App Links & Universal Links — Testing & Troubleshooting

Sanity checks (both platforms)

• Correct domain: use {YOUR_ID}.sddl.me or your verified custom domain.
• No redirects for metadata: AASA/assetlinks must respond with HTTP 200 (no 3xx) over HTTPS.
• Content-Type: serve JSON (e.g., application/json).
• Reinstall after changes: after editing entitlements (iOS) or fingerprints (Android), delete & reinstall.
• Cold-start restore: on app launch call SDDL resolve to fetch deferred payload (no link needed at launch).

# iOS — AASA direct
curl -i https://YOUR_DOMAIN/.well-known/apple-app-site-association
# Apple CDN check (replace domain)
# https://app-site-association.cdn-apple.com/a/v1/YOUR_DOMAIN

# Android — Digital Asset Links
curl -i https://YOUR_DOMAIN/.well-known/assetlinks.json

iOS — Universal Links

1. Associated Domains entitlement: present & installed on device. Reinstall after changes.
2. AASA availability: reachable at /.well-known/apple-app-site-association (no redirects).
3. Trigger from trusted surfaces: Notes, Mail, Safari (some in-app browsers rewrite links).
4. Simulator/Device open:

   xcrun simctl openurl booted "https://YOUR_DOMAIN/path"

5. Logs to watch: device Console in Xcode → filter swcd / associateddomain for entitlement & AASA parsing messages.

Android — App Links

1. Manifest intent-filter: includes android:autoVerify="true" for your host.
2. assetlinks.json: SDDL publishes based on package + SHA256 fingerprints (add Debug & Release).
3. Verification status:

   adb shell pm verify-app-links your.package.name
   # Optional reset
   adb shell pm reset-app-links your.package.name

4. Fire a test intent:

   adb shell am start -W \
    -a android.intent.action.VIEW \
    -d "https://YOUR_DOMAIN/path" your.package.name

5. Inspect mapping: adb shell dumpsys package your.package.name | grep -i intent-filter -n

Network/CDN pitfalls (both)

• Redirect chains: AASA/assetlinks must be direct 200 (avoid http → https or path rewrites).
• Headers: send JSON; disable auth & cookies; no HTML error pages for 404/403.
• Edge cache: metadata can be cached; after updates purge CDN or change URL host to {YOUR_ID}.sddl.me temporarily for tests.
• Firewall/AdBlock: can block first redirect; test on clean network and real device.

First-launch (deferred) context

To restore intent after install, the app should request resolution on cold start. With SDDL this is a single helper call (no need to pass the store URL back into the app).

• iOS: call resolve on first launch even if onOpenURL/NSUserActivity didn’t fire.
• Android: call resolve in onCreate and onNewIntent.
• Verify payload: log payload keys (campaign, ref, product) and assert routing.

Edge cases by surface

QA test matrix (copy-paste)

# Devices
- iPhone (latest iOS), iPad (optional), Android 12/13/14

# iOS
- Fresh install → tap link from Notes → app opens, routes correctly
- Reinstall after entitlement change → link works again
- AASA reachable (200, JSON, no redirects)
- From Messenger/Social → open in Safari → app opens

# Android
- Debug & Release fingerprints present
- adb verify-app-links → hosts verified
- Intent test opens app without chooser
- assetlinks.json returns 200 JSON

# Deferred
- Uninstall app → tap SDDL link → install → first launch → payload restored & routed

FAQ