The CPQ API reference Guide is divided into two sections: API Reference and Scenarios.

API ReferenceThe API reference section details the APIs that you can use to manipulate Conga objects through API calls and passing parameters. The API reference section also includes some code samples.
ScenariosThe Scenarios section details examples of the APIs you require to complete a specific task such as, adding products and constraint rules to the cart. The scenarios are classified by theme. You can refer to the generic examples of scenarios to identify the calls you can use to achieve your objective.