rpc_port

raw details (from release v2.2.3):

{
  "name": "rpc_port",
  "properties": {
    "long": "rpc-port",
    "value_name": "PORT",
    "takes_value": "true",
    "validator": "port_validator",
    "help": "Enable JSON RPC on this port, and the next port for the RPC websocket"
  },
  "isDeprecated": false
}