> For the complete documentation index, see [llms.txt](https://help.inveterate.com/dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.inveterate.com/dev/api-reference-docs/legacy-public-api-reference/free-tiers-api.md).

# Free tiers API

This page covers api endpoints that allow merchants add customers to their free tier membership

To sign up for free tier membership, customer has to be registered in Shopify. 

```typescript
{
    merchantId: string,
    customerId: string,
    segmentId: string?,
}
```

## Sign up customer for free tier

<mark style="color:green;">`POST`</mark> `https://public.inveterateapi.com/signup-free-tier`

#### Request Body

| Name                                         | Type   | Description                                                                                                                                                      |
| -------------------------------------------- | ------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| merchantId<mark style="color:red;">\*</mark> | String | merchantId is the first part of the shop domain. For example if the shop domain is **inveterate-demo.myshopify.com**, Merchant ID is **inveterate-demo**         |
| customerId<mark style="color:red;">\*</mark> | String | Shopify legacy customer IDs with numerical values such as "6412233234" are supported. GraphQL IDs such as  "gid://shopify/Customer/6412233234" are not supported |
| segmentId                                    | String | Optionally provided to specify which free tier the customer is to be enrolled into. If absent, the first free tier to be created is assumed.                     |

{% tabs %}
{% tab title="202: Accepted Successful response" %}

{% endtab %}

{% tab title="400: Bad Request Required body parameters are missing" %}

{% endtab %}

{% tab title="403: Forbidden Free tier is not enabled for the merchant" %}

{% endtab %}
{% endtabs %}