You can create a new field set with all the custom fields you need. For example i did this a bit ago: https://www.yoursite.com/api/items?fieldset=jsonfeed I created a new field set named jsonfeed and I added what i needed there. Go to website > website list > Field Sets and add a new one.

Hmmm. I've never done this, only read about it.

Go to your NS account and see which fieldsets you have available and then go to this url -> https://www.yoursite.com/api/items?fieldset=details for example.

I’m a little confused about this suggestion. So, Chris wants to use the items API to fetch data about a category record – the only fields you can select for your field set are item fields. So, how do you do this with the items API?

I missed a key parameter to be passed to the api. &commercecategoryid=categoryId