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

# SMS Subscriptions

These webhooks are sent when a user opts into SMS marketing. Thanx does not
synchronize downstream SMS marketing opt-in status and users are only prompted
to enter a phone number for SMS marketing once. SMS marketing partners are
expected to manage confirmation of SMS marketing consent.

### Payload Description

<ParamField body="user_id" type="string">
  User ID
</ParamField>

<ParamField body="merchant_id" type="string">
  Merchant ID
</ParamField>

<ParamField body="phone" type="string">
  The user's phone number, in E.164 format (eg. `+14157582345`)
</ParamField>

<ParamField body="email" type="string">
  The user's email address
</ParamField>

<ResponseExample>
  ```json theme={null}
  {
    "sms_subscription": {
      "user_id": "woeruijsfwer",
      "merchant_id": "owierywtwt",
      "phone": "+14157582345",
      "email": "example@thanx.com"
    }
  }
  ```
</ResponseExample>