Somnium API
by Eclipce77
Somnium API is a Forge library for building custom abilities, stamina systems and per-player progression in Minecraft 1.20.1.
What it does
Powers can be grouped, given configurable conditions for becoming available, and placed in a drag-and-drop ability inventory. A six-slot HUD bar shows the active abilities, with paging and customizable categories.
Abilities draw on a shared stamina resource that drains as powers are used and recovers over time. Overspending triggers the Overuse system, which applies a three-stage penalty to discourage constant ability spam. Composition is a permanent growth stat for each player: it rises through ability use, stamina recovery and surviving overuse, and it expands stamina capacity up to a hard cap.
Addon developers can add Custom Meters for resources such as mana, rage or focus, each with its own drain, regeneration and scaling. Optional per-power XP leveling, tags that gate abilities behind conditions, and optional compatibility with GeckoLib 4, Curios API and Pehkui are included. Somnium API is open source under the GNU General Public License v3.0 only and is published for Forge 1.20.1.
Key features
Five activation types
Powers can be instant, toggled, held, charged or passive, and passive powers can be grouped.
Stamina and Overuse
A shared stamina pool drains with use and recovers over time, and overuse applies a three-stage penalty.
Composition growth
A permanent stat grows with play and raises stamina capacity, with diminishing returns to keep it capped.
Custom meters and transformations
Addon developers can define new resources with their own drain and regeneration, and create shapeshifting abilities with phase transitions.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Who it’s for: Modpack makers and developers who want a shared framework for abilities, stamina and progression on Forge 1.20.1. Players of such packs will need the library installed on the client and the server.
How it compares
Staminus is a client and server Forge mod for 1.20.1 under the MIT License, and it covers stamina alone. Player: Level UP skills is a Forge mod for 1.20.1 – 1.20.6 under the MIT License, focused on skill leveling. Somnium API is limited to Forge 1.20.1 and is open source under the GNU General Public License v3.0 only.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Somnium API | Forge | 1.20.1 | Client and server | 2026-06-02 |
| Staminus | Forge | 1.20.1 | Client and server | 2026-08-20 |
| Player: Level UP skills | Forge | 1.20.1 – 1.20.6 | Client and server | 2026-03-22 |
Questions
Does Somnium API need to be installed on the server?
Which Minecraft versions does Somnium API support?
Which optional mods does Somnium API work with?
In the catalog
Somnium API is one of 3,514 Library mods on ModsFinder, and one of 1,576 Library mods for Forge. 34,764 mods support Minecraft 1.20.1.
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What the author says
A highly customizable Power and Ability API, for those who can dream it possible. Powers & Abilities — A complete ability system with five activation types (Instant, Toggle, Hold, Charged, Passive), groupable into Powers with configurable unlock conditions. Includes a drag-and-drop ability inventory, a 6-slot HUD bar…
Official listing
- Modrinth page
- modrinth.com/mod/somnium-api
- Owner
- Eclipce77
- Published
- 2026-05-09
- Updated on Modrinth
- 2026-06-02
- Facts verified
- 2026-10-15