jo is a command line utility for printing JSON objects

$ jo -p name=jo n=17 parser=false { "name": "jo", "n": 17, "parser": false }

or arrays

$ seq 1 10 | jo -a [1,2,3,4,5,6,7,8,9,10]

It has a manual: https://github.com/jpmens/jo/blob/master/jo.md