Link Accounts using Authentication API (Deprecated)

This method of linking accounts using the linking endpoint of the Authentication API, either through Lock or by manually calling the API, is deprecated and should no longer be used. The POST /api/v2/users/{id}/identities should be used instead. For more information refer to the Migration Notice.

<script src=""></script>
<script type="text/javascript">
  var lock = new Auth0Lock('YOUR_CLIENT_ID', 'YOUR_AUTH0_DOMAIN', {
    callbackURL: 'https://YOUR_APP/callback',
    languageDictionary: {
      title: 'Link with another account'
    auth: { 
      params: {
        access_token: '...LOGGED_IN_USER_ACCESS_TOKEN...' 

  function signin () {{

<a href="javascript:signin()">Add account</a>

Notice the access_token fragment of the URL that is normally not present. Auth0 generates this access_token when a user logs in and uses it to uniquely identify the user.

Manual initiation

The following example will manually initiate the authentication transaction:

https://YOUR_AUTH0_DOMAIN/authorize?response_type=code&scope=openid &client_id=YOUR_CLIENT_ID &redirect_uri=https://YOUR_APP/callback &access_token=...LOGGED_IN_USER_ACCESS_TOKEN...

Obtain an authenticated user's access_token

The SDK for your platform should make the access_token available in simplest way for your platform. For example:

  • If you are using Lock in Popup Mode in a SPA, the access_token is available as a callback parameter:

    var lock = new Auth0Lock('YOUR_CLIENT_ID', 'YOUR_AUTH0_DOMAIN');, profile, id_token, access_token) {
      //save access_token here for linking other accounts
  • If you are using passport-auth0 in a regular Node.js web app, the access_token is available in the strategy callback and can be saved to the session for later use:

    var Auth0Strategy = require('passport-auth0'),
        passport = require('passport');
    var strategy = new Auth0Strategy({
       domain:       'YOUR_AUTH0_DOMAIN',
       clientID:     'YOUR_CLIENT_ID',
       clientSecret: 'YOUR_CLIENT_SECRET',
       callbackURL:  'https://YOUR_APP/callback',
       passReqToCallback: true //need this to save the accessToken to session
      function(req, accessToken, refreshToken, extraParams, profile, done) {
        // save accessToken to session to be able to link accounts later
        req.session.accessToken = accessToken;
        // profile has all the information from the user
        return done(null, profile);
  • If you are using ASP.NET, the access_token is available as a claim:

    <%= ClaimsPrincipal.Current.FindFirst("access_token").Value %>
  • If you are building your own implementation, the access_token will be available through the standard OAuth2 flow:

    1. User logs in and returns to the app with a code
    2. The app exchanges the code for the access_token

    The details of these exchanges are available at Identity Protocols supported by Auth0.

Unlinking Accounts

To unlink a specific account, POST request to the following url:


The body should be:

    access_token: "LOGGED_IN_USER_ACCESS_TOKEN", // Primary identity access_token
    user_id: "LINKED_USER_ID" // (provider|id)
Was this article helpful?