We have successfully implemented and fully customized these passwordless screens using ACUL:
Email entry using login-id, signup-id
Email OTP verification using login-passwordless-email-code
What we have not achieved is the second signup step after OTP verification. For new users, we need to collect first name, last name, phone number, date of birth, and two consent checkboxes before completing signup.
Auth0 Forms can collect this information through a Post-Login Action, but we have not found a way to fully customize that form pixel by pixel with the same React/CSS control ACUL provides.
Is there an ACUL screen for this profile-completion step? If not, can Auth0 Forms use a completely custom React UI?
I understand that you are looking for a more customizable way to collect user information during the signup process with ACUL, apart from using Auth0 Forms.
At this moment there is no ACUL screen for profile completion and Auth0 Forms cannot accept a completely custom React UI, however allow me to share a breakdown of why and the recommended Auth0 workaround for your exact use case.
1. ACUL Limitations for Profile Completion
ACUL (Advanced Customizations for Universal Login) is strictly designed to replace standard identity boundaries (Login, standard Signup, Reset Password, and standard MFA). It does not support custom business workflows, multi-step onboarding, or arbitrary progressive profiling screens. You cannot host a custom data-collection form directly within Universal Login using ACUL.
2. Auth0 Forms UI Limitations
Auth0 Forms is built specifically as a no-code visual editor. While it natively handles the backend logic for progressive profiling and allows some styling customization, you cannot drop a custom React application into Auth0 Forms to achieve the pixel-by-pixel control you have with your ACUL screens. It relies on its own pre-built UI components.
The Recommended Solution: Post-Login Redirect Action
If you absolutely require pixel-perfect React/CSS control for this second signup step to seamlessly match your ACUL experience, Auth0’s official recommendation is to use a Post-Login Action with a Redirect.
If you choose this route, the flow works like this:
Authenticate: The user completes the OTP verification using your ACUL login-passwordless-email-code screen;
Evaluate: A Post-Login Action evaluates the user’s profile. If they are missing the required fields (name, DOB, phone, consents), the Action pauses the authentication flow and redirects the user to an external, self-hosted React application;
Collect & Update: Your custom React app renders the profile-completion form. Once submitted, your app uses the Auth0 Management API to update the user’s metadata/profile;
Resume: Your app redirects the user back to the Auth0 /continue endpoint to finalize the authentication flow and issue the tokens.
Notes:
Auth0 Forms does not currently support rendering arbitrary React components or providing the same level of React/CSS control that ACUL offers. If your branding requirements demand pixel-perfect React component control equivalent to ACUL, you would need to implement a custom post-login redirect to your own application page (outside Universal Login) where you can render a fully custom React form, then pass the collected data back to Auth0 via the Management API or a custom backend.