An AppleScript that waits for a message to appear in the Mac "Notes" application, then perform an action. An iOS user can use Siri to "Write a note", and then say "What apps are running?" to get a list of all apps running on the Mac, "Shut down" to shut down the Mac, "Go to sleep" to put the Mac to sleep, or "Restart my mac" to restart the Mac. …

Siri Listener

on run
  -- just here to get things started...
end run

on idle
	tell application "Notes"
		if exists note "What apps are running?" then
			delete note "What apps are running?"
			tell application "Finder"
				set myRunningApps to name of every process whose visible is true
				tell application "Notes"
					if exists note "Running Apps:" then
						delete note "Running Apps:"
					end if
					set noteTitle to "Running Apps:"
					set AppleScript's text item delimiters to ", "
					set appsList to myRunningApps as text
					make new note at folder "Notes" with properties {name:noteTitle, body:appsList}
				end tell
			end tell
		else if exists note "Shut down" then
			delete note "Shut down"
			tell application "Finder" to quit
		else if exists note "Go to sleep" then
			delete note "Go to sleep"
			tell application "Finder" to sleep
		else if exists note "Restart my mac" then
			delete note "Restart my mac"
			tell application "Finder" to restart
		end if
	end tell
	return 1
end idle