Bidirectional communication between native app and multiple React Native mini-apps in a brownfield setup

[camilo5972]

Hi everyone!,

I’m currently using RNEF which uses the brownfield approach to export React Native mini-apps as AAR (Android) and XCFramework (iOS) so they can be integrated into native applications.

The setup works well for loading multiple independent mini-apps inside a larger native app. However, I’m now exploring how to implement bidirectional communication between the native app and each mini-app without having to fully embed RN dependencies on the native host side (especially for iOS).

The scenario:

Android: I can leverage React Native dependencies (already bundled in the mini-app) to use NativeModules/EventEmitters for bidirectional communication.
iOS: I’d like to avoid installing RN dependencies via npm and configuring the entire Xcode project with node_modules from the mini-app. Ideally, the mini-app framework should expose an interface for native ↔ RN communication out-of-the-box.

The goal:

• Pass contextual data from native → RN mini-app at launch (e.g., user session, config, feature flags).
• Allow the RN mini-app to send data/events back to native (e.g., analytics, triggers for native flows).
• Support runtime communication while RN is actively running — so the native side can send new data or receive events dynamically without reloading the mini-app.
• Avoid tight coupling to RN APIs in the host app so native developers don’t have to deal with the RN internals.
• Keep the solution portable so the same approach works on both Android and iOS.

Questions:

• Does the brownfield implementation in rnef already provide a recommended pattern or built-in API for this kind of communication?
• If not, what’s the best way to expose a communication layer from the mini-app framework without having to duplicate RN configuration in the native host project?
• On iOS specifically, is there a clean way to bridge data/events without installing React Native as a direct dependency in the host app?

Any advice, examples, or best practices would be very appreciated!

Thanks!

[thymikee]

Does the brownfield implementation in rnef already provide a recommended pattern or built-in API for this kind of communication?

No, it doesn't

If not, what’s the best way to expose a communication layer from the mini-app framework without having to duplicate RN configuration in the native host project?

One way would be to create a native module that's gonna handle that communication, e.g. backed by some storage so you can hook into the same mechanism from the native and RN app. The easiest way to get started would be to go with a local module with Bob library: https://callstack.github.io/react-native-builder-bob/create#local-library

On iOS specifically, is there a clean way to bridge data/events without installing React Native as a direct dependency in the host app?

You can use Notification Center