origami:

json(object)

Render the contents of the object in JSON format.

The ori tool uses YAML as its default output format, so you can use the json function to reformat the output as JSON:

$ ori greetings.yaml
Alice: Hello, Alice.
Bob: Hello, Bob.
Carol: Hello, Carol.
$ ori json greetings.yaml
{
  "Alice": "Hello, Alice.",
  "Bob": "Hello, Bob.",
  "Carol": "Hello, Carol."
}