S-Lib
by Stalemated
S-Lib is a configuration and utility library for Minecraft mods, and mod authors use it to read and write settings from a config class.
What it does
Settings are declared as fields in a config class. The library manages the file on disk, so a mod built on it does not need its own loader and saver code. Newly added fields receive their default values automatically, obsolete keys are removed, and numeric values are clamped to a range when the @RangeInt, @RangeFloat or @RangeDouble annotation is placed on the field.
Each config option can be synchronized in one of three ways. A server-authoritative setting overrides the client and is broadcast on login and updated in real time, with permission checks such as operator-only access. A local setting can inform the server of changes, or remain purely local without any network sync. Configuration files are backed up automatically when corruption or invalid syntax is detected, which preserves a broken file after an accidental edit.
S-Lib is distributed for Fabric, Forge and NeoForge as client-side only, so it runs in single-player and multiplayer clients. Its source code is open source under the MIT License. Its files target game versions 1.20.1 and 1.21.1, and a 1.21.1 build is published for each loader, with the latest files dated 2026-09-30.
Key features
Server-authoritative sync
A config option can be set by the server and pushed to connected clients on login, then updated live as the server changes it.
Permission checks
Synchronized options can require a permission check, such as operator-only, before a change is accepted.
Range annotations
The @RangeInt, @RangeFloat and @RangeDouble annotations clamp a value to the bounds declared on its field.
Inline comments
The @Comment annotation places a comment above a field directly in the config class, and the comment is written to the file.
Automatic backups
A backup is created when a config file is corrupted or has invalid syntax, so the broken version is kept for inspection.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Required by 6 mods
Use cases
Mod configuration
A mod author can declare settings in one class and let the library handle loading, defaults and file repair.
Shared server settings
A server can keep an option authoritative and let players see its current value without editing their own files.
Who it’s for: Mod developers who need typed, self-repairing config files, and server owners who want certain settings controlled from the server side.
How it compares
Admiral is server-side only and is published for Fabric, Forge and NeoForge across 1.19 – 26.3, so it covers a wider version span than S-Lib. Anno is a client and server library for Fabric only, built for 1.18.2 – 1.21.1. SekCore Lib requires both sides too, for Forge and NeoForge, with files for 1.18.2 – 1.20.1. RecipeSync is NeoForge only, for 26.1.2, and both sides need it.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| S-Lib | Fabric, Forge and NeoForge | 1.20.1 – 1.21.1 | Client-side only | 2026-09-30 |
| Admiral | Fabric, Forge and NeoForge | 1.19 – 26.3 | Server-side only | 2026-09-19 |
| Anno | Fabric | 1.18.2 – 1.21.1 | Client and server | 2025-01-28 |
| SekCore Lib | Forge and NeoForge | 1.18.2 – 1.20.1 | Client and server | 2023-06-22 |
| RecipeSync | NeoForge | 26.1.2 | Client and server | 2026-04-24 |
Questions
Does S-Lib need to be installed on the server?
Which loaders does S-Lib support?
Which mods depend on S-Lib?
In the catalog
S-Lib 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 Stalemated
Similar mods
What the author says
S-Lib is a lightweight utility and config library for Minecraft modding.
Official listing
- Modrinth page
- modrinth.com/mod/s-lib
- Owner
- Stalemated
- Published
- 2026-06-15
- Updated on Modrinth
- 2026-09-30
- Facts verified
- 2026-10-15