Have you seen gron[0]? It's similar: flattens JSON documents to make them easily greppable. But it also can revert (ie, ungron) so you can pipe json to gron, grep -v to remove some data, then ungron to get it back to json.

[0] https://github.com/tomnomnom/gron

Actively developed and written in Go.

The project linked to is from 2014 with last update in 2015.and it is on NPM...

What is left to say? Thank you!

I much prefer jq[1]. Actively developed and written in C.

[1]:https://github.com/stedolan/jq