App.js 2026 just wrapped up in Kraków with over 500 React Native developers gathering for two days of ecosystem updates. We shared some major announcements, including our new production performance library and a year's worth of platform improvements.
Why React Native fits the AI development wave
AI changed who builds apps and how quickly they ship. React Native and Expo happened to be positioned well for this shift, thanks to decisions made years before anyone thought about prompting models to write code.
The foundation matters here. Building with JavaScript, TypeScript, and React gives AI models massive training datasets to work from. When a model generates Expo code, it's drawing from years of public React and TypeScript repos, not just a few examples.
Documentation plays a bigger role than you might expect. Over the past year, docs commits made up the largest portion of changes to the Expo repo. That documentation becomes training data, so better docs directly improve how well models write Expo apps.
Universal deployment helps too. When someone prompts an app builder ("make me an app that streams my radio station"), the model doesn't need platform-specific knowledge. It can default to Expo, build once, and target everything.
The community amplifies all of this. When you solve a React Native problem and write about it, both developers and models learn from your solution. This creates a compounding effect across the ecosystem.
What we're working on next
Agents need feedback loops. When an agent can run an app, interact with it, and verify it works correctly, it can debug and iterate independently. Tools like Argent from Software Mansion and Agent Device from Callstack that let agents screenshot, tap, and inspect running apps enable this workflow.
Speed remains important. Since writing code got faster for most developers, the bottleneck shifted to builds, distribution, and boot times. Much of our upcoming work targets making these parts as fast as possible.
We want the default path to produce good results. Tools like Expo Router should give you a polished, native-feeling app without extra configuration.
A year of major releases
Here's what shipped over the past twelve months:
TV app support extends universal apps to living rooms. You can share about 85% of your code between mobile, Apple TV, and Android TV.
Expo UI reached stability in Expo SDK 56 with a default template. It renders real SwiftUI and Jetpack Compose widgets from a single JavaScript API, letting you use OS primitives without writing native modules.
Expo Launch provides a web-based flow for getting apps to TestFlight, App Store, and web without manually writing config files.
The Expo MCP server connects agents to your project's SDK version, config, dev server, and cloud services. It's free for all Expo accounts. The simulator integration stands out: multimodal agents can screenshot and interact with running apps, pull React Native DevTools data, and debug build failures using TestFlight and crash reports.
Expo skills contains official skills for building, deploying, and debugging apps. It covers UI development, deployment, SDK upgrades, DOM components, and dev clients. With deep Expo Router integration, agents can generate native-feeling UIs in single attempts.
Expo widgets simplifies building home screen widgets and live activities on iOS without native code.
Expo Router v56 adds more native navigation primitives: native toolbars, link transitions, and platform-specific behaviors. The demo showed an accessory sliding into the tab bar on scroll, smooth shared element transitions, and a search bar that collapsed the tab bar while floating above the keyboard.
Expo SDK 56 focuses on performance
SDK 56 prioritizes speed improvements. Pre-compiled binaries accelerate builds, and Android cold start times dropped 40%. Hermes V1 is now default, along with numerous smaller optimizations.
The new starter app makes a bigger impact than expected. Fresh projects now open with a polished first screen, including clean entrance animations and built-in explore tab animations.
Starting from something that looks good changes how development feels from day one.
The expo.dev dashboard got a complete redesign with better organization and more data. EAS Workflows added prepackaged jobs: GitHub comment jobs that report builds and updates on PRs, Apple device registration jobs for ad hoc provisioning profiles, and approval jobs that add human checkpoints to workflows.
Introducing Observe for production performance
The biggest announcement was Observe, our new open source library for capturing real performance metrics from production apps.
Local development doesn't match user reality. You test on good Wi-Fi with a fast device. Users have every kind of device and network imaginable. Performance problems hide in that gap.
Observe tracks the complete user journey: from tapping your app icon to actually using it. It measures launch time, bundle load time, time to render, and time to interactive. Each measurement includes device metadata, app version, and location. Time-to-interactive metrics also capture device state: battery level, Wi-Fi status, and dropped frame counts. You can attach custom objects to track screen-specific data.
Per-screen metrics answer the most common developer questions. Mobile apps behave like SPAs, making it hard to identify slow screens. Since every Expo Router route has a URL, Observe can report metrics per page. After rebuilds, you see cold and warm time-to-render and time-to-interactive for each screen.
Version tracking gets clearer too. React Native apps have native layers and JavaScript bundles, making version identification tricky. Observe shows exactly which version each user is running. In a two-version example (1.0.0 and 1.0.1), you see installs and active users for each version.
Custom event tracking lets you capture any serializable data.
Reading the data uses AI assistance. Instead of scanning dashboards for problematic metrics, you can ask questions in plain text and let agents analyze the data. Observe ships with skills for installation and metric interpretation.
Expo Observe is in public beta, free for up to 10,000 monthly active users for at least three months. It will become a paid service after that. We want feedback while preparing for general availability.
More features are coming in future releases.
Building is getting more accessible
Seth Webster's closing talk, "It's a great time to be a builder," argued that one person with good judgment and the right tools can now create what used to require ten-person teams.
Many React developers once saw mobile development as requiring Objective-C or Java knowledge to ship real apps. React Native and Expo removed that barrier. If AI is opening similar doors for more developers, that's worth celebrating.
Check out the recorded talks from Software Mansion. The full two days feature some of the best people working in React Native. Thanks to Software Mansion and all sponsors who made the conference happen.
Now go build something! Join us in Portland at Chain React Conf.
This post is based on content from the Expo blog. Follow @expo for more React Native content.
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