jf is a trivial JSON formatter. It's basically a wrapper around the marvelous "JSON for Modern C++" by Niels Lohmann. Output is written to stdout.
$ jf -h
jf [-h] [-i n] [file]
-h Shows this help message.
-i Number of spaces to indent. Default is 2. Use -1 for no indentation at all.
file Path to file to indent. When no path is provided the data is read from stdin.The jf utility exits 0 on success, and >0 if an error occurs. On success the output written to stdout. JSON parse errors are written to stderr.