// URL format of the POST query to add data to DataService.
http(s)://[Bpm'online application address]/[Configuration number]/dataservice/[Data fromat]/reply/InsertQuery
// URL example for the POST query to add data to DataService.
http(s)://example.bpmonline.com/0/dataservice/json/reply/InsertQuery

{
    "RootSchemaName":"[Root object schema name]",
    "OperationType":[Record operation type],
    "ColumnValues":{
        "Items":{
            "Added column name":{
                "ExpressionType":[Expression type],
                "Parameter":{
                    "DataValueType":[Data type],
                    "Value":"[Column value]"
                }
            }...
        }
    }
}

using System;
using System.Text;
using System.IO;
using System.Net;
using System.Collections.Generic;
using Terrasoft.Nui.ServiceModel.DataContract;
using Terrasoft.Core.Entities;
using System.Web.Script.Serialization;

// Main bpm'online URL. Has to be changed to a custom one.
private const string baseUri = @"http://example.bpmonline.com";
// Query string to the Login method of the AuthService.svc service.
private const string authServiceUri = baseUri + @"/ServiceModel/AuthService.svc/Login";
// InsertQuery query path string.
private const string insertQueryUri = baseUri + @"/0/DataService/json/reply/InsertQuery";
// Bpm'online cookie authentication.
private static CookieContainer AuthCookie = new CookieContainer();

// Query class instance.
var insertQuery = new InsertQuery()
{
    // Root schema name.
    RootSchemaName = "Contact",
    // Added column values collection.
    ColumnValues = new ColumnValues()
};
// Expression class instance of the object schema query.
// Used to configure the [Full name] column.
var columnExpressionName = new ColumnExpression
{
    // Query object schema expression type — parameter. 
    ExpressionType = EntitySchemaQueryExpressionType.Parameter,
    // Query expression parameter.
    Parameter = new Parameter
    {
        // Parameter value.
        Value = "John Best",
        // Parameter data type — string.
        DataValueType = DataValueType.Text
    }
};

// Expression class instance of the object schema query.
// Used to configure the [Business phone] column.
var columnExpressionPhone = new ColumnExpression
{
    ExpressionType = EntitySchemaQueryExpressionType.Parameter,
    Parameter = new Parameter
    {
        Value = "+12 345 678 00 00",
        DataValueType = DataValueType.Text
    }
};
// Expression class instance of the object schema query.
// Used to configure the [Job title] column.
var columnExpressionJob = new ColumnExpression
{
    ExpressionType = EntitySchemaQueryExpressionType.Parameter,
    Parameter = new Parameter
    {
        // The "Developer" record GUID of the [Job title] system lookup.
        // Change to the record GUID in bpm'online.
        Value = "11D68189-CED6-DF11-9B2A-001D60E938C6",
        // Parameter data type — unique ID.
        DataValueType = DataValueType.Guid
    }
};
// Query column collection initialization.
insertQuery.ColumnValues.Items = new Dictionary<string, ColumnExpression>();
// Adding query expressions to the added column collection.
// The [Full name] column.
insertQuery.ColumnValues.Items.Add("Name", columnExpressionName);
// The [Business phone] column.
insertQuery.ColumnValues.Items.Add("Phone", columnExpressionPhone);
// The [Job title] column.
insertQuery.ColumnValues.Items.Add("Job", columnExpressionJob);
// Class instance serialization of the JSON string adding query. 
var json = new JavaScriptSerializer().Serialize(insertQuery);

// Converting JSON string object to a byte array.
byte[] jsonArray = Encoding.UTF8.GetBytes(json);
// Creating HTTP query instance.
var insertRequest = HttpWebRequest.Create(insertQueryUri) as HttpWebRequest;
// Defining method query.
insertRequest.Method = "POST";
// Defining query content type.
insertRequest.ContentType = "application/json";
// Adding the previously received authenticated cookie to the receiveing data query.
insertRequest.CookieContainer = AuthCookie;
// Define query content length.
insertRequest.ContentLength = jsonArray.Length;
// Adding a JSON object to the query.
using (var requestStream = insertRequest.GetRequestStream())
{
    requestStream.Write(jsonArray, 0, jsonArray.Length);
}
// Executing the HTTP query and receiving answer from server.
using (var response = (HttpWebResponse)insertRequest.GetResponse())
{
    // Displaying answer in console.
    using (StreamReader reader = new StreamReader(response.GetResponseStream()))
    {
        Console.WriteLine(reader.ReadToEnd());
    }
}

diff: /**SCHEMA_DIFF*/[
    // Metadata to be added to the custom button section.
    {
        // The element is added to the page.
        "operation": "insert",
        // Parent interface element name to which the button is added.
        "parentName": "ActionButtonsContainer",
        // The button is added to the interface element collection  
        // of the parent element (its metaname is specified in parentName).
        "propertyName": "items",
        // Added button metaname.
        "name": "InsertQueryContactButton",
        // Additional element properties.
        "values": {
            // Added element type — button.
            itemType: Terrasoft.ViewItemType.BUTTON,
            // Binding button caption to the localizable schema string.
            caption: { bindTo: "Resources.Strings.InsertQueryContactButtonCaption" },
            // Binding method of processing the button click.
            click: { bindTo: "onInsertQueryContactClick" },
            "layout": {
                "column": 1,
                "row": 6,
                "colSpan": 1
            }
        }
    }
]/**SCHEMA_DIFF*/

methods: {
    // Method of processing the button click.
    onInsertQueryContactClick: function() {
        // Creating the Terrasoft.InsertQuery class instance.
        var insert = Ext.create("Terrasoft.InsertQuery", {
            // Root schema name.
            rootSchemaName: "Contact"
        });
        // Setting the Terrasoft.ParameterExpression value-parameters.
        // A value-parameter instance is created and added to the column value collection.
        // Creating a value-parameter instance for the [Job title] column.
        insert.setParameterValue("Name", "John Best", Terrasoft.DataValueType.TEXT);
        // Creating a value-parameter instance for the [Business phone] column.
        insert.setParameterValue("Phone", "+12 345 678 00 00", Terrasoft.DataValueType.TEXT);
        // Creating a value-parameter instance for the [Job title] column.
        insert.setParameterValue("Job", "11D68189-CED6-DF11-9B2A-001D60E938C6", Terrasoft.DataValueType.GUID);
        // Data update query.
        insert.execute(function(response) {
            // Displaying server answer 
            window.console.log(response);
        });
        // Updating list data.
        this.reloadGridData();
    }
}