This volume introduces the OpenAI Agent SDK as a foundation for constructing agent based applications that operate within modern software systems. The book focuses on how agents are structured, how they communicate with tools and services, and how workflows are composed in a scalable and maintainable manner.Readers are guided through the architectural concepts behind agent orchestration, task delegation, and state management, with attention given to practical design patterns rather than isolated code fragments. The book explores how agents interact with external APIs, databases, and services, and how these interactions can be organized into coherent, production ready workflows.Additional chapters address concerns that arise in real deployments, such as configuration strategies, error handling, logging, and system boundaries. Rather than presenting a single prescribed approach, the book emphasizes informed decision making and trade offs, enabling readers to adapt the SDK to their own engineering constraints and requirements.This book is intended for developers who want a structured, implementation focused understanding of how agent based systems can be built using the OpenAI Agent SDK within professional software environments.