We need a data.json file that lists all of the the datasets on the site with their resource in a json format.
To do this use json views. See: /admin/structure/views/view/dkan_dataset_json/edit as an example.
The file needs to follow this specification: http://project-open-data.github.io/schema/
There is a validator (http://project-open-data.github.io/json-validator/) though keep in mind it is buggy: https://github.com/project-open-data/json-validator/issues/7