Dynamic Remotes

Dynamic Remotes Overview

Dynamic Remotes 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 dynamic remotes 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.

// remote (webpack.config.js)
const { ModuleFederationPlugin } = require('webpack').container;

module.exports = {
  plugins: [
    new ModuleFederationPlugin({
      name: 'catalog',
      filename: 'remoteEntry.js',
      exposes: {
        './ProductList': './src/ProductList',
      },
      shared: ['react', 'react-dom'],
    }),
  ],
};

A remote exposes modules through remoteEntry.js so hosts can load them at runtime.

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

Module Federation Cheatsheet

Key Module Federation settings related to dynamic remotes.

How Dynamic Remotes Works in Module Federation

Dynamic Remotes 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.

A remote exposes modules through remoteEntry.js so hosts can load them at runtime.

• 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 Dynamic Remotes

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

Common Mistakes

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

Key Takeaways

• Dynamic Remotes is a core part of working effectively with Module Federation.
• Start small and keep dynamic remotes focused on a single responsibility.
• Apply consistent patterns so dynamic remotes scales across your project.
• Test and document dynamic remotes to keep it maintainable over time.