This mod allows you to create and add items to custom creative tabs, using JSON files inside resource packs. It's aimed at modpack makers and even allows you to disable access to vanilla creative tabs as well as tabs from other mods
This mod is client-side only and is very small in size with no dependencies (other than the Fabric API on Fabric), so you can easily include it inside your modpack.
I recommend checking out the Amended (1.18+) resource pack for a very complete example of what this mod can do.
The configuration of this mod, as well as a couple of examples can be found on the WIKI tab at the top of the page. You can also find pre-made or example packs inside the docs, to help you get started.
Should you need any other assistance, please open a Github Issue or join my discord.
When things go wrong, and they definitely do from time to time, you can open an Issue on Github if it's a bug or suggestion, or for quicker support, you can join our discord and ask your question in the appropriate channel