2026-05-12 · #29
React Native Weekly #29 Expo SDK 56 Beta, View Transitions RN 0.86, SWC Flow Support and more
Expo SDK 56 Beta Delivers 50%+ Faster iOS Builds#
The Expo SDK 56 beta has been released, bringing over 50% faster iOS builds via pre-compiled XCFrameworks and 40% faster Android cold starts.
iOS native modules have been largely rewritten to communicate directly with JSI through Swift/C++ interop, eliminating the need for an Objective-C++ intermediate layer.
We just cut the SDK 56 beta 😅 ◆ 50%+ faster iOS builds (precompiled XCFrameworks) ◆ 40% faster cold starts on Android ◆ Expo UI is stable ◆ iOS widgets are stable ◆ expo-router rebuilt from scratch ◆ Inline native modules ◆ Brownfield multi-app support The obvious
I also wrote an article exploring how Expo might evolve going forward, based on what’s coming in SDK 56.
Expo SDK 56ベータの内容と、そこから感じた今後のExpoの方向性について書きました! Expo SDK 56ベータから読み解く、Expo・React Nativeの「ネイティブ志向」な進化｜kazutoyo@ TellerNovel zenn.dev/tellernovel_inc/artic… #zenn
Expo UI Reaches Stable Release#
Expo UI has been released as stable, with Jetpack Compose support now brought up to the same level as SwiftUI.
Worklets support has also been added, enabling direct control of native SwiftUI/Jetpack Compose state from JS on the UI thread.
This makes it possible to build truly controllable form controls — like flicker-free text inputs.
Lots to unpack here! In this Expo UI release, we focused on bringing Jetpack Compose support to parity with SwiftUI. We also added worklets support, so you can drive native SwiftUI/Jetpack Compose state from JS on the UI thread, making sync patterns and truly controlled form twitter.com/expo/status/205247…
ExpoでUIをSwiftで書いて、ロジック管理だけReactに寄せれるってこと…！ twitter.com/kazutoyo/status/20…
react-native-web Becomes Optional in Expo SDK 56#
In Expo SDK 56, the expo package no longer requires react-native-web as a mandatory dependency.
This follows the SDK 55 move to rewrite log-box using only react-dom, and the next step will be making RNW optional in expo-router as well.
In Expo SDK 56, the `expo` package no longer requires react-native-web installed. We rewrote the log-box to be react-dom only in 55. Next step is to make RNW optional in expo-router. This will allow for full universal apps with react-strict-dom `<html.div>` instead of `<View>`
Type Definitions Added to CNG Plugins in Expo SDK 56#
Expo SDK 56 adds type definitions to all Expo packages that have CNG plugins.
Simply importing from expo-x/plugin gives you autocomplete and deprecation warnings in app.config.ts.
This is not in the changelog, but I added types for all expo packages with CNG plugins in this release. Autocomplete, JS doc, deprecations, directly in your app.config.ts Just import x from "expo-x/plugin" 👀 twitter.com/expo/status/205247…
SWC Adds Flow Support, Enabling Full Babel Replacement#
SWC has added Flow support, making it possible to fully replace Babel in React Native projects.
It’s implemented as a drop-in replacement for Metro transform workers, delivers roughly 8x faster builds, and includes built-in support for Reanimated and Expo.
Finally SWC has Flow support, meaning Babel can be fully replaced in React Native projects. I made a drop-in replacement for metro transform worker. Around 8x faster, so main bottleneck is now metro itself. Reanimated and expo support built-in. Link below 👇
Reanimated 4.3.1 Fixes Deadlock with Hades#
React Native Reanimated 4.3.1 and Worklets 0.8.3 have been released, fixing a race condition and removing a code path that caused deadlocks with Hades, Hermes’s garbage collector.
Users experiencing unexplained crashes or ANRs are encouraged to upgrade.
Last week we released Reanimated 4.3.1 and Worklets 0.8.3 - where we fixed some race-conditions and removed a code path, which could make the Hermes and its garbage collector, Hades, go into a deadlock. If you were suffering vague crashes or ANRs, make sure to upgrade!
View Transitions Added to React Native 0.86-RC#
The release notes for the React Native 0.86 release candidate have been found to include View Transitions.
It appears to be an experimental feature at this point.
Pretty interesting to see view transitions in the React Native 0.86-RC release notes. Probably experimental but more animation primitives are always welcome. github.com/facebook/react-nati…
react-native-quick-base64 v3.0.0 Is 2–3x Faster#
react-native-quick-base64 v3.0.0 has been released, delivering approximately 2–3x faster Base64 encoding/decoding compared to v2.
The improvement was made possible by a contribution from @grzywn.
[email protected]リリース。パフォーマンスが２〜３倍になりました github.com/craftzdog/react-nat…
agent-device v0.14 Achieves 100% Pass Rate with Codex#
agent-device v0.14 features a completely revamped skill set and introduces simple instructions via the help command.
In tests using skillgym, the pass rate improved from 41.7–54.2% with cheaper models to 100% with Codex.
In 𝚊𝚐𝚎𝚗𝚝-𝚍𝚎𝚟𝚒𝚌𝚎 v0.14 we completely reworked our skills: simpler instructions through 𝚑𝚎𝚕𝚙 command. But how did we know it’s better? We added tests with skillgym. Started at 41.7–54.2% passing on cheap models, and Codex got it to 100% while adding more cases.
agent-cdp v1.4.0 and Rozenite v1.8.0 Enhance Debugging and Monitoring Tools#
agent-cdp v1.4.0 enables agents to inspect Performance API entries and execute live code, while Rozenite v1.8.0 adds support for the Network Activity plugin in React Native DevTools via react-native-nitro-fetch.
Even when mixing nitro-fetch with built-in APIs, all network logs are consolidated in a single unified view.
If your agent ever wanted to inspect Performance API entries or execute code to debug things live, it can now do that with agent-cdp v1.4.0 P.S. We also support network logs now, in case you missed it 🫡
Rozenite v1.8.0 brings react-native-nitro-fetch to React Native DevTools via the Network Activity plugin. You can mix both nitro-fetch and built-in APIs - you'll see both in a unified network log.
npx serve-sim Lets You Inspect iOS Simulator Apps from a Browser#
A new npx serve-sim command has been released, allowing you to inspect elements of any app running in the iOS Simulator directly from Codex or a browser.
It enables agents to debug network requests and inspect elements in iOS apps.
You can now 'inspect element' for any iOS app directly in Codex or the browser! ~ / npx serve-sim S/O @rounak for the contribution 🚀
I gave Codex the ability to open Chrome DevTools for any iOS website No more opening Safari just to inspect element or debug network requests. Just tell your agent to run: ~ / npx serve-sim
SimCam Adds Camera Support to the iOS Simulator#
A new tool called “SimCam” has been released that adds camera functionality to the iOS Simulator.
It supports both front and back cameras, with each camera source controllable from the menu bar.
The iOS Simulator has never had a camera. SimCam fixes that! Your simulator can use front, back or both cameras, each with its own source you control from the menu bar.
React Conf Japan 2027 Announced for Tokyo#
React Conf Japan has been announced for April 24, 2027 in Tokyo.
Details are coming soon.
📣 Save the date!! React Conf Japan April 24, 2027 — Tokyo 🇯🇵 More details soon.
One More Thing#
SWC now supports Flow and can fully replace Babel — and that ~8x speedup figure is pretty eye-catching!
Swapping out build tooling has a big impact on the whole ecosystem, so I’m curious to see how well those numbers hold up in real-world projects.