AuthCore
AuthCore is a Fabric login security framework for offline-mode servers, guarding player accounts against bots and griefers.
What it does
On servers running in offline mode, AuthCore manages player sessions and login checks so that automated clients and bots have a harder time getting in. Its layered defense covers password hashing with Argon2id, BCrypt and SCRAM, risk-based physical action captchas, brute-force lockouts, honeypots, and a token-authenticated HTTPS REST web admin panel.
The mod detects whether a server runs in online or offline mode from server.properties, and a background Mojang verification lets verified premium players join without a password while offline or cracked players authenticate. It is aimed at server owners who run Minecraft without Mojang account checks. Fabric API is required, and the server must run the mod; the environment is server-side only, so players join without installing anything.
Files cover Minecraft 1.16 – 26.3 in 40 release versions, with one jar for Fabric, Forge and NeoForge builds. The code is open source under the CC0 1.0 Universal license, and a source code repository, issue tracker and wiki are linked from its listing. The mod was first published on 2026-02-08 and last updated on 2026-09-24.
Key features
Layered login defense
Seven defense layers combine password hashing, captchas, lockouts and honeypots to block automated clients.
Password hashing options
Passwords can be stored with Argon2id, BCrypt or SCRAM hashing.
Web admin panel
A REST web admin panel served over HTTPS is protected by token authentication.
Session handling under load
Player lookups use UUID-keyed lockless caches with bounded LRU storage and lazy database fetching, which keeps resource use steady during join bursts.
Gallery
Compatibility
Latest build for each game version and loader.
26.x5 of 5 versions with builds
1.21.x12 of 12 versions with builds
1.20.x7 of 7 versions with builds
1.19.x5 of 5 versions with builds
1.18.x3 of 3 versions with builds
1.17.x2 of 2 versions with builds
1.16.x6 of 6 versions with builds
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
Who it’s for: Server owners who run offline-mode or cracked servers and want login checks, lockouts and an admin panel, without changing the client.
How it compares
Sol's AuthLogin is a Forge and NeoForge mod for 1.16.5 – 1.21.1, server required and client optional, and it is not open source under All rights reserved. SafeAuth is a client-side only MIT License mod for 1.16.5 – 26.2 across Fabric, Forge, NeoForge and Quilt, and it is not open source. Login System is a server-side only MIT License mod for Fabric, Forge and NeoForge, and it is open source for 1.20 – 26.2.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| AuthCore | Fabric, Forge and NeoForge | 1.16 – 26.3 | Server-side only | 2026-09-24 |
| Sol's AuthLogin | Forge and NeoForge | 1.16.5 – 1.21.1 | Server required, client optional | 2026-08-10 |
| SafeAuth | Fabric, Forge, NeoForge and Quilt | 1.16.5 – 26.2 | Client-side only | 2026-07-27 |
| Login System | Fabric, Forge and NeoForge | 1.20 – 26.2 | Server-side only | 2026-08-24 |
Questions
Does AuthCore need Fabric API?
Do players need to install AuthCore?
Does AuthCore work on Forge and NeoForge?
In the catalog
AuthCore is one of 8,016 Management mods on ModsFinder, and one of 5,930 Management mods for Fabric. 8,071 mods support Minecraft 26.3.
Similar mods
What the author says
The Fortress Framework for Minecraft Servers. One unified codebase for 1.16.0 → 26.x+ on Fabric, Forge, and NeoForge. Hardened against every attack scenario, race-condition-free under burst load, and engineered to hold 500k+ registered accounts and thousands of concurrent players with flat, spike-free resource usage.
Official listing
- Modrinth page
- modrinth.com/mod/authcore
- Owner
- PotenFYR Studios
- Published
- 2026-02-08
- Updated on Modrinth
- 2026-09-24
- Facts verified
- 2026-10-15