Cannot deserialize the current JSON array (e.g. [1,2,3])

I think the problem you’re having is that your JSON is a list of objects when it comes in and it doesnt directly relate to your root class.

var content would look something like this (i assume):

[
  {
    "id": 3636,
    "is_default": true,
    "name": "Unit",
    "quantity": 1,
    "stock": "100000.00",
    "unit_cost": "0"
  },
  {
    "id": 4592,
    "is_default": false,
    "name": "Bundle",
    "quantity": 5,
    "stock": "100000.00",
    "unit_cost": "0"
  }
]

Note: make use of http://jsonviewer.stack.hu/ to format your JSON.

So if you try the following it should work:

  public static List<RootObject> GetItems(string user, string key, Int32 tid, Int32 pid)
    {
        // Customize URL according to geo location parameters
        var url = string.Format(uniqueItemUrl, user, key, tid, pid);

        // Syncronious Consumption
        var syncClient = new WebClient();

        var content = syncClient.DownloadString(url);

        return JsonConvert.DeserializeObject<List<RootObject>>(content);

    }

You will need to then iterate if you don’t wish to return a list of RootObject.

I went ahead and tested this in a Console app, worked fine.