The ServeCommand class is accessible via the paste.script.serve module.
" This command serves a web application that uses a paste.deploy\n configuration file for the server and application. \n \n If start/stop/restart is given, then --daemon is implied, and it will\n start (normal operation), stop (--stop-daemon), or do both.\n\n You can also include variable assignments like 'http_port=8080'\n and then use %(http_port)s in your config files.\n "
See the source for more information.