You need to keep the state of the records of already processed, so you can filter those out. You can do that with a function node and the workflow static data.
I am really new to n8n as you will see. So here is my situation.
I query a rest api and get an array as answer. The next day i will do the same but want to compare the result to the day before to see if there are some new values.
The Rest-API is: https://awtrix.blueforcer.de/app?type=getAppList
So when there is a new entry in the array i will get an message. But how to compare to the result of yesterday?
Greeting from Germany #coronasucks
Btw. here the documentation about the static data: