ClouDNS Reseller Panel provides API for Single Sign-On (SSO) integration.
Resellers can log their clients within the control panel direct by building of URL with the username and password of their sub-user account. This option is available for easy and fast integration, but it may expose the api user credentials within the user's browser history.
Alternative and secure option is to use SSO integration by creating of a session of the user over the API by using his credentials and then to log the user within the preconfigured session.
More details for the API can be seen on the sub-pages.