Automatic login after creating Auth0 user

Has anyone figured out how to automatically log user in after creating them using the Auth0 Management API?

During the onboarding process of our product, I create an user using Auth0 Management API (https://auth0.com/docs/api/management/v2#!/Users/post_users) and then I would like to automatically log them in so they could start using our product without the friction of doing the login process again. But how to do this?

After the user creation, I’d somehow need to generate a jwt access token for that user but I can’t seem to find the right Auth0 API calls to do this. Could someone point me to the right direction?

It seems this has been asked already in the past in these posts:


So hopefully this isn’t utterly impossible.

Hello @MarkusK,

I’m not sure this is quite what you are looking for, but maybe you can use passwordless authentication, sending the user a magic link: https://auth0.com/docs/connections/passwordless/regular-web-app-email-link

Sorry for being inexact here @markd :slight_smile: I’ll try to elaborate a bit.

We have two uses cases:

  1. A new user comes to the site and signs up. During the sign up, we create a user profile in our system and Auth0. When user completes the sign up (=== onboarding), we want automatically log the user in. So they could start using the site straight away without doing anything else.

  2. existing user who wants login. This is a really simple case and we’re actually using Passwordless for this :slight_smile:

The use case 1) is the one I haven’t been able to figure out. During the sign up, we create the Auth0 user via Auth0 Management API (https://auth0.com/docs/api/management/v2#!/Users/post_users) but the end-point doesn’t seem to have any options for getting an access token for the freshly created user. So I’m looking for help with this: how do I automatically log that freshly created user in using Auth0 API (so that I’d get JWT access token to be used with our authenticated API)?

Hi @MarkusK,

No worries, and thanks for the clarification! I’m assuming you are using your own login / signup page? I know Universal Login will automatically log a user in after registration unless explicitly disabled. There does seem to be a ‘signup and login’ option in Auth0.js as well, though I’m not super familiar with it:

https://auth0.github.io/auth0.js/global.html#signupAndLogin

If you are calling the Mgmt API yourself, perhaps the code behind the various ‘signup + login’ options in Auth0.js may be instructive.

@MarkusK Did you accomplish what you wanted? If so, what worked?

I am also looking for a solution for a similar usecase.

In my case I am doing a custom signup in the app through /dbconnections/signup endpoint and I find no way of logging in the user after successfully signing up.

Is there a way to do so or am I forced to redirect the user to the login flow?

Cheers

Since you sign up the user via API, you have the password at that point, right (which you don’t need to persist anywhere, just keep it until the callback of the signup)? Can’t you then just use the
https://auth0.com/docs/api/authentication#get-token > Resource Owner Password grant?

1 Like

Thanks for the fast reply @mathiasconradt!

I was doing a login & signup process from the client-side but it may make more sense to use the backend as proxy with Auth0.

Cheers

I was able to get an access_token and id_token using what you mentioned, but I can’t figure out how to trigger the auto-login using those parameters? Would I send them to the /authorize URL somehow?

@jordan2 I am solving absolute same problem right now and I am gonna test what @mathiasconradt just said.

I have user’s password in the moment of signup so I am gonna get a token for him and 302 to myapp/authorize?code

Not sure what you understand under “auto-login” or “login” in general. If you have an access token (and ID token), then that’s an authenticated user at that point, nothing more to do. No more login action to do at that point.

No need for that. You have the token, that’s all. Not clear what else you’d need or why.

Let me clear that: I am working with Single Page Application as described in your tutorial.

The point is what to do with the token. I have to tell the auth0-spa-js - “Hey, we omitted standard process of sign-in, this is the token you should use for now”

Something like this.auth.useThisToke(token)

I can store this token in memory, modify your Interceptor and inject token into http header from memory. This will work. But AuthGuard will not recognize this token:

return this.auth.isAuthenticated$.pipe(
      tap(loggedIn => {
        if (!loggedIn) {
          this.auth.login(state.url);
        }
      })
    );

Auth0 for SPA works pretty well out of the box and I do not want to rewrite it just for a single purpose of “auto-login” after signup.

Thanks

Any updates on this? I’m in the same situation as luke1988 where I can generate the access_token for our user after creating their account, but I’m unsure how to provide the access_token/refresh_token to the Auth0 React library

Would like to know the same

We want to use an implicit signup to automatically create an account and login the user if they used an email address for the first time. Then if they try to signup with an email that was already used, they’ll have to use the passwordless flow to validate their email using a code.

@mathiasconradt how would you do this when you created a user for the passwordless connection, since there are no passwords involved here? I need to create a passwordless user using the management API at first and then allow them to login on another device using the passwordless code widget.

Hi Tom,

for this requirement, I think you can use the Authentication API to generate a OTP then for a particular user.

We want to use an implicit signup to automatically create an account and login the user if they used an email address for the first time.

Can you explain the use case and flow for this a bit more? What triggers the implicit signup in the first place. Is it you/your backend or the user himself doing something on the website? When you say “if they used an email address for the first time” -> would that be a login or signup attempt by the user? Using the Auth0 Login widget (Lock.js) or something custom from your side?

@mathiasconradt Unfortunately, using the Passwordless Authentication API doesn’t make sense, as it would send the OTP code to the user’s email rather than return it to our backend API creating the user. The entire idea here is that the we create an account and login the user automatically without the user having to do anything.

The implicit signup is implicit and not explicit, i.e. the user is not explicitly signing up. It is triggered by them using our platform, in this case writing a comment and leaving their email address in an input field. When this happens, and the email address has never been used before, our backend will create an account for them and log them in in the background, without them having to do anything.

An Auth0 widget or anything would not help here because they require explicit user interaction. We’d only show the passwordless login widget if our API then returns that the email is NOT unique and therefore the user would have to go through the Passwordless OTP flow.

Understood.

When this happens, and the email address has never been used before, our backend will create an account for them and log them in in the background

How do you protect against spam? Anybody can just use any email address, the email address isn’t verified at this point, if I see it correctly. Also, unless there’s bot protection in place, somebody could create a few thousand comments/accounts this way.

We want to use an implicit signup to automatically create an account and login the user if they used an email address for the first time. Then if they try to signup with an email that was already used, they’ll have to use the passwordless flow to validate their email using a code.

This way a malicious user can lock out other users by using their email address to create comments, isn’t it? Or at least could post one ‘weird’ comment that wasn’t actually posted by the actual email account owner.
(Asking because we’ve seen this as a problem a lot in the past. Legitimate users not being able to register because their email address is already in use - though never verified).

The entire idea here is that the we create an account and login the user automatically without the user having to do anything.

Ok, then (why) wouldn’t the approach I mentioned above work? (You can use it in combination with a Passwordless Account & Account Linking)

@mathiasconradt While I appreciate the feedback, I’m not here to debate our company’s UX and product decisions on these forums. I’m just trying to figure out how to do this (not why). You did not debate this for the database connection above, so why do so for a passwordless connection?

Details (outside scope of this discussion)

We won’t have issues with malicious users locking out others, because as mentioned before, when the same email address is used again, a user can prove their identity by going through the passwordless OTP flow in this case. All other devices will then be logged out.

We won’t have issues with SPAM because we’re not triggering any emails and all our comments are sandboxed within an individual conversation, which is only known to a few people behind a secret URL, and this is way outside the scope of this discussion.

The approach you mentioned will not work because the Management API V2 does not allow setting a password for users with the “email” (passwordless) connection. It’ll return a bad request HTTP error of "password" is not allowed whenever you try to do so.