man npm-init (1): Interactively create a package.json file

SYNOPSIS

npm init

This will ask you a bunch of questions, and then write a package.json for you.

It attempts to make reasonable guesses about what you want things to be set to, and then writes a package.json file with the options you've selected.

If you already have a package.json file, it'll read that first, and default to the options in there.

It is strictly additive, so it does not delete options from your package.json without a really good reason to do so.