For the integration of ONLYOFFICE Document Builder into any application, the .Net doctrenderer library is used. The current application version contains five main classes:

  • CDoctrenderer class - used by ONLYOFFICE Document Builder in the file conversion process.
  • CDocBuilder class - used by ONLYOFFICE Document Builder for the document file (text document, spreadsheet, presentation, form document, PDF) to be generated.
  • CDocBuilderValue class - used by ONLYOFFICE Document Builder for getting the results of called JS commands. It represents a wrapper for a JS object.
  • CDocBuilderContextScope class - the stack-allocated class which sets the execution context for all operations executed within a local scope.
  • CDocBuilderContext class - used by ONLYOFFICE Document Builder for getting JS context for working.



using docbuilder_net;

using OfficeFileTypes = docbuilder_net.FileTypes;
using CValue = docbuilder_net.CDocBuilderValue;
using CContext = docbuilder_net.CDocBuilderContext;
using CContextScope = docbuilder_net.CDocBuilderContextScope;

namespace Test
    public class Program
        public static void Main(string[] args)
            string workDirectory = "C:/Program Files/ONLYOFFICE/DocumentBuilder";
            string resultPath = "result.docx";

            // add the Docbuilder dlls to the path
            System.Environment.SetEnvironmentVariable("PATH", System.Environment.GetEnvironmentVariable("PATH") + ";" + workDirectory);

            Test(workDirectory, resultPath);

            // uncomment these lines to check the finalizer calls
            // GC.Collect();
            // Console.ReadKey();
        public static void Test(string workDirectory, string resultPath)
            var doctype = (int)OfficeFileTypes.Document.DOCX;

            CDocBuilder oBuilder = new CDocBuilder();
            oBuilder.SetProperty("--work-directory", workDirectory);

            CContext oContext = oBuilder.GetContext();
            CContextScope oScope = oContext.CreateScope();
            CValue oGlobal = oContext.GetGlobal();

            CValue oApi = oGlobal["Api"];
            CValue oDocument = oApi.Call("GetDocument");
            CValue oParagraph = oApi.Call("CreateParagraph");
            CValue oContent = oContext.CreateArray(1);

            oParagraph.Call("SetSpacingAfter", 1000, false);
            oParagraph.Call("AddText", "Hello from .net!");
            oContent[0] = oParagraph;
            oDocument.Call("InsertContent", oContent);

            oBuilder.SaveFile(doctype, resultPath);



var oDocument = Api.GetDocument();
var oParagraph = Api.CreateParagraph();
oParagraph.SetSpacingAfter(1000, false);
oParagraph.AddText("Hello from .net!");
builder.SaveFile("docx", "result.docx");