> For the complete documentation index, see [llms.txt](https://jugandomiguel.gitbook.io/custom-resource-pack-geysermc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jugandomiguel.gitbook.io/custom-resource-pack-geysermc/custom-mappings/create-the-mapping-file.md).

# Create the mapping file

You need to create a file with whatever name you want with extension .json like this:

`my_custom_armor.json`

In the file you can add different option depending of what you want to change, you can see the options [here](https://wiki.geysermc.org/geyser/custom-items/).

We recommend you to use the options we are going to put as default. To start now you need to go to the folder of geysermc in your server, the path should be something like this:

`my-server/plugins/`Geyser-Spigot`/custom_mappings` there you need to create the file for your custom thing. If you <mark style="color:red;">**DON'T**</mark> have geysermc you should see how to install everything [here](/custom-resource-pack-geysermc/general/installs.md).

***

In the custom mappings create the .json file and add the next code:

```json
{
    "format_version": 1,
    "items": {
        "minecraft:the-minecraft-item-name": [
            {
                "name": "your_item_name",
                "custom_model_data": 10000,
                "display_name": "§eThe display name of you item",
                "is_tool": false,
                "is_hat": false,
                "texture_size": 16                
            }
        ]             
    }
}
```

{% hint style="warning" %}
IMPORTANT: The custom\_model\_data need to be the same as the item in Minecraft Java
{% endhint %}

In the first section you need to specify what type or item you're going to create, for that see the list here:

{% content-ref url="/pages/JftxvGXfyCvS32mVL200" %}
[List of mappings](/custom-resource-pack-geysermc/custom-mappings/create-the-mapping-file/list-of-mappings.md)
{% endcontent-ref %}