API Basics in PHP

Introduction

The book «API Foundations in PHP» (author — John Folds, 2017, 238 pages) is a practical guide to creating modern web APIs in PHP. In the era of microservices and mobile applications, the ability to competently design and implement APIs is becoming one of the key skills of a backend developer. This book is not overloaded with theory — it focuses on specific examples and step-by-step construction of a full-fledged RESTful API.

What the book is about

The author consistently guides the reader through all stages of API development: from environment setup to deployment on a production server. The main focus is on:

• REST principles and proper endpoint design;
• Organizing routing without using frameworks — in pure PHP;
• Working with HTTP methods (GET, POST, PUT, DELETE);
• Authentication and authorization (tokens, JWT, OAuth 2.0);
• Error handling and data validation;
• API testing using Postman and PHPUnit;
• API documentation (Swagger/OpenAPI).

Each chapter contains ready-to-use code that can be immediately applied in a project. At the end of the book, the reader gets a fully working API for task management (TODO application) with a MySQL database.

Who this book is for

The book is intended for beginner and intermediate PHP developers who are already familiar with the basics of the language (variables, functions, classes, PDO) and want to learn how to create APIs. It will also be useful for those transitioning from a procedural approach to OOP and wanting to understand how modern backend services are built. Beginners in web development are recommended to first study basic PHP and SQL.

What the reader will learn

• How to design a database structure for an API;
• How to implement RESTful routing without frameworks;
• How to handle JSON requests and form correct HTTP responses;
• How to implement token-based authentication (JWT);
• How to protect an API from common vulnerabilities (SQL injection, XSS, CSRF);
• How to write unit tests for an API;
• How to document an API for other developers.

Strengths of the book

Practical focus. Unlike many academic publications, Folds offers ready-made solutions that can be adapted to your own tasks. The code is written neatly, with comments and adherence to PSR standards.

No framework dependency. The author uses only native PHP, which allows for a deeper understanding of how APIs work. After reading the book, it is easy to move on to Laravel, Symfony, or Slim.

Step-by-step structure. Each chapter logically continues the previous one, and a complete project is given at the end. This helps reinforce the material.

Relevance. Despite being from 2017, the described principles (REST, JWT, PDO) remain industry standards in 2025.

Who it is recommended for

The book will be useful for:

• PHP developers wanting to learn API creation;
• Students and novice programmers studying backend;
• Developers transitioning from other languages (Python, Java) to PHP;
• Anyone who wants to understand how modern web services work from the inside.

If you are looking for a compact but informative guide to APIs in PHP — this book will be an excellent choice. It will not replace official documentation, but it will provide a solid foundation for independent development.