Nested Routes

Nested Routes is an important part of building production-ready Module Federation systems. This lesson explains what nested routes means, how it works, and how to apply it with practical examples you can reuse.

Nested Routes Overview

Nested Routes is a building block you will reach for often in Module Federation. It keeps related logic together and makes your intent obvious to reviewers and future maintainers.

When you learn nested routes properly, you avoid the guesswork that leads to bugs and rework. The example below shows the shape you will use in most real Module Federation projects.

const { ModuleFederationPlugin } = require('webpack').container;

module.exports = {
  plugins: [
    new ModuleFederationPlugin({
      name: 'shell',
      remotes: { catalog: 'catalog@http://localhost:3001/remoteEntry.js' },
      exposes: {},
      shared: { react: { singleton: true }, 'react-dom': { singleton: true } },
    }),
  ],
};

ModuleFederationPlugin configures which modules an app exposes, consumes, and shares.

Nested Routes Example

new ModuleFederationPlugin({
  name: 'app',
  filename: 'remoteEntry.js',
  exposes: { './Widget': './src/Widget' },
  remotes: { other: 'other@http://host/remoteEntry.js' },
  shared: { react: { singleton: true } },
});

Start from a minimal Nested Routes example and grow it only as needed.
Keep configuration explicit so Nested Routes behaves the same in every environment.
Name things clearly so teammates understand your Nested Routes at a glance.
Add tests around Nested Routes early to lock in expected behaviour.

Module Federation Cheatsheet

Key Module Federation settings related to nested routes.

Option	Example	Purpose
name	`name: 'shell'`	Unique container name
filename	`filename: 'remoteEntry.js'`	Remote entry manifest
exposes	`exposes: { './X': './src/X' }`	Modules a remote shares
remotes	`remotes: { app: 'app@url' }`	Remotes a host consumes
shared	`shared: { react: { singleton: true } }`	Deduplicate libraries
lazy load	`import('remote/Module')`	Load remotes on demand
Suspense	`<Suspense fallback={...}>`	Handle async loading

How Nested Routes Works in Module Federation

Nested Routes builds on Module Federation's ability to load code from another independently built and deployed application at runtime. Each app can be a host, a remote, or both.

ModuleFederationPlugin configures which modules an app exposes, consumes, and shares.

Remotes expose modules through a remoteEntry.js manifest.
Hosts declare remotes and import exposed modules dynamically.
Shared dependencies are deduplicated, ideally as singletons.
Each micro frontend builds and deploys on its own schedule.

Practical Guidance for Nested Routes

In production, nested routes needs careful version management and graceful failure handling. Align shared dependency versions and always render a fallback when a remote cannot load.

Concern	Recommendation
Shared versions	Use singletons with requiredVersion
Runtime errors	Wrap remotes in error boundaries and fallbacks
Deployment	Resolve remotes from a runtime manifest
Performance	Lazy-load remotes and cache remoteEntry.js

Common Mistakes

Copying nested routes snippets without understanding what each line does.
Skipping error handling and edge cases when wiring up nested routes.
Leaving nested routes untested, so regressions slip into production.
Over-engineering nested routes before you actually need the extra flexibility.

Key Takeaways

Nested Routes is a core part of working effectively with Module Federation.
Start small and keep nested routes focused on a single responsibility.
Apply consistent patterns so nested routes scales across your project.
Test and document nested routes to keep it maintainable over time.

Pro Tip

Pair nested routes with automated tests from day one. It is far cheaper to catch Module Federation regressions in CI than in production.