`@clerk/expo`: email link sign-in never completes on iOS — nothing forwards the callback URL to `Clerk.handle(url)`

[csandman]

This report was written by Claude, but the behavior and the source references were verified manually on real devices.

Email link (magic link) sign-in completes on Android but silently fails on iOS when using the prebuilt <AuthView /> from @clerk/expo/native. The app reopens on the callback URL and no session is created.

Filing without a minimal reproduction — apologies. This was found and verified on a production Expo app, and the analysis below is from reading the shipped SDK source, so I wanted to get it in front of you rather than sit on it. Happy to build a standalone repro if that's what it takes to get it looked at. Publishable key omitted for the same reason (production instance).

What happens

1. User starts email link sign-in from <AuthView /> in an Expo app.
2. The email opens Clerk's hosted page, which verifies and shows "Return to App".
3. That button deep-links back to the app on the bundle identifier scheme, e.g. com.myapp.bundleid://callback?flow_id=…&approval_token=….
4. Android: the session is created and the user is signed in.
5. iOS: the app comes to the foreground, but no session is created and the user is still signed out. No error surfaces.

Why (as far as I can tell)

clerk-ios completes the flow only from the callback's flow_id + approval_token — MagicLink.swift has no polling fallback — and its single intake path is Clerk.handle(_ url:). In AuthView.swift, the only caller is SwiftUI's .onOpenURL:

.onOpenURL { url in
  Task {
    do { try await clerk.handle(url) }
    catch { self.error = error }
  }
}

.onOpenURL is driven by the SwiftUI app lifecycle. Expo/React Native apps use the UIKit app delegate, so URLs arrive via application(_:open:options:) and that modifier never fires for the hosted SwiftUI view — nothing ever calls Clerk.handle(url).

Nothing in @clerk/expo bridges the gap: searching packages/expo on main returns zero references to onOpenURL, openURL, handleURL, or onNewIntent. Android is unaffected because clerk-android registers its own clerk:// intent filter and receives the callback natively — hence the platform split.

Expected behavior

@clerk/expo forwards inbound URLs to the native SDK on iOS the way clerk-android already does on Android, so email link sign-in completes on both platforms.

An ExpoAppDelegateSubscriber implementing application(_:open:options:) and calling Clerk.shared.handle(url) looks like it would cover it — Clerk.shared is public and already configured by ClerkNativeBridge, and returning false would leave the URL available to React Native's Linking, with clerk-ios's own URLHandlingCoordinator deduping any double handling. There's also a com.clerk.expo.native-sdk.did-configure notification that could handle a cold launch arriving before the SDK is configured.

Workaround

A local Expo module doing exactly the above. Worth noting for anyone else hitting this: the app also needs a route for the callback URL, or expo-router renders +not-found on top of it — on Android that means a "page does not exist" screen over a session that was just created successfully.

Environment

  System:
    OS: macOS 26.5.2
    CPU: (12) arm64 Apple M2 Pro
  Binaries:
    Node: 24.15.0
    npm: 11.12.1
    pnpm: 11.1.2
  npmPackages:
    @clerk/expo: ^3.7.1 => 3.7.1
    @clerk/shared: 4.25.0 => 4.25.0
    expo: ~57.0.12 => 57.0.12
    expo-router: ~57.0.12 => 57.0.12
    react: 19.2.3 => 19.2.3
    react-native: 0.86.2 => 0.86.2

Also reproduced on @clerk/expo@4.2.7, and packages/expo on main has the same gap.