# Add subscribers to a Klaviyo list

> Formspree Docs · Using the CLI · Updated July 14, 2023

The **subscribe profile** action subscribes a profile in a Klaviyo list. Under the hood, this action calls the [subscribe profiles to list](https://developers.klaviyo.com/en/reference/subscribe) API endpoint. If the call fails, we'll retry it for you.

Adding the **subscribe profile** action in the `formspree.json` file has the same effect as adding the Klaviyo plugin in the Formspree dashboard. See the Klaviyo plugin help article for more information. 

## Formspree.json configuration

| Key | Type | Description |
| --- | --- | --- |
| `app` |  String | Must be `klaviyo` |
| `type`  |  String | Must be `addSubscriber` |
| `listName` |  String | Your Klaviyo list name. Should be exactly the name case sensitive. |
| `apiKey` |  String | Your API key (must be a $ env variable reference, required) |
| `defaultPhoneRegion` |  String | Optional. Country ISO Code to complete phone numbers with Country Phone Code. Check out the [Klaviyo docs](/articles/plugins/adding-subscribers-to-klaviyo-list/) at phone section for more information. |

**Example**

```javascript
{
  "forms": {
    "contact": {
      "name": "Contact Form",
      "actions": [
        {
          "app": "klaviyo",
          "type": "addSubscriber",
          "listName": "Newsletter",
          "defaultPhoneRegion": "US",
          "apiKey": "$KLAVIYO_API_KEY"
        }
      ]
    }
  }
}
```

## Validation rules

The **add or update contact** action adds the following validation rules implicitly:

| Field | Validation Rule |
| --- | --- |
| `email` | Required |
| `email` | Type is `email` |