.NET MAUI Deep Linking

Platform Gotchas

Android

AutoVerify = true is required on the IntentFilter for App Links (not just deep links). Without it, Android shows a disambiguation dialog instead of opening your app directly.
Handle intent in both OnCreate and OnNewIntent. OnCreate fires for cold starts; OnNewIntent fires when the app is already running. Missing either means links silently fail in one scenario.

// ❌ Only handles cold-start links
protected override void OnCreate(Bundle? savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    HandleDeepLink(Intent);
}

// ✅ Handles both cold-start and warm-start links
protected override void OnCreate(Bundle? savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    HandleDeepLink(Intent);
}
protected override void OnNewIntent(Intent? intent)
{
    base.OnNewIntent(intent);
    HandleDeepLink(intent);
}

SHA-256 fingerprint must match the signing key used for the build you're testing. Debug and release builds use different keys — update assetlinks.json accordingly or verification silently fails.
Test verification status with:
```
adb shell pm get-app-links com.example.myapp
```
Look for verified status, not just ask.

iOS

⚠️ Universal Links do NOT work in the Simulator. You must test on a physical device.
AASA changes take up to 24 hours to propagate through Apple's CDN (iOS 14+). During development, use the ?mode=developer query param or Apple's CDN diagnostics: swcutil dl -d example.com.
Handle all three entry points: FinishedLaunching, ContinueUserActivity, and SceneWillConnect. Missing any one causes links to fail for specific app states (cold start, background resume, or scene-based launch).
applinks: prefix is required in the Associated Domains entitlement. Writing just example.com instead of applinks:example.com silently fails.

Common Mistakes

Forgetting `MainThread.BeginInvokeOnMainThread`

Deep link callbacks can fire on background threads. Shell navigation must run on the main thread.

// ❌ May crash — GoToAsync called off the main thread
static void HandleUniversalLink(string? url)
{
    if (string.IsNullOrEmpty(url)) return;
    Shell.Current.GoToAsync(MapToRoute(url));
}

// ✅ Dispatch to main thread
static void HandleUniversalLink(string? url)
{
    if (string.IsNullOrEmpty(url)) return;
    MainThread.BeginInvokeOnMainThread(async () =>
        await Shell.Current.GoToAsync(MapToRoute(url)));
}

Route not registered before navigation

Register Shell routes in AppShell constructor before any deep link can fire. If the route doesn't exist, GoToAsync throws silently or navigates to root.

Custom URI schemes vs. App Links / Universal Links

| Approach | Verified | Fallback to browser | Recommended | |---|---|---|---| | Custom URI scheme (myapp://) | No | No | Only for app-to-app communication | | Android App Links (https://) | Yes | Yes | ✅ Production web links | | iOS Universal Links (https://) | Yes | Yes | ✅ Production web links |

⚠️ Custom URI schemes are not verified — any app can register the same scheme. Use https:// App Links / Universal Links for user-facing URLs.

Debugging Checklist

[ ] Android: IntentFilter has AutoVerify = true on MainActivity
[ ] Android: assetlinks.json at /.well-known/ with correct SHA-256 for current signing key
[ ] Android: Intent handled in both OnCreate and OnNewIntent
[ ] Android: Verified with adb shell pm get-app-links
[ ] iOS: applinks:example.com in Associated Domains entitlement (not just example.com)
[ ] iOS: AASA file at /.well-known/apple-app-site-association with correct Team ID
[ ] iOS: All three lifecycle entry points handled
[ ] iOS: Tested on physical device (not simulator)
[ ] Shell routes registered before deep link callbacks fire
[ ] Navigation dispatched to main thread