         $.ajax options
 
     scale: (confirmedOrPromptData) =>
+        data =
+            instances: confirmedOrPromptData.instances
+        duration = @_parseDuration(confirmedOrPromptData.duration)
+        if duration
+            data[durationMillis] = duration
         $.ajax
           url: "#{ @url() }/scale?user=#{ app.getUsername() }"
           type: "PUT"
           contentType: 'application/json'
-          data: JSON.stringify
-              instances: confirmedOrPromptData.instances
-              durationMillis: @_parseDuration(confirmedOrPromptData.duration)
+          data: JSON.stringify data
 
     makeScalePermanent: (callback) =>
         $.ajax(

        ).then callback

    bounce: (incremental, duration) =>
        $.ajax
            type: "POST"
            url:  "#{ @url() }/bounce?user=#{ app.getUsername() }"
            contentType: 'application/json'
            data: JSON.stringify
              durationMillis: @_parseDuration(duration)
              incremental: incremental

    exitCooldown: =>
        $.ajax

            type: 'POST'

    pause: (killTasks, duration) =>
        data =
            user:      app.getUsername()
            killTasks: killTasks
        duration = @_parseDuration(duration)
        if duration
            data[durationMillis] = duration
        $.ajax
            url:         "#{ @url() }/pause"
            type:        'POST'
            contentType: 'application/json'
            data: JSON.stringify data

    run: (confirmedOrPromptData) ->
        options =
