This optional key is used to specify launch on demand sockets that can be used to let launchd know when to run the job. The job must check-in to get a copy of the file descriptors using APIs outlined in launch(3). The keys of the top level Sockets dictionary can be anything. They are meant for the application developer to use to differentiate which descriptors correspond to which application level protocols (e.g. http vs. ftp vs. DNS...). At check-in time, the value of each Sockets dictionary key will be an array of descriptors. Daemon/Agent writers should consider all descriptors of a given key to be to be effectively equivalent, even though each file descriptor likely represents a different networking protocol which conforms to the criteria specified in the job configuration file.
The parameters below are used as inputs to call getaddrinfo(3).