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Implement Passwordless Email Authentication

With an email connection, the user is asked to enter their email address, to which Auth0 sends a one-time code. The user then enters the code into your application.

If the email address attached to the code matches an existing user, Auth0 authenticates the user:

Existing User Flow

If the user is new, their user profile is created for the email connection before they are authenticated by Auth0.

New User Flow

Setup

Configure an email provider

By default, Auth0 sends the email from its own SMTP provider. Auth0's built-in email infrastructure should be used for testing-level emails only. You can configure your own email provider to better monitor and troubleshoot the email service as well as be able to fully customize the emails.

You will need to use your own email provider to be able to modify the From, Subject, and Body of Passwordless emails.

Configure the connection

  1. Navigate to the Connections > Passwordless page in the Auth0 Dashboard, and enable the Email toggle.

Enable Email Passwordless

  1. Select your Email Syntax, and enter your email's From, Subject, and Message text.

Configure Email Passwordless

  1. Enter any Authentication Parameters you would like to include in the generated sign-in link.

  2. Adjust settings for your OTP Expiry and OTP Length, and click SAVE.

If you choose to extend the amount of time it takes for your one-time password to expire, you should also extend the length of the one-time password code. Otherwise, an attacker has a larger window of time to attempt to guess a short code.

Multi-Language Support

The Message area supports multiple languages.

To choose the language, call the /passwordless/start authentication endpoint and set the value of the 'x-request-language' header. When this header is not set, the language is extracted from the 'accept-language' header, which is automatically set by the browser.

Message syntax

The Message area accepts Liquid syntax. You can use this syntax, combined with exposed parameter values, to programmatically construct elements of the message. For example, you can reference the request_language parameter to change the language of the message:

{% if request_language contains 'dutch' %}
   Hier is uw verificatie code: {{ code }}
{% endif %}

{% if request_language contains 'fr-FR' %}
   Ceci est votre code: {{ code }}
{% endif %}

The following parameters are available when defining the message template:

Exposed Parameter Description
code The password to use
link The generated sign-in link
application.name The name of the application with which the user is signing up
request_language The requested language for message content
operation Indicates when the template has been triggered by an update to a user's email via the API. Equals change_email when triggered; otherwise, null.

Enable your apps

Click the Apps tab, and enable the apps for which you would like to use Passwordless Email.

Single-Page Application Tutorials

Regular Web Application Tutorials

Mobile Tutorials