Plugins are authenticated for purposes of accessing and using application program interfaces (APIs) of a management service of a virtualized computing environment. In an authentication process, each plugin is associated with a session ticket that is unique to the plugin. The session ticket may be in the form of a single-use token that has a finite duration, and which may be used by the plugin to establish a session with the APIs of the management service. Because of the single-use and finite duration constraints of the token, the plugin is unable to use the token for other sessions and other plugins are also unable to use the same token to conduct their own sessions with the management service.