If you want to get the Item data in the form of JSON Object using API then you need to work with the
ItemService using Sitecore.
You can use the
ItemService in the following ways:
For example, if you want to get the item details then you can call it using this API request.
There are lots of examples provided in the Item Service and you can use whatever is required of you.
Here are the details for this.
And this will also help to get the details of parameters you can use in the call.
Finally, if the above APIs are not able to give you the specific data that you need, then I would suggest you write the C# code. Like if you want to get the renderings on an item then you can write something like this.
string deviceName = "Default".ToLower();
var deviceItem = item.Database.Resources.Devices.GetAll().Where(d => d.Name.ToLower() == deviceName).First();
if (deviceItem != null)
var renderings = item.Visualization.GetRenderings(deviceItem, false);
if (renderings != null)
foreach (var renderingref in renderings)
// Get your data from renderingref, bind it in a class and convert that in JSON.
And you can get the data you need and create your own JSON object.