test.cs

[HttpPost]
public JsonResult CreateForm(string document) {
  using (TXTextControl.ServerTextControl tx = new TXTextControl.ServerTextControl()) {
    tx.Create();

    tx.Load(Convert.FromBase64String(document),
      TXTextControl.BinaryStreamType.InternalUnicodeFormat);

    List<FormSection> formSections = new List<FormSection>();

    foreach (TXTextControl.SubTextPart section in tx.SubTextParts) {

      byte[] data;

      section.Save(out data, BinaryStreamType.InternalUnicodeFormat);

      var fields = GetFormFields(data);

      formSections.Add(new FormSection() {
        Name = section.Name,
        FormFields = fields
      });
    }

    return Json(formSections, JsonRequestBehavior.AllowGet);

  }

}