HZLib
by Heria Zone
HZLib is a shared library from Heria Zone that supplies common code to the team's other mods, so the logic is written once for Fabric, Forge and NeoForge.
What it does
HZLib provides a loader-agnostic foundation: an entity framework with base entity types, feature composition, stat configuration and variant management, a data-driven animation profile system shared across entity types, and platform services for registration, configuration, events and networking, abstracted per loader. Its author describes it as the engine underneath Heria Zone mods rather than a standalone feature set. Players do not interact with it directly; it adds no items or blocks of its own.
The library requires no other mod and is open source under the GNU Lesser General Public License v3.0 only. A server running it needs every connecting player to have it too. Lovely Robot: Legacy requires it. Files for 1.21.1 are published for Fabric, Forge and NeoForge, first published 2026-06-17 and last updated 2026-07-04, with a 1.21.1-1.0.0 build on each loader.
Key features
Entity framework
Base entity types with composable features, stat configuration and variant management for mods built on the library.
Animation profiles
Animation definitions are declared as data and reused across different entity types.
Variant registration
Texture, model, size and animation variants are registered through a single system.
Platform services
Registration, configuration, events and networking are abstracted so one codebase serves all three loaders.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Required by 1 mod
Use cases
Who it’s for: Mod developers who want to build on Heria Zone's shared code, and players who run Lovely Robot: Legacy, which depends on it.
How it compares
Zones API is a Fabric-only, server-side mod under the MIT License with files for 1.21.8, so it covers a different loader and version. Matthiesen Core is open source under the MIT License and is published for Fabric and NeoForge on 1.21.1, where HZLib also has a Fabric build, but it lacks a Forge file.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| HZLib | Fabric, Forge and NeoForge | 1.21.1 | Client and server | 2026-07-04 |
| Zones API | Fabric | 1.21.8 | Server-side only | 2025-08-06 |
| Matthiesen Core | Fabric and NeoForge | 1.21.1 | Client and server | 2026-09-15 |
Questions
Which loaders does HZLib support?
Does HZLib have to be installed on both sides?
Which mod requires HZLib?
In the catalog
HZLib is one of 3,514 Library mods on ModsFinder, and one of 2,348 Library mods for Fabric. 32,366 mods support Minecraft 1.21.1.
More from Heria Zone
Similar mods
What the author says
HZLib is the shared library powering Heria Zone's mod ecosystem. It provides the loader-agnostic foundation that all Heria Zone mods are built on — so that common logic is written once, maintained once, and works across Forge, NeoForge, and Fabric without duplication. If you're playing a Heria Zone mod, this is the…
Official listing
- Modrinth page
- modrinth.com/mod/hzlib
- Owner
- Heria Zone
- Published
- 2026-06-17
- Updated on Modrinth
- 2026-07-04
- Facts verified
- 2026-10-15