Armed with this knowledge, you will approach any third-party authentication tool or custom layer with more confidence, understanding precisely what is happening under the hood.

We encourage you to adapt this code for your own projects. There is no better way to solidify your knowledge than by implementing these concepts in your own style.

What You'll Learn

In this mini-project, you'll learn how to build a complete API authentication system from scratch, including:

Understanding JWT (JSON Web Token) authentication and how it works

Implementing secure password handling with Rails' has_secure_password

Creating a stateless authentication system that scales well

Building service objects for clean, maintainable authentication code

Implementing proper error handling and security best practices

Writing comprehensive tests for your authentication system

Project Overview

This mini-project will guide you through building a complete API authentication layer for Rails, including:

1. JWT Authentication

Learn how JSON Web Tokens work and how to implement them in your Rails API. You'll understand the structure of JWTs, how they're encoded and decoded, and how to use them for stateless authentication.

2. Service Objects

Implement clean, maintainable authentication code using service objects. You'll create services for user authentication and request authorization that are easy to test and extend.

3. Security Best Practices

Learn how to properly handle passwords, minimize information leakage, and implement consistent error handling throughout your API.

4. Comprehensive Testing

Write thorough tests for your authentication system, including request specs and controller tests using RSpec and FactoryBot.

Why This Mini-Project?

While there are many authentication gems available for Rails, building your own authentication layer provides several benefits:

Deep understanding of how authentication works

Complete control over your authentication flow

Flexibility to customize for your specific needs

No dependencies on third-party gems that might become outdated

Valuable skills that will make you a better Rails developer

What You'll Build

By the end of this mini-project, you'll have a complete API authentication layer that includes:

• A User model with secure password handling
• A JsonWebToken class for token encoding and decoding
• Service objects for user authentication and request authorization
• Controller concerns for request authentication and error handling
• A sessions controller for user login
• Comprehensive tests for all components

This authentication layer is production-ready and can be easily integrated into any Rails API project. It's also designed to be extensible, so you can add features like refresh tokens, token blacklisting, or role-based authorization as your needs evolve.

Prerequisites

To get the most out of this mini-project, you should have:

• Basic knowledge of Ruby and Rails
• Familiarity with RESTful APIs
• Understanding of HTTP status codes and headers
• Basic knowledge of testing with RSpec

Don't worry if you're not an expert in all these areas. The mini-project includes detailed explanations and step-by-step instructions to help you understand each concept.