Version Matching

In this lesson you will learn version matching in Module Federation, why it matters within shared dependencies, and how to use it correctly with clear, copy-ready examples.

Version Matching Overview

Version Matching lets you structure Module Federation work so it stays readable, testable, and easy to scale. Instead of ad-hoc code, you follow a clear pattern that other developers can recognise immediately.

The key is to keep version matching focused and predictable. Start from the minimal example here, then layer in only the complexity your feature actually needs.

new ModuleFederationPlugin({
  name: 'shell',
  shared: {
    react: { singleton: true, requiredVersion: '^18.2.0' },
    'react-dom': { singleton: true, requiredVersion: '^18.2.0' },
  },
});

Marking shared libraries as singletons ensures one React instance is used across all micro frontends.

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

Module Federation Cheatsheet

Key Module Federation settings related to version matching.

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 Version Matching Works in Module Federation

Version Matching 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.

Marking shared libraries as singletons ensures one React instance is used across all micro frontends.

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 Version Matching

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

Key Takeaways

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

Pro Tip

When you get stuck on version matching, reduce it to the smallest reproducible example first — most Module Federation issues become obvious once the noise is gone.