is it possible to run node red on an Arduino Portenta H7?
Welcome to the forum.
No, you cannot run Node-RED on an Arduino Portenta H7.
Node-RED runs on top of the node.js runtime. That requires a full operating system - not an embedded runtime like you find on the arduino family of devices.
Ah I see, thanks for the quick reply!
You can, of course, run code on the Arduino that communicates with node-red running on, for example, a pi, using MQTT or other protocols.