explore-binary

Expo Explore

Explore maps your app: a screenshot of every screen, connected by the taps between them. On each pull request it captures the screens the PR changes, before and after, on EAS Simulator, and posts a visual review. On your Mac it can also run on a local simulator.

See a real report: euxy, a MIDI sequencer, reviewed by Explore. It is redeployed with the current Viewer on every merge to main.

Compare: each changed screen before and after, with the changed regions outlined on the after.

Paste this into Claude Code, Codex, Cursor, or any tool that can fetch a URL. In the Viewer, Hand off to AI fills it in for you:

Review the visual changes in PR #<number> of <owner>/<repo>.
Expo Explore report:
<report link>

Fetch the link first. It explains the report's JSON API. Go through the changed screens,
compare the before and after screenshots, and tell me which changes look intended and
which look like regressions. For each regression, name the source file to fix.

• To review a change: Expo SDK 57 or newer, with Expo Router (57 or newer) or React Navigation (6 or newer), and an Expo account, since Explore builds the app on EAS. An EAS build profile per platform: ios.simulator: true for iOS, android.buildType: apk (not a development build) for Android. Its EAS environment cannot have secret-visibility or file variables.
• To explore a build: a simulator build of any app, and a Claude Code or Codex login (or an API key). On a local simulator it needs no Expo account.
• Somewhere to run the app: EAS Simulator (in preview, join the waitlist), which CI uses; or a local simulator on your Mac: Xcode 26 or newer for iOS (the default devices are iPhone 17 models) and, for Android, the Android SDK with ANDROID_HOME set (emulator, platform-tools, cmdline-tools and a system image; to review a change, also build-tools and a JDK 17).
• Node.js 24.12 or newer. For CI, admin access to the GitHub repository.

Quick start

Paste this into Claude Code or Codex from your app's directory. It reviews a change to your app, before and after, or, if you point it to a build, maps every screen of that build:

Show me Expo Explore working on this app, with npx @expo/explore. If I point you to a
build (.app, .tar.gz, simulator .ipa, or .apk), explore it: follow
https://unpkg.com/@expo/explore/skills/explore-binary/SKILL.md. If this is not an Expo
project, ask me for a simulator build and explore that. Otherwise review a change to
this app: follow the "Review a change on this machine" section of
https://unpkg.com/@expo/explore/skills/explore-setup/SKILL.md. If the app cannot build
for the iOS Simulator on EAS yet, set that up (an EAS project, ios.bundleIdentifier, an
"explore" profile with ios.simulator: true) and ask me before you commit it. If I have
no EAS Simulator access, pass --simulator local (it needs Xcode; exploring an .apk needs
the Android SDK instead). If I have no uncommitted changes, change some text near the
top of a screen. If the app needs a sign-in, ask me for a test account the way the skill
describes, never for a password in chat. Open the report, and if I need to log in to
something first, tell me the command.

You need Node.js 24.12+. Reviewing a change needs an Expo account and an Expo SDK 57+ app with Expo Router or React Navigation: it is built on EAS and captured on EAS Simulator or, with Xcode, on a simulator on your Mac. Exploring a build needs a Claude Code or Codex login, and EAS Simulator or a simulator on your Mac; on your Mac, no Expo account. No API keys, no CI.

[!NOTE] EAS Simulator is in preview. Join the waitlist, or pass --simulator local to capture on a simulator on your Mac.

There are two ways to use Explore: review a change to your Expo app, which needs an Expo account, or explore an iOS or Android build of any app directly, which needs no Expo account when it runs on your Mac.

Review a change, from your app's directory:

1. Make the app buildable on EAS, if it is not yet:

   npx eas-cli@latest login
   npx eas-cli@latest init
   

   Then set ios.bundleIdentifier in your app config, add a simulator profile to eas.json, and commit. The "before" is where your branch left the default branch: on the default branch, your last commit.

   { "build": { "explore": { "ios": { "simulator": true } } } }
   

2. Edit some text near the top of a screen (Explore captures the first screenful) and run:

   npx @expo/explore capture                     # on EAS Simulator
   npx @expo/explore capture --simulator local   # or on a simulator on your Mac
   

   Explore builds your last commit and your uncommitted changes on EAS, captures the screens the changes can affect, before and after, and opens the report in your browser. The first run waits for an EAS build; later runs reuse it while your native code is unchanged. A local simulator is one Explore creates on your Mac and removes afterwards.

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