31 |
| SAuth | Forge | 1.20.1 | Server-side only | 2025-10-05 |
| LTS Auth | Forge | 1.20.1 | Server-side only | 2026-06-18 |
Questions
Does OfflineAuth need TrueUUID?
Does OfflineAuth have to be installed on the client?
Does OfflineAuth affect premium accounts?
More from YuWan030
What the author says
A lightweight authentication mod for Minecraft servers. Supports registration, login, inventory protection, brute-force prevention, and auto-login based on IP.
Official listing
- Modrinth page
- modrinth.com/mod/offlineauth
- Owner
- YuWan030
- Published
- 2025-09-08
- Updated on Modrinth
- 2025-10-31
- Facts verified
- 2026-10-15