HotbarAPI
by Sygikal
With HotbarAPI installed, a mod can highlight hotbar slots by an integer value on each item, and clients can receive custom status bars.
What it does
HotbarAPI is a Fabric library that lets other mods register Status Bars and attach them to hotbar slots. Registration can be partly driven by data, and a slot can be highlighted according to an integer that the item carries. The API is used on the client, so a client mod can receive the custom status bars even when the server has them registered.
Players need the mod on their client, while a server can add it for extra features and does not have to run it. It depends on UltraLib, which has to be installed alongside it. HotbarAPI is published for Fabric only, for game versions 1.20.1 – 1.21.10, and the latest file is 1.5.0+1.21.9 for 1.21.10, released on 2025-10-01. The code is not open source; the mod is released under All rights reserved.
Key features
Status Bars on the hotbar
Status Bars are drawn over hotbar slots, so a value can be read without opening an inventory screen.
Integer-based highlighting
Hotbar slots can be highlighted according to an integer tied to the item, letting other mods show changing states.
Partly data-driven registration
Status Bars can be registered in part through data, which cuts down on the code a mod needs to add its own bars.
Client-side status bars
Clients can receive custom status bars even when the server still registers them, so the server does not need the same build.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Required by 1 mod
Use cases
Compatibility with other mods
HotbarAPI Compatibility is the recommended companion for combining HotbarAPI with other mods.
Who it’s for: Mod developers who want to show item-based state on the hotbar, and players who run such mods on a client.
How it compares
Better Highlighting is a Fabric client-side mod for 1.20.1 – 26.3 under the GNU General Public License v3.0 only, and it is open source. Configured Keep Inventory is server-side only, is not open source, and covers 1.20.1 – 1.21.1 under All rights reserved.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| HotbarAPI | Fabric | 1.20.1 – 1.21.10 | Client required, server optional | 2025-10-01 |
| Better Highlighting | Fabric | 1.20.1 – 26.3 | Client-side only | 2026-09-22 |
| Configured Keep Inventory | Fabric | 1.20.1 – 1.21.1 | Server-side only | 2026-06-18 |
Questions
Does HotbarAPI need UltraLib?
Does HotbarAPI have to be installed on the server?
Which game versions does HotbarAPI support?
In the catalog
HotbarAPI is one of 3,514 Library mods on ModsFinder, and one of 2,348 Library mods for Fabric. 15,569 mods support Minecraft 1.21.10.
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What the author says
HotbarAPI is an API that: - Allows easy partially-data-driven registration of Status Bars. - Allows highlighting hotbar slots based on integer or item. (Unsupported on 1.21.6) - more soon™ HotbarAPI can be used as a client side mod, or can receive custom status bars from the server (but they still have to be…
Official listing
- Modrinth page
- modrinth.com/mod/hotbarapi
- Owner
- Sygikal
- Published
- 2025-05-26
- Updated on Modrinth
- 2025-10-01
- Facts verified
- 2026-10-15