you could add in a check column once you have sent it the first time then add a filter node before you send to api that filters out all those with the check column. i.e Step 1 - add filter before send to api to filter out if "sent" = Y Step 2 - send data to api Step 3 - once sent add Y to "sent" column in gsheets Step 4 - if data is sent to api, the filter should filter out already sent data. All the above depends on how you have your workflow setup though but thats the general gist