# Before You Start

This document describes application programming interfaces (APIs), syntax, parameters, and examples of Document Database Service (DDS). You can search for information you need according to Table 1.

Table 1 Documentation guide
Section | Description
--- | ---
API Overview | DDS API components and API list
Environment Preparations | Preparations before using the APIs, including obtaining the request authentication and project ID
API Calling | Representational State Transfer (REST) message bodies, calling methods, and examples
API Description | DDS APIs, including APIs used for querying information about API version, database version, and DB instance specifications, and managing DB instances.
Appendix | Understand the status codes and error codes about DDS APIs.