<script langauge="javascript" src="jquery-1.7.1.min.js"></script>
<script language="javascript" src="crypto.js"></script>
<script type='text/javascript' version='1.3'>

var Server = https://assessmentcenter.net/ac_api;
var FormOID = "D2FA612D-C290-4B88-957D-1C27F48EE58C";   // Sample form -- replace with your FormOID

function listCalibrations() {
    // Returns the following calibration format as json
    $.ajax({
    	url: Server + "/2014-01/Calibrations/" + FormOID + ".json",    // Sample calibration
        cache: false,
        type: "POST",
        data: "",
        dataType: "json",

        beforeSend: function(xhr) {
            var bytes = Crypto.charenc.Binary.stringToBytes(document.getElementById("txtRegistration").value + ":" + document.getElementById("txtToken").value);
            var base64 = Crypto.util.bytesToBase64(bytes);
            xhr.setRequestHeader("Authorization", "Basic " + base64);
        },
	
        success: function(data) { 
            var screen ="ItemID : A_GRM<br />";
            for (var j=0; j < data.Items.length; j++) {
                screen = screen + data.Items[j].ID + " : " + data.Items[j].A_GRM + "<br />"
            }
            document.getElementById("Content").innerHTML = screen;
        },
	
        error: function(jqXHR, textStatus, errorThrown) {
            document.write(jqXHR.responseText + ':' + textStatus + ':' + errorThrown);
        }
    })
}
                                

Based on twillio example to call RESTful services. (http://www.twilio.com/docs/api/rest)

using System;
using System.Collections;
using System.Configuration;
using System.IO;
using System.Net;
using System.Web;
using System.Text;
using System.Text.RegularExpressions;

public class TestHarness
{
    static void Main(string[] args)
    {
        string REGISTRATIONID ="31839849-ECE0-4F5E-BEAE-3D655ED65E31";  // Sample registration -- replace with your RegistrationOID
        string TOKEN ="F3738486-5A7D-41EF-8044-DCBAF800E2D4";           // Sample token -- replace with your TokenOID
        string API_URL = "https://assessmentcenter.net/ac_api/2014-01/Calibrations/.xml";

        string authstring = Convert.ToBase64String(Encoding.ASCII.GetBytes(String.Format("{0}:{1}", REGISTRATIONID, TOKEN)));
        ServicePointManager.Expect100Continue = false;     
        Byte[] postbytes = Encoding.ASCII.GetBytes(string.Empty);
        WebClient client = new WebClient();
        client.Headers.Add("Authorization", String.Format("Basic {0}", authstring)); 
        client.Headers.Add("Content-Type", "application/x-www-form-urlencoded");    
        byte[] resp = client.UploadData(API_URL, "post", postbytes);
        Console.WriteLine(Encoding.ASCII.GetString(resp));
    }
}
                                

Request:https://assessmentcenter.net/ac_api/2014-01/Calibrations/.json

Response:

{
    "Calibration": [
        {
            "OID": "C4ADCFAB-6B75-498E-9E94-AFD3BA211DC4",
            "Name": "PROMIS Bank v1.0 - Pain Behavior"
        },
        {
            "OID": "3156A7E4-CC27-4504-962A-B8472CAF1A59",
            "Name": "PROMIS Bank v1.0  Psychosocial Illness Impact Neg"
        },
        {
            "OID": "9DA933EC-4E3B-4409-8785-9D692010B7A2",
            "Name":"PROMIS Ped Bank v1.0 - Peer Rel"
        },
        {
            "OID": "5FAF7608-6175-4B89-A410-1E88D157E903",
            "Name": "PROMIS Bank v1.0  Applied Cog Abilities"
        },
        {
            "OID": "C0E737C9-EF7C-4842-8661-4B00F82C0FED",
            "Name":"PROMIS Ped Bank v1.0 - Fatigue"
        }
    ]
}
                                

// Requesting one calibration to be returned as an "Items" array
Request:https://assessmentcenter.net/ac_api/2014-01/Calibrations/C0E737C9-EF7C-4842-8661-4B00F82C0FED.json

Response:
                                

{
    "FormOID": "C0E737C9-EF7C-4842-8661-4B00F82C0FED",
    "Form": "PROMIS pediatric item bank for fatigue.",
    "Properties": [
        { "MinNumItems": "5" },
        { "MaxNumItems": "12" },
        { "IRTModel": "0" },
        { "SelectionMethod": "1" },
        { "MinTheta": "-4.00" },
        { "MaxTheta": "4.00" },
        { "ThetaIncrement": "0.1000" },
        { "MaxStdErr": "0.40" },
        { "SelectionGroupSize": "1" },
        { "LogisticScaling": "1.0000" },
        { "DistMean": "0.00" },
        { "DistStdDev": "1.00" },
        { "FirstItem": "" }
    ],
    "Items": [
        {
            "FormItemOID": "0498B286-AB56-405A-B5D8-E4EE2D8D928E",
            "ID": "3548R1",
            "A_GRM": "1.56457",
            "Map": [
                {
                    "ItemResponseOID": "2C57C1F7-EF7F-4E4B-8021-722A614AC8B3",
                    "StepOrder": "0",
                    "Threshold": "0.5439"
                },
                {
                    "ItemResponseOID": "EBD7076A-A3BC-45FB-AE1E-35978AA87017",
                    "StepOrder": "1",
                    "Threshold": "1.3687"
                },
                {
                    "ItemResponseOID": "D6F45EB7-C4A3-41D9-B575-1374F32A21F0",
                    "StepOrder": "2",
                    "Threshold": "2.2485"
                },
                {
                    "ItemResponseOID": "2D20F0D5-122C-4D95-B3D8-D38245B82A42",
                    "StepOrder": "3",
                    "Threshold": "2.8131"
                }
            ]
        },
        ...
        {
            "FormItemOID"...
        }
	] // Items array
}
                                

// Requesting all forms available to be returned as "Form" nodes Request: https://assessmentcenter.net/ac_api/2014-01/Calibrations/.xml

Response:

<?xml version="1.0" encoding="utf-8"?>
<calibrations>
    <calibration OID="C4ADCFAB-6B75-498E-9E94-AFD3BA211DC4" name="PROMIS Bank v1.0 - Pain Behavior" />
    <calibration OID="3156A7E4-CC27-4504-962A-B8472CAF1A59" name="PROMIS Bank v1.0 Psychosocial Illness Impact Neg" />
    <calibration OID="9DA933EC-4E3B-4409-8785-9D692010B7A2" name="PROMIS Ped Bank v1.0 - Peer Rel" />
    <calibration OID="5FAF7608-6175-4B89-A410-1E88D157E903" name="PROMIS Bank v1.0 Applied Cog Abilities" />
    <calibration OID="C0E737C9-EF7C-4842-8661-4B00F82C0FED" name="PROMIS Ped Bank v1.0 - Fatigue" />
    <calibration OID="8C3AA645-DC1D-4762-BCD2-E2F8DAC0B0EB" name="PROMIS Parent Proxy Bank v1.0 ?Upper Extremity" />
    <calibration OID="3F2FCBBA-E8A1-4D0B-A9AE-9AEABF5BF60B" name="PROMIS Ped Bank v1.0 - Upper Extremity" />
</calibrations>