> ## Documentation Index
> Fetch the complete documentation index at: https://docs-staging-fix-docs-5525.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Sample Use Cases: Actions with Passwordless Authentication

> Learn how to use Actions to customize passwordless authentication flows, including routing SMS and email OTPs through custom providers.

With [Actions](/docs/customize/actions/actions-overview), you can extend [passwordless connections](/docs/authenticate/passwordless) by routing SMS and email OTP delivery through custom providers. Auth0 Actions give you control over which phone and email services handle your authentication messages.

## Send passwordless email with a custom email provider

When a user [authenticates through a passwordless email connection](/docs/authenticate/passwordless/authentication-methods/email-otp), Auth0 triggers the `custom-email-provider` Action to deliver the OTP. Use this Action to route messages through any email service.

To configure the Action, navigate to [**Branding > Email Provider**](https://manage.auth0.com/#/templates/provider) and select the **Custom Provider** option. To learn more, read [Configure an Email Provider with a Customized Action](/docs/customize/email/smtp-email-providers/custom/configure-action).

```javascript lines theme={null}
/**
 * Handler called when Auth0 needs to deliver a passwordless email OTP.
 * @param {Event} event - Details about the notification.
 * @param {CustomEmailProviderAPI} api - Methods for controlling notification behavior.
 */
exports.onExecuteCustomEmailProvider = async (event, api) => {
  try {
    const response = await fetch('https://api.example.com/send-email', {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${event.secrets.API_KEY}`,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        to: event.notification.to,
        from: event.notification.from,
        subject: event.notification.subject,
        html: event.notification.html,
        text: event.notification.text,
      }),
    });

    if (response.status >= 500) {
      api.notification.retry(`Server error from email provider: ${response.status}`);
      return;
    }
  } catch (error) {
    api.notification.drop(`Unexpected error: ${error.message}`);
  }
};
```

To learn more about available event properties, read [Actions Triggers: custom-email-provider - Event Object](/docs/customize/email/smtp-email-providers/custom/action-triggers-custom-email-provider-event-object).

## Send passwordless SMS with a custom phone provider

When a user [authenticates through a passwordless SMS connection](/docs/authenticate/passwordless/authentication-methods/sms-otp), Auth0 triggers the `custom-phone-provider` Action to deliver the OTP. Use this Action to route messages through any SMS provider.

To configure the Action, navigate to [**Branding > Phone Provider**](https://manage.auth0.com/dashboard/#/phone/templates/phone/provider) and select the **Custom** option. To learn more, read [Configure a Custom Phone Provider](/docs/customize/phone-messages/configure-phone-messaging-providers/configure-a-custom-phone-provider).

```javascript lines theme={null}
/**
 * Handler called when Auth0 needs to deliver a passwordless SMS OTP.
 * @param {Event} event - Details about the notification.
 * @param {CustomPhoneProviderAPI} api - Methods for controlling notification behavior.
 */
exports.onExecuteCustomPhoneProvider = async (event, api) => {
  const response = await fetch('https://api.example.com/messages', {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${event.secrets.API_KEY}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      to: event.notification.recipient,
      from: event.notification.from,
      body: event.notification.as_text,
    }),
  });

  if (!response.ok) {
    api.notification.retry(`Failed to send SMS: ${response.status}`);
  }
};
```

To learn more about available event properties, read [Actions Triggers: custom-phone-provider - Event Object](/docs/customize/phone-messages/configure-phone-messaging-providers/configure-a-custom-phone-provider/actions-triggers-custom-phone-provider-event-object).

## Learn more

* [Configure an Email Provider with a Customized Action](/docs/customize/email/smtp-email-providers/custom/configure-action)
* [Configure a Custom Phone Provider](/docs/customize/phone-messages/configure-phone-messaging-providers/configure-a-custom-phone-provider)
* [Configure a Custom Phone Provider with Twilio Verify](/docs/customize/phone-messages/configure-phone-messaging-providers/configure-a-custom-phone-provider/configure-a-custom-phone-provider-with-twilio-verify)
* [Set Up Custom SMS Gateway for Passwordless Connections](/docs/authenticate/passwordless/authentication-methods/use-sms-gateway-passwordless)
* [Use the Unified Phone Experience for Passwordless](/docs/customize/phone-messages/unified-phone/unified-phone-experience-passwordless)
* [Passwordless Connections Best Practices](/docs/authenticate/passwordless/best-practices)