I read in the docs that you should be able to do export your tagged and starred content using the API.
Has someone already done it and knows how to do it?
I just want to do it as a backup in case something happens. I have many years of saved content now, so I think it would be good to do.
BazQux is awesome, and I feel like I never want to switch. I kind of don’t follow news that doesn’t support BazQux 
The easiest way would be to create a public feed (right-click on Tags or Starred items => Public feed => [enable]), and then open it in browser and add ?n=1000 to the URL to get more items.
For a JSON export of starred items you can use
https://bazqux.com/reader/api/0/stream/contents?output=json&n=1000&s=user/-/state/com.google/starred
if you have more than 1000 items, there will be a “continuation” field in the resulting JSON, you can add &c=<continuation token> to the URL to get the next chunk of starred items.
There’s no corresponding simple URL for all tags, you need to use s=user/-/label/TagName for every tag separately.