Auth0 is the leading platform for authentication and authorization for web2 applications and services in retail, publishing, B2B SaaS, and more. Sign-In with Ethereum was recently integrated into Auth0 by Spruce in collaboration with Auth0 and the Auth0 Lab team.
The entire workflow involved can be seen in this activity diagram:
An example application to show off the authentication flow can be found here. The example features a mock NFT gallery website where users can Sign-In with Ethereum, and their NFT holdings are resolved via the OpenSea API once authenticated.
After hitting the login button, users are redirected to the Auth0 flow and Sign-In with Ethereum using the provided interface. Once authenticated, users are then redirected back to the application where they can view their gallery.
As part of the login, the application also resolves the user's ENS name if present. Users can then return to the main splash screen or disconnect from the application.