2025 Auth Mfe Blog 1 Intro

Beginner-friendly series to learn Authentication Micro-Frontends (MFE) step by step. We’ll use React, TypeScript, Vite, React Router, and MSW. No backend required to start!

Table of Contents

1. Introduction
2. Functional Scope
3. Technical Scope
4. React Detailed Primer (10-minute)
5. Architecture Diagram (Blogger-safe)
6. Prerequisites & Setup (PowerShell)
7. Create Workspace & First Project
8. Key Beginner Insights
9. What’s Next

Introduction

If you’ve ever logged into a website, you’ve already experienced authentication. But in modern web apps, authentication is rarely coded once and forgotten — instead, companies build dedicated Authentication Micro-Frontends (Auth MFEs) to handle login, logout, user sessions, and security checks in a reusable way.

Why “micro-frontend”? Imagine a LEGO block: each block (or MFE) can be plugged into different apps. With Auth MFE, we can plug login/logout into a banking app, a shopping site, or an internal dashboard, without rewriting the whole thing.

In this series, you’ll build a tiny, beginner-friendly Auth MFE from scratch. You won’t need a real backend, because we’ll simulate it using MSW (Mock Service Worker). That means you can focus on learning React and authentication concepts without getting stuck in server setup.

Functional Scope

In Blog #1, our goal is not to build the whole login system, but to:

• Understand what an Auth MFE does in the real world.
• Set up a project structure with Vite + React + TypeScript.
• Learn React basics with practical mini-examples.
• Prepare for Blog #2, where we’ll code login/logout flows step by step.

By the end of this blog, you’ll have a running React project that can display mock pages and is ready to expand into a real Auth MFE.

Technical Scope

We’ll use a modern frontend stack that’s very common in professional projects:

• Vite: Super-fast build tool to scaffold and run React apps.
• React: UI library for building components.
• TypeScript: Adds type safety and better tooling.
• React Router: Handles navigation (login → profile → logout).
• MSW: Mocks backend APIs so we can develop without servers.

This combination is not only beginner-friendly but also matches what many companies use in production today.

React Detailed Primer (10-minute)

If you’re new to React, don’t worry — let’s take 10 minutes to cover the basics.

1. Components

Think of components as reusable pieces of UI. Example:

function Hello() {
  return <h1>Hello World!</h1>;
}

2. Props

Props are like function parameters for components:

function Greet(props) {
  return <h2>Hello, {props.name}!</h2>;
}

3. State

State lets components remember values:

import { useState } from "react";

function Counter() {
  const [count, setCount] = useState(0);
  return (
    <div>
      <p>Count: {count}</p>
      <button onClick={() => setCount(count + 1)}>+1</button>
    </div>
  );
}

These three — Components, Props, and State — are the building blocks of React.

Architecture Diagram (Blogger-safe)

Here’s a simple conceptual diagram of our Auth MFE:

    [ User ]
       |
    [ Login Page ] → [ React Router ] → [ Mock Backend via MSW ]
    

Instead of connecting to a real server, we intercept calls and return fake user data. This is perfect for learning.

Prerequisites & Setup (PowerShell)

You’ll need Node.js installed. Then open PowerShell and run:

npm create vite@latest auth-mfe -- --template react-ts
cd auth-mfe
npm install
npm run dev

Visit http://localhost:5173 to see your app running.

Create Workspace & First Project

Open the project in VS Code or IntelliJ. The src folder contains:

• App.tsx — main React component
• main.tsx — entry point
• index.css — styles

Try editing App.tsx to say “Hello Auth MFE” instead of “Hello World.” That’s your first customization 🎉.

Key Beginner Insights

• Start small: don’t jump into JWT tokens or OAuth yet. Focus on basics.
• Mock before real: using MSW avoids backend complexity while learning.
• React is like LEGO: build small components and combine them.
• Practice beats theory: tweak the code, break it, and fix it.
• Don’t fear TypeScript: it helps you catch mistakes early.

What’s Next

In Auth MFE Blog #2, we’ll move from setup to coding:

1. Build 10 incremental examples (ex1 → ex10).
2. Add login, logout, and profile screens.
3. Use React Router to navigate between pages.
4. Simulate user authentication with MSW.

By the end of Blog #2, you’ll have a working Auth MFE that looks and feels real. And in Blog #3, we’ll add tests (BDD + MSW + Cypress).