What JamLib works with.
| Platform | Java Edition |
|---|---|
| Loaders | Fabric, NeoForge, Quilt, Forge |
| Minecraft versions | 1.18, 1.18.2, 1.19.4, 1.20.6, 1.21.11, 26.1.2, 26.2, 26.3 |
| Environment | Client, Server |
JamLib is a Java library mod that every mod from Jam Core builds on. It ships for Fabric, NeoForge, Quilt and Forge, and it must be installed on both sides of a multiplayer setup. It does nothing on its own, so you add it when another mod asks for it.
Loaders and versions
- Fabric: Minecraft 1.18 to 26.3. The newest build requires Fabric API; some builds for 1.20.1 to 1.21.11 require Fabric API and Architectury API; some builds for 1.18 to 1.20.2 need no dependencies.
- NeoForge: Minecraft 1.20.2 to 26.3. The newest build needs no dependencies; some builds for 1.20.2 to 1.21.11 require Architectury API.
- Quilt: Minecraft 1.18 to 26.2. The newest build requires Fabric API; some builds for 1.20.1 to 1.21.11 require Fabric API and Architectury API; some builds for 1.20.2 to 1.20.4 require Architectury API and Quilted Fabric API (QFAPI) / Quilt Standard Libraries (QSL); some builds for 1.18 to 1.20.2 need no dependencies.
- Forge: Minecraft 1.20.1 to 1.20.4. The newest build requires Architectury API; some builds for 1.20.2 need no dependencies.
What JamLib provides
The library is platform-agnostic and Architectury based. Mod authors get a shared toolkit instead of rewriting the same plumbing for each loader.
- Platform abstractions that hide loader differences.
- Events for mods to hook into.
- A JSON5 config API.
- Networking helpers.
- A mod repost (9minecraft etc.) checker.
How to install JamLib
- 1.Install the loader that matches your mod, using the guide to installing Fabric or the guide to Forge and NeoForge.
- 2.Pick the JamLib file for your loader and game release, then check the dependency list above.
- 3.Put the JamLib file and each required dependency, such as Fabric API or Architectury API, into the mods folder.
- 4.Launch with the loader's profile. Repeat the same steps on the host of any multiplayer session.
Trade-offs
JamLib adds no gameplay, blocks or items. Its value is indirect, and dependency needs shift between releases, so older files may want Architectury API while the newest Fabric and Quilt files want Fabric API. Forge coverage is the narrowest of the four loaders, so check that your loader has a file for your release before you commit to a dependent mod.
Questions about JamLib.
4 questions
What is JamLib used for?
JamLib is a shared library for mods made by Jam Core. It supplies platform abstractions, events, networking, a JSON5 config API and a repost checker. Players install it only because another mod lists it as a requirement.
Do I need JamLib on both sides of a multiplayer session?
Yes. JamLib is listed as required for players and for the host of a multiplayer session, so it needs to be installed on both sides. It adds no gameplay on its own, so add it whenever another mod asks for it, and pick the file that matches your loader and release.
Does JamLib work on Forge and NeoForge?
It does. JamLib publishes files for Forge and NeoForge as well as Fabric and Quilt. Forge has the smallest range of releases, so confirm a file exists for your release before choosing that loader.
Is JamLib open source?
Yes. The source is on GitHub under JamCoreModding, and the repository's LICENSE file contains MIT permission text with Jamalam's 2026 copyright. You are free to use, modify and distribute it under those terms.
