I run a heavy data-driven content portal so I built a bot (golang) to help with data aggregation and automated export to Hugo. It also offers a customizable API that can be helpfull with getJSON calls.
Yes, it actually generates the data directly on the hugo data dir.
Yes It’s also possible as you can register your own API endpoints which can communicate the data back to Hugo when you want to pull the data straight from templates.
As an example, on bitcointechweekly.com I generate a unique Bitcoin donation address for every new article posted by our authors by using getJSON on a custom API endpoint. Since hugobot is connected to an sqlite db, you can fill any data you wish and either export it or expose it through the API. So to be clear this feature is not really related to the automated content fetching.
Sorry I didn’t have time to thoroughly document the project yet, will do it as soon as I have some time.