ModsFinder

JustAuth

by Weldify

JustAuth is a simple player authentication mod for small Better Adventure servers, set up through a shared just.auth file.

FabricClient and serverCustom licenseb1.7.3

What it does

Server owners who run a small Better Adventure server can use JustAuth to restrict who joins. Setup is manual: a folder named justauth holds the configuration, and the host hands each friend a file called just.auth to place in their .minecraft folder. Only players holding that file are meant to get in, which suits a closed group rather than a public server.

The mod is written for Fabric and targets Minecraft b1.7.3. A server running it needs every connecting player to have it too. The author states the mod was tested on 7.3 03 and is probably compatible with many other versions, but no other builds are listed. Snapshot builds are published. The code is released under a custom license, and the public source code and issue tracker are linked from the project page.

Key features

  1. Player authentication

    Restricts server access to players who have been given the matching authentication file.

  2. Access file handoff

    The host copies a just.auth file that a player renames and places in their client folder to get in.

  3. Closed group gating

    Gates a small Better Adventure world so that only the players holding the file can join.

No per-version build data
Modrinth lists game versions for this project (b1.7.3), but the source data has no build per game version and loader, so the compatibility grid is not shown.

Use cases

Closed friend servers

A host running a small Better Adventure world for a known group can give each member the access file directly.

Who it’s for: Server owners and small groups who want a simple gate on a Better Adventure server, and who are comfortable with manual file sharing rather than an account system.

How it compares

Full comparison

Server List Password Mod is a client and server Fabric mod under the MIT License, not open source, covering 1.21.1 – 1.21.11, and asks for a password instead of a shared file. JustAuth also works on client and server, but it is released under its custom license and targets b1.7.3 only.

ModLoadersGame versionsEnvironmentUpdated
JustAuthFabricb1.7.3Client and server2025-05-06
Server List Password ModFabric1.21.1 – 1.21.11Client and server2026-07-16

Questions

Does JustAuth have to be installed on both sides?

Yes. Every player and the server need a copy of the mod.

How does a player get access to the server?

The host copies the just.auth file and gives it to the player, who renames it if needed and places it in their .minecraft folder.

Which Minecraft versions does JustAuth support?

The only listed build targets b1.7.3. The author tested it on 7.3 03 and says other versions are probably compatible, but none are confirmed.

In the catalog

JustAuth is one of 8,016 Management mods on ModsFinder, and one of 5,930 Management mods for Fabric. 567 mods support Minecraft b1.7.3.

Management mods8,016Fabric modsMods for b1.7.3567

Similar mods

Mod Loading Screenrd-132211 – 26.3BH Creativeb1.7.3BetterF3 StationAPIb1.7.3BetaLAN StationAPIb1.7.3MineGITb1.5 – 26.3JAJavaProgArgOverrideb1.7.3 – 26.3

What the author says

Simple player authentication mod for small Better than Adventure servers. Tested on 7.3_03 but it's probably compatible with a whole bunch of other versions too!
Weldify, on the Modrinth page

Official listing

Owner
Weldify
Published
2025-05-06
Updated on Modrinth
2025-05-06
Facts verified
2026-10-15

Tags

Management
Open on ModrinthCompare