AI agents are the next frontier of practical artificial intelligence—autonomous systems that can plan, use tools, and act on your behalf. But how do they actually work, and how can you harness them today without getting lost in hype? 'Mastering AI Agents' is the plain-English guide you've been waiting for. From understanding the core loop of perception, reasoning, and action, to setting up your first helper agent, this book walks you through everything step by step. You'll learn the different types of agents—from copilots that assist to swarms that collaborate—and discover how to give them real-world tools like search engines, calculators, and APIs. Practical exercises show you how to prompt agents for dependable results, build multi-agent workflows for complex projects, and implement safety guardrails. Whether you're a professional looking to automate tedious tasks or a curious learner eager to experiment, this book equips you with the knowledge to start using AI agents effectively and responsibly. You'll walk away with a clear mental model, a toolkit of best practices, and the confidence to deploy agents in your own work. No PhD required—just a willingness to try. Part of The Practical AI Library.