jq is an easy way to manipulate json, for example an API response:
curl "https://something.com/api" -d '{...}' | jq '.'
If you have an array of objects:
[{
"id": 1,
...
}, {
"id": 2,
...
}]
and want to extract a single field, you can use map:
curl ... | jq 'map(.[] | .id)'
[
1,
2
]