/expo-brownfield

Select versions before integrating

Keep the workflow version-aware rather than pinning every host to one SDK. Existing projects retain their SDK unless an upgrade is part of the task. New producers should use the current stable Expo release when the host and toolchain can support it.

Inspect and select

1. Read the producer's package.json and lockfile; record resolved expo, react-native, and expo-brownfield versions. Check the host's deployment targets, Xcode/Node versions, and native dependency graph, including any existing RN runtime.
2. For new work, check the Expo releases and SDK compatibility table. npm view expo dist-tags --json can confirm the current stable latest version. Do not infer stability from the highest SDK number or select canary/next by default.
3. Select an SDK compatible with the host's supported OS versions, modules, and build tools. Do not silently raise the host's minimum OS or swap its toolchain to satisfy a tutorial. If a constraint conflicts, explain the concrete choices before changing that product requirement.
4. Use that SDK's versioned Brownfield API docs and sdk-<major> native template. Install modules with npx expo install; run npx expo install --check before native builds. For an SDK upgrade, use expo-upgrade, preserve the host, and apply native diffs selectively.
5. Inspect the installed CLI's build:ios --help / build:android --help, plugin schema, generated Swift/Kotlin wrappers, and Package.swift. Flags, prebuilt defaults, import names, and binary products can change within a major release.

To scaffold a small new feature after those checks:

npx create-expo-app@latest my-project --template blank@latest
cd my-project
npx expo install expo-brownfield typescript @types/react

This avoids adding a Router shell just to export one component. For an existing Router app, preserve it and add the root-props adapter described in feature integration. If selecting an older SDK, use a verified template tag such as blank@sdk-55; the scaffolder's own @latest version does not determine the template's SDK. Commit the producer's lockfile for repeatable builds.

SDK requirements and build defaults

React Native prebuilt binaries and precompiled Expo modules are separate settings. Set React Native source mode on expo-brownfield's ios.buildReactNativeFromSource. Expo module precompilation is controlled by expo-build-properties' ios.usePrecompiledModules. Do not disable defaults as a generic build fix; first inspect the failing dependency and toolchain requirement.

In 57.0.18, precompiled builds suffix the generated package/product with its configuration (MyAppPackage-release or MyAppPackage-debug). They do not rename the generated Swift module: continue to import the configured target, such as MyBrownfield. Inspect the emitted manifest instead of constructing an assumed package path.

SDK 56 introduced additional brownfield capabilities carried into SDK 57, including experimental multiple isolated frameworks and registering host Turbo Module classes. Load the selected SDK's API and installed interfaces only when the task needs them. Do not enable experimental multi-framework support for a single feature or assume two independently packaged RN runtimes can be linked together without collision handling.

Sources: SDK requirements, SDK 57 Brownfield API, SDK 57 native template, SDK 56 brownfield additions, published Brownfield package.