This is a text file either as flat list or json and in the config of the external feed you define either the delimiter of the flat list or jq query to parse the json structure.
https://sc1.checkpoint.com/documents/R82/WebAdminGuides/EN/CP_R82_SecurityManagement_AdminGuide/Cont...
Use Case: If you use zscaler you can directly download a json with objects from them
https://config.zscaler.com/api/zscaler.net/cenr/json
then you tell your network feed how to parse it. Here for this use case the jq query:
."zscaler.net"[] | .[] | .[] | .range
That's it.
The feature then retrieves the json and converts it to a simple list, same as if you chose flat list as format.
Just simulated it on the cli to demonstrate:
curl -s https://config.zscaler.com/api/zscaler.net/cenr/json | jq '."zscaler.net"[] | .[] | .[] | .range' | head -n 5
"2a03:eec0:3900::/40"
"159.254.250.0/23"
"159.254.242.0/23"
"159.254.244.0/23"
"159.254.246.0/23"
Flat list is easy. Just a list with one object per line.
So would look somewhat like this if you choose IP as type
# Blocked IP addresses - updated daily
# Last update: 2025-03-13
1.2.3.4
10.0.0.0/24
192.168.1.1-192.168.1.50
malicious-domain.com
*.bad-example.org
203.0.113.5
198.51.100.0/24
and now to something completely different - CCVS, CCAS, CCTE, CCCS, CCSM elite