Dehydration is an thirst mod.

Dehydration is a mod built for the Fabric Loader. It requires Fabric API and Cloth Config API to be installed separately; all other dependencies are installed with the mod.

Dehydration is licensed under GPLv3.

You can set hydration for items via a datapack. Custom mod items might need to use the dehydration api, check out the DehydrationAPI.class
If you don't know how to create a datapack check out Data Pack Wiki website and try to create your first one for the vanilla game.
If you know how to create one, the folder path has to be data\dehydration\hydration_items\YOURFILE.json
An example for giving an item hydration can be found below:

{
    "1": {
        "replace": false,
        "items": [
            "minecraft:melon_slice"
        ]
    },
    "2": {
        "replace": false,
        "items": [
            "minecraft:potion"
        ]
}