I'm a python developer but new to the platform.  I have a project for a client and I need some high level guidance on how to approach it. 

I need to detect when a 5-minute moving average crosses a 20-minute moving average.  My thinking is I'll use MovingAverageType, and then watch for a cross in their values, then fire a Notification webhook to my client's endpoint.  

Is this the best approach?  Is there a "cross" indicator built-in?

Are there things to watch out for?