minecraft-kajetans-mod/src/main/resources/data/km/recipes/armor/cloth_chestplate.json

{
    "type": "minecraft:crafting_shaped",
    "pattern": [
        "X X",
        "XXX",
        "XXX"
    ],
    "key": {
        "X": {
            "item": "km:cloth"
        }
    },
    "result": {
        "item": "km:cloth_chestplate"
    }
}