Custom scripts

Hi guys, I would like to create a custom script for service/host monitoring and then, create a graph and alerts from it.
Im used to create custom graphs using cacti and custom alerts using nagios.
Now , I need to replicate this on librenms.
Is it possible ?
Is there a “hello world” tutorial for this ? perhaps adding a simple ping service that:
Graph packet loss and trigger the alarm if package loss % is greater than 15%.