SYSTEM Cited by 1 source
callstack/react-native-brownfield¶
@callstack/react-native-brownfield is an open-source npm
package from Callstack that
generalises the "React Native as a package" integration
pattern — embedding React Native into an existing large
native iOS/Android codebase without requiring a full-app
rewrite.
What it solves¶
Integrating React Native into a mature native app (brownfield integration, per concepts/brownfield-rn-integration) exposes three problems:
- Native-dependency conflicts — RN or community packages pulling native deps in versions that disagree with the main app's.
- No clear separation — git-submodule-style integration doesn't enforce isolation between RN and legacy code.
- Bad developer experience — requiring every RN contributor to build the full native app (including Xcode / Android Studio setup) is a friction barrier, especially for web engineers.
The brownfield package generalises the solution:
- Packages RN's root component + initialisation logic behind a simple SDK interface.
- Supports being consumed by a standalone developer app (greenfield RN, fast iteration) and by the native framework SDK embedded in the legacy native app.
- Provides the RN lifecycle plumbing (bridge / JSI initialisation, JS-bundle loading, view mounting) so host apps don't reinvent it.
Origin¶
The Zalando 2025-10 post credits Callstack explicitly: "A lot of this work has been open sourced by our friends at Callstack in a simple package that you can use yourself!" The patterns Zalando canonicalises (Entry Point + Developer App + Framework SDK) match the package's abstractions and are its canonical production validation.
Seen in¶
- sources/2025-10-02-zalando-accelerating-mobile-app-development-with-rendering-engine-and-react-native — canonical wiki production case. Zalando's Mobile Framework SDK builds on this pattern; Callstack is credited as the upstream.