Lock Passwordless

This feature is disabled by default for new tenants as of 8 June 2017. If you would like this feature enabled, please contact support to discuss your use case and prevent the possibility of introducing security vulnerabilities. Please see Client Grant Types for more information.

Lock Passwordless authenticates users by sending them an Email or SMS with a one-time password that the user must enter and confirm to be able to log in, similar to how WhatsApp authenticates you. This article will explain how to send a CODE using the Lock.Android library.

You can achieve a similar result by sending a LINK that the user can click to finish the passwordless authentication automatically, but a few more configuration steps are involved. You can check that article here.

In order to be able to authenticate the user, your application must have the Email/SMS connection enabled and configured in your Auth0 Dashboard.

Implementing CODE Passwordless

The first step is to add the PasswordlessLockActivity to your AndroidManifest.xml inside the application tag.


If your client has Social connections enabled you must add the corresponding Intent-Filter in the PasswordlessLockActivity to capture the call to the expected callback URL.

When the Passwordless connection is SMS you must also add the CountryCodeActivity to allow the user to change the Country Code prefix of the phone number.

  android:theme="@style/Lock.Theme.ActionBar" />

Next, add the Internet permission to your application:

<uses-permission android:name="android.permission.INTERNET" />


In any of your activities, you need to initialize PasswordlessLock and tell it to send a CODE. We'll indicate this by calling the useCode() method.

public class MainActivity extends Activity {

  private PasswordlessLock lock;

  protected void onCreate(Bundle savedInstanceState) {
    // Your own Activity code
    Auth0 auth0 = new Auth0("YOUR_CLIENT_ID", "YOUR_AUTH0_DOMAIN");
    lock = PasswordlessLock.newBuilder(auth0, callback)

  protected void onDestroy() {
    // Your own Activity code
    lock = null;

  private LockCallback callback = new AuthenticationCallback() {
     public void onAuthentication(Credentials credentials) {

     public void onCanceled() {
        //User pressed back

     public void onError(LockException error) {
        //Exception occurred

Finally, just start PasswordlessLock from inside your activity and perform the login.


Depending on which passwordless connections are enabled, Lock will send the CODE in an Email or SMS. The 'email' connection is selected first if available. Then the user must input the CODE in the confirmation step. If the value equals to the one the server is expecting, the authentication will be successful.