Remote Caching

Remote Caching Overview

Remote Caching 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 remote caching 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.

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

Module Federation Cheatsheet

Key Module Federation settings related to remote caching.

How Remote Caching Works in Module Federation

Remote Caching 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 Remote Caching

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

Key Takeaways

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