Just Core
by Yo_Fred
Just Core is a NeoForge library that gives other server mods a shared API, a module registry and an audit log to build on.
What it does
Just Core provides a lightweight, server-side infrastructure layer meant for Vanish Essentials and other future mods. It groups shared contracts, module discovery, player state handling and staff auditing into one core, so each dependent mod can rely on these parts without carrying its own copies. The stable JustCoreApi entry point is the surface that dependent mods call.
Player state is handled through mutable providers, which allow features such as vanish to store and read per-player status. Staff actions are recorded in a central append-only audit log saved to world/justcore/audit.jsonl, and a public StaffActionEvent lets other mods react to those actions. The core runs on NeoForge for 1.21.1 only, and it is published as a server-side mod: players join without installing it, while the server and the mods that depend on it need it. Vanish and Essentials are the dependent mods named by the author.
Installation requires Core 0.2.0 on the server, along with Vanish and Essentials where those are used. The API, module concepts, player states, auditing, events and versioning are documented in the wiki and source code linked from the mod page. The code is not open source; it is released under All rights reserved, so redistribution and modification are not granted by the license.
Key features
Stable API entry point
The JustCoreApi class gives dependent mods one fixed place to access shared services.
Companion-module registry
Companion modules register with the core, which lets the core discover them and keep their contracts in one place.
Mutable player-state providers
Providers hold per-player state that features such as vanish can read and change while the server runs.
Append-only staff audit log
Staff actions are written to world/justcore/audit.jsonl, and each entry is added to the end of the file without rewriting earlier lines.
Public staff action event
A public StaffActionEvent is fired for staff actions, so other mods can respond to them.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
How it compares
Atet's Infrastructure runs on Fabric and NeoForge for 1.21.1 and is server-side only, under All rights reserved, so it can serve similar server roles on both loaders. EaseonSS - Core is Fabric-only, server-side only and under All rights reserved, with files for 1.21.9 – 26.3, a range that does not overlap Just Core's single 1.21.1 target. Create: Compat Core is NeoForge for 1.21.1 like Just Core, but it is a server-side only mod in its own right, so unlike Just Core it is not a client and server mod at all and its environment does not match this one.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Just Core | NeoForge | 1.21.1 | Server-side only | 2026-08-11 |
| Atet's Infrastructure | Fabric and NeoForge | 1.21.1 | Server-side only | 2026-06-13 |
| EaseonSS - Core | Fabric | 1.21.9 – 26.3 | Server-side only | 2026-10-06 |
| Create: Compat Core | NeoForge | 1.21.1 | Client and server | 2025-08-31 |
Questions
Does Just Core need to be installed on the client?
Which dependencies does Just Core need?
Where is the audit log stored?
In the catalog
Just Core is one of 3,514 Library mods on ModsFinder, and one of 1,449 Library mods for NeoForge. 32,366 mods support Minecraft 1.21.1.
More from Yo_Fred
Similar mods
What the author says
Just Core is the server-side API and shared infrastructure layer for Just Vanish, Just Essentials, and future Just mods on Minecraft 1.21.1 with NeoForge. Just Core 0.2.0 is required by Just Vanish 1.3.1+ and Just Essentials 0.3.1+. It keeps shared contracts, module discovery, player states, and staff auditing…
Official listing
- Modrinth page
- modrinth.com/mod/just-core
- Owner
- Yo_Fred
- Published
- 2026-08-09
- Updated on Modrinth
- 2026-08-11
- Facts verified
- 2026-10-15