ChartFibonacciArc

 using cAlgo.API;
 namespace cAlgo
 {
     // This sample shows how to use Chart.DrawFibonacciArc method to draw a Fibonacci Arc
     [Indicator(IsOverlay = true, TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
     public class FibonacciArcSample : Indicator
     {
         protected override void Initialize()
         {
             Chart.DrawFibonacciArc("Arc", Chart.FirstVisibleBarIndex, Bars.ClosePrices[Chart.FirstVisibleBarIndex], Chart.LastVisibleBarIndex, Bars.ClosePrices[Chart.LastVisibleBarIndex], Color.Red);
         }
         public override void Calculate(int index)
         {
         }
     }
 }

 import clr
 clr.AddReference("cAlgo.API")
 from cAlgo.API import *
 class Test():
     def initialize(self):
         fibonacciArc = api.Chart.DrawFibonacciArc("Arc", api.Chart.FirstVisibleBarIndex, api.Bars.ClosePrices[api.Chart.FirstVisibleBarIndex], api.Chart.LastVisibleBarIndex, api.Bars.ClosePrices[api.Chart.LastVisibleBarIndex], Color.Red)
         fibonacciArc.IsInteractive = True