Passwordless Authentication with a magic link via e-mail on Regular Web Apps

Instead of sending the user a one time code, you can configure Auth0 to send a magic link:

Auth0 will send an email containing a clickable button or link:

After clicking the button, the user will be automatically signed-in to your application:

Setup

1. Optional: Configure an email provider

By default, Auth0 sends the email from its own messaging provider. Optionally, you can configure your own email provider to better monitor and troubleshoot the email service.

2. Configure the connection

In the Dashboard, on the Email page, under Connections > Passwordless, you can configure the contents and behavior of the email.

Multi-Language Support

The Message area supports usage of multiple languages.

By making a call to the /passwordless/start authentication endpoint, you can set the value of an 'x-request-language' header to the language of your choice. If the value of this header is not set, the language will be extracted from the value in the 'accept-language' header that is automatically set by the browser.

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 template:

Exposed Parameter Description
code the password to use
link the magic link
application.name the name of the application name where the user is signing up
request_language the requested language for the message content
operation equals change_email when the template is triggered by an update to a user's email via the API, otherwise null

4. Configure Callback URL

For security purposes, you must to add the callback URL to the list of Allowed callback URLs in your app's Settings Section of the Dashboard.

Implementation

Use Lock (the Auth0 UI widget)

Auth0 Lock Passwordless is a professional-looking dialog that allows users to log in after receiving a one-time password via email or text message.

After installing Lock Passwordless, you must initialize it with your Client Id and domain. You can find this information on your application settings page.

Then you can trigger the login using the callbackURL option to specify the endpoint that will handle the authentication on the server-side:

<script src="https://cdn.auth0.com/js/lock-passwordless-2.2.min.js"></script>
<script type="text/javascript">
  function login(){
    // Initialize Passwordless Lock instance
    var lock = new Auth0LockPasswordless('YOUR_CLIENT_ID', 'YOUR_AUTH0_DOMAIN');
    // Open Lock in SMS mode
    lock.magiclink( {callbackURL: 'https://YOUR_APP/callback'} );
  }
</script>
<a href="javascript:login()">Login</a>

This will open a dialog that asks the user for their email address.

Then Auth0 will send an email to the user containing the magic link. After clicking the link, the user will be signed in to your application automatically and redirected to the specified callbackURL.

You can follow any of the Regular Web App Quickstarts to see how to handle the authentication callback server side. A sample application is available in the Node.js Passwordless Authentication repository on GitHub.

Use your own UI

Sample Project

Download a sample project specific to this tutorial configured with your Auth0 API Keys.

You can perform passwordless authentication in your regular web app with your own custom UI using the Auth0 JavaScript client library.

Construct a new instance of the Auth0 client as follows:

<script src="https://cdn.auth0.com/js/auth0/8.9/auth0.min.js"></script>
<script type="text/javascript">
  var webAuth = new auth0.WebAuth({
    domain:       'YOUR_AUTH0_DOMAIN',
    clientID:     'YOUR_CLIENT_ID',
    redirectUri: 'https://YOUR_APP/callback'
  });
</script>

You must provide a way for the user to enter an email to which the magic link will be sent. Then you can begin the passwordless authentication as follows (assuming the name of your form input as input.email):

function sendEmail(){
  var email = $('input.email').val();

  webAuth.passwordlessStart({
    connection: 'email',
    send: 'link',
    email: email
  }, function (err,res) {
    if (err) {
      // Handle error
    }
    // Hide the input and show a "Check your email for your login link!" screen
    $('.enter-email').hide();
    $('.check-email').show();
  });
}

This will send an email containing the magic link. After clicking the link, the user will be automatically signed in and redirected to the redirectUri which can be specified in the Auth0 constructor.

Check out the Auth0.js SDK reference documentation for more information.