> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rimdian.com/llms.txt
> Use this file to discover all available pages before exploring further.

# App extra columns

Apps can extend existing tables with extra columns to store additional data.

## Usage

In your app [manifest.json](/app-manifest-reference), you can define extra columns for a table by adding a `extra_columns` property like this:

```json theme={null}
...
  "extra_columns": [
    {
        "kind": "user",
        "columns": [
            {
                "name": "appx_myapp_column1",
                "type": "varchar",
                "size": 128,
                "is_required": false,
                "description": "Example of extra column in the 'user' table"
            }
        ]
    }
  ]
...
```

The extra columns should follow the [Table Column](/apps-development/app-manifest-reference#table-column) schema.

<Tip>Extra columns are removed from the database when the apps are deleted.</Tip>