Thanks for taking interest in GroupDocs APIs.
GroupDocs.Viewer is a back-end API that enables you to render the source document into either HTML pages or images. You can then view these HTML pages or images in your front end document viewer application. It does not provide any built in functionality to create annotations on the document pages when displayed in the front end viewer. You can achieve this functionality by following below steps:
- Render document using GroupDocs.Viewer and display rendered pages in the front end viewer.
- Use jQuery to create annotations in the front end viewer.
- Add annotations on the document and save it using GroupDocs.Annotation on the back-end.
We have also created some showcase applications that may help you to understand the workflow of the APIs. We will require you to mention your platform (.NET or Java) so that we can provide you some specific details. We shall be looking forward to your response.