App Links (Android)

App Links let Android users tap a link and open your app directly, without a disambiguation dialog. Tolinku automatically hosts the Digital Asset Links file for your Appspace’s domain.

How it works

When a user taps a link to your Tolinku domain (e.g. https://myapp.tolinku.com/merchant/abc123):

1. Android checks the assetlinks.json file at https://myapp.tolinku.com/.well-known/assetlinks.json.
2. If the app’s package name and signing certificate match, Android opens your app and passes the URL via an Intent.
3. If the app is not installed, Android opens the URL in the browser, where the user sees your landing page.

Setup

1. Configure your Android settings in Tolinku.

   Go to Appspace Settings > Android and enter:

   • Package Name: Your app’s package name (e.g. com.example.myapp)
   • SHA-256 Certificate Fingerprint(s): The SHA-256 fingerprint of your app’s signing certificate

   You can add multiple fingerprints (comma-separated) for debug and release certificates.

2. Add the intent filter to your AndroidManifest.xml.

   <activity android:name=".DeepLinkActivity"
       android:exported="true">
       <intent-filter android:autoVerify="true">
           <action android:name="android.intent.action.VIEW" />
           <category android:name="android.intent.category.DEFAULT" />
           <category android:name="android.intent.category.BROWSABLE" />
           <data
               android:scheme="https"
               android:host="myapp.tolinku.com" />
       </intent-filter>
   </activity>

   The android:autoVerify="true" attribute tells Android to verify domain ownership via the assetlinks.json file.

3. Handle incoming links in your Activity.

   See the Android SDK guide for code examples.

Digital Asset Links file

Tolinku generates and serves the assetlinks.json file automatically at:

https://your-domain/.well-known/assetlinks.json

Example output:

[
  {
    "relation": ["delegate_permission/common.handle_all_urls"],
    "target": {
      "namespace": "android_app",
      "package_name": "com.example.myapp",
      "sha256_cert_fingerprints": [
        "AA:BB:CC:DD:EE:FF:00:11:22:33:44:55:66:77:88:99:AA:BB:CC:DD:EE:FF:00:11:22:33:44:55:66:77:88:99"
      ]
    }
  }
]

Note

Unlike iOS Universal Links, Android App Links apply to all paths on the domain. You do not need to enable App Links per-route; the intent filter in your manifest controls which paths your app handles.

Getting your SHA-256 fingerprint

Debug certificate

keytool -list -v -keystore ~/.android/debug.keystore -alias androiddebugkey -storepass android

Look for the SHA256: line in the output.

Release certificate

keytool -list -v -keystore your-release-key.jks -alias your-alias

Google Play App Signing

If you use Google Play App Signing (recommended), find your SHA-256 fingerprint in the Google Play Console:

1. Go to Setup > App signing
2. Copy the SHA-256 certificate fingerprint under “App signing key certificate”

Caution

If you use Google Play App Signing, you must use the fingerprint from the Play Console (the app signing key), not your upload key. The upload key is different from the key Google uses to sign your APK.

Custom domains

If you use a custom domain, Tolinku serves the assetlinks.json file on that domain as well. Update your intent filter to include the custom domain:

<intent-filter android:autoVerify="true">
    <action android:name="android.intent.action.VIEW" />
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" />
    <data android:scheme="https" android:host="myapp.tolinku.com" />
    <data android:scheme="https" android:host="links.myapp.com" />
</intent-filter>

Troubleshooting

Links open in the browser instead of your app:

• Check that android:autoVerify="true" is set on the intent filter.
• Verify the package name and SHA-256 fingerprint are correct in Appspace Settings.
• If using Google Play App Signing, ensure you are using the app signing key fingerprint (not the upload key).
• Run the verification check:

  adb shell pm get-app-links com.example.myapp

  The output should show your domain as verified.

Verification fails:

• Ensure the assetlinks.json file is accessible. Test by visiting https://your-domain/.well-known/assetlinks.json in a browser.
• The file must be served with Content-Type: application/json and accessible without redirects.
• If you recently added or changed fingerprints, it may take a few minutes for the change to take effect.

Links work but show a disambiguation dialog:

• This means autoVerify failed. Check the steps above.
• On some Android versions, the user may need to manually set your app as the default handler in Settings > Apps > Default apps > Opening links.

Testing

To verify App Links during development:

1. Install your app on a device or emulator.
2. Run the verification command:

   adb shell pm verify-app-links --re-verify com.example.myapp

3. Check the verification status:

   adb shell pm get-app-links com.example.myapp

4. Open a link using adb:

   adb shell am start -a android.intent.action.VIEW \
     -d "https://myapp.tolinku.com/merchant/abc123" com.example.myapp

Tip

Use Google’s Digital Asset Links Tester to verify your assetlinks.json file is correctly formatted.