public void inviteContact(ContactItem contact, String invitationMessage, String type) { try { ContactApi contactApi = new ContactApi(session.GetApiClient()); List <String> contactKeys = new List <String>(); contactKeys.Add(contact.Key); InviteUsersInput input = new InviteUsersInput(type, null, invitationMessage, contactKeys); InviteUsersResult result = contactApi.InviteUsers(input); if (result.Hdr.Rc != 0) { throw new Exception("Error while inviting contact key " + contact.Key); } } catch (Exception ex) { throw new Exception("Error while inviting contactkey " + contact.Key, ex); } }