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Expo pins SDK 58's stable release to React Native 0.88 shipping first
The beta runs three to four weeks with React Native 0.88 as a release candidate, and Expo says stable follows once 0.88 lands. Most of what teams have to test is iOS 27 behaviour: scene life cycle, resizable windows, orientation locks.
The Engineer · Build desk
What happened
- Expo opened the SDK 58 beta and said the test period will last three to four weeks, with fixes and improvements released continuously while it runs.
- SDK 58 is built for iOS 27, which requires the UIKit scene-based life cycle and makes iPhone apps resizable for anything compiled against that SDK.
- On iOS 27, requireFullScreen no longer opts an app out of resizing, and ScreenOrientation.lockAsync may have no effect while the app is resizable.
- Full release notes arrive with the stable release; during the beta the scope and breaking changes sit in per-package changelogs in the expo/expo repository.
Compiled by The EngineerSomething wrong?How this is made
Why it matters
- constraint The upgrade runs on React Native's schedule. The stable build arrives after React Native 0.88 does, and that date belongs to React Native.
- exposure Orientation-locked and screen-measuring code can fail without crashing once the window resizes, so a QA pass that only exercises a fixed portrait simulator will sign off an app that lays out wrong.
- decision Anyone who wants iOS 27 behaviour in the store this month has to decide whether to ship production builds on a React Native release candidate.
- cost Teams without a local Xcode 27 install have to wait for it: the hosted build images that carry the iOS 27 support are still pending.
iOS 27's scene requirement is the part that touches native code. Expo apps now use the scene-based life cycle so they launch correctly on iOS 27, landed in #46733 [10]. That changes how app delegate callbacks are delivered, and Expo tells anyone who customises AppDelegate.swift to read the scene life cycle migration guide [11]. A stock AppDelegate should behave as it did. A customised one is the first thing to put on a device.
Resizing lands in layout code: Expo packages stopped reading geometry from UIScreen.main across five referenced pull requests, and expo-modules-core now exposes scene-aware geometry helpers [12][22][13]. The requireFullScreen config plugin has been updated for the new behaviour [15]. App code and third-party modules that still ask UIScreen.main for a width sit outside that change.
React Native 0.88 has not shipped, so the beta carries the release candidate [4]. Expo says it will move to the stable release when 0.88 ships and put out SDK 58 shortly after [5]. It also says you can ship with the beta now if you want iOS 27 support in your app today [3]. Doing that through hosted builds needs an image that is not there yet: EAS Build images with Xcode 27 and the SDK 58 toolchain are described as coming soon, and the latest image ships Xcode 26.6 [17].
Distribution during the beta is narrow. Expo Go for SDK 58 is available only through Expo CLI, for Android devices and emulators and iOS simulators, and through eas go for iOS devices [7]. The App Store and Google Play builds update shortly after the stable release, which Expo says leaves time to upgrade before the store version drops SDK 57 support [8].
Xcode 27 replaces Simulator.app with Device Hub, and Expo CLI already detects Device Hub, boots simulators through it, and focuses the right device using its devices:// deep link [18]. Local scripts that opened Simulator.app by name are outside that and need their own fix.
expo-app-intents exposes Apple App Intents to Expo apps [19]. Intent types must be declared in Swift inline modules inside an app-intents directory, because Apple's build-time metadata extraction only sees code in the app target [20]. The package delivers invocations to JavaScript and stores entity values, and it is in alpha [21].
What to watch
- React Native 0.88's stable tag, since Expo says SDK 58 stable follows shortly after it.
- The arrival of EAS Build images carrying Xcode 27 and the SDK 58 toolchain.
- The iPhone Duo SDK, which Expo says will bring further integration work during the beta.