### Programming with the Designer API

The class API is the root of the class hierarchy of JReport Designer API (Designer API and Catalog API). It is an abstract class and provides a series of editing methods for users. The Designer API class has an API as a super class.

Designer and MultiUserDesigner are the principal classes that manipulate reports. The application creates a Designer instance and calls Designer methods to create or modify a report. For details of summary of FIELD, CONSTRUCTOR and METHOD, see JReport Designer Javadoc jet.api package in `<install_root>\help\designer\api`, which includes all documents generated by Javadoc. In addition, JReport provides you with some sample files in `<install_root>\help\designer\samples`.

The following topics explain how to use the Designer API:

- Preparations
- Using the Designer API
- Illustrative examples