# Custom Checkboxes

This page describes how to add a custom checkbox to the Kustom Checkout (KCO) process.  This allows for features like newsletter opt-ins during checkout.

## How it's Done

To add a custom checkbox, include a `checkbox` object within the `options` part of the order creation call.  The checkbox's text can be defined using Markdown formatting (e.g., `[link text](checkboxes/url.md)`).

The status of the checkbox can be retrieved via the `merchant_requested` object in a Retrieve Order call or through the `checkbox_change` event.  More details on the checkbox object are in the API Reference.


```json
{
  //...
  "options": {
    "additional_checkbox": {
      "text": "Lorem ipsum dollar sit amet. [Link](https://kustom.co)",
      "checked": true,
      "required": false
    }
  }
}
```

When reading the order from the API, the `additional_checkbox` field within the `merchant_requested` object will be `true` if the checkbox was checked.


```json
{
  "merchant_requested": {
    "additional_checkbox": true
  }
}
```