User server
A user server is a dedicated server for your users. It exposes an action invocation endpoint for user server actions. These actions include:
create_user
get_user
get_user_by_email_address
update_user_email_address
update_user_password_hash
increment_user_sessions_counter
delete_user
Because user server actions provide direct access to your user database, the action invocation endpoint should be protected and only accessible to trusted clients. Some options are private networks and request signing.
Guides for implementing the server is available: