Am I missing something? The EmonTX is the Harvi.
It monitors the data every 10 seconds, then reports it to the EmonPi.
The EmonPi can publish* it to MQTT, subscribed by NodeRed, which can then ‘do stuff’.
In my case, turn on the hot water diversion, tell the car charger what to do (the smarts are in NodeRed), run pumps, charge the house battery, send alerts that there’s spare power, etc.
*If you set it up, obvs.