Problem statement
The Welcome Email template in Auth0 is sent when a user verifies their email address and has the ability to be disabled if needed. Is it possible to send custom data, such as language preference or custom URLs, that can be picked up in the Welcome Email with liquid syntax?
Solution
The built-in functionality of the Welcome Email does not support that use case.
NOTE: this could technically work if a client’s user pool is solely passwordless and database users. In that case, a Pre-User Registration Action could be leveraged at signup, adding the necessary data to a user’s metadata, which Liquid Syntax could then access in the Welcome Email template. However, for other 3rd Party SSO providers, this flow will not work.
A workaround would be to disable the Welcome Email in the dashboard and instead create a Post-Login Action to handle sending the Welcome Email. In this Action, it could also be possible to save the necessary user metadata to later access it in the Welcome Email template being sent. The following documentation shows how an email can be sent from a Rule.