# Who Need Help for Android This module is a native Android WebView shell for the Phoenix application. It keeps authentication cookies, LiveView WebSockets, MapLibre, and chat in the same trusted origin. Live location is sent by a user-started native foreground service with a persistent notification and Stop action, so it can continue while the Activity is minimized without requesting Android's background-location permission. The native tracking bridge uses `WebViewCompat.addWebMessageListener` with the exact configured origin and rejects messages outside the main frame. It does not expose a legacy `addJavascriptInterface` object to every frame. Remote notifications are opt-in. The Android bridge requests the Android 13+ notification permission, enables Firebase Messaging only after consent, and registers the Firebase Installation ID through the authenticated same-origin `/mobile/push-devices` endpoint. Data-only FCM messages are rendered by the app and may deep-link only to a validated relative path on the configured Who Need Help origin. Notification payloads do not contain chat text or exact location. Disabling the current device removes its server registration and unregisters the Firebase Installation; registration can be enabled again explicitly. Google authentication uses Android Credential Manager rather than an embedded OAuth user agent. The web page asks the native bridge to begin only after the user presses the visible Google button. Native code obtains a server-bound Google ID token with a one-time nonce and posts it directly to the same trusted Phoenix origin; the token is never returned to WebView JavaScript. The server client ID is obtained at runtime from the authenticated environment endpoint, so no Google client secret is compiled into any APK. Signing out also clears Credential Manager state. ## Verified build configuration - Android Gradle Plugin 9.3.0 - Gradle 9.6.1 - Android SDK Command-line Tools 22.0 - Android CLI 1.0.15857036 (embedded in the locked Command-line Tools archive) - AndroidX WebKit 1.16.0 - compileSdk / targetSdk 37 - Build Tools 37.0.0 - Java source and bytecode level 17 - minSdk 24 (project baseline, not an Android SDK requirement) The debug origin is not stored in the Dockerfile or Gradle project. Set `WNH_DEBUG_BASE_URL` in the repository's ignored `.env` file. The supplied local configuration uses loopback together with `adb reverse`; debug builds allow cleartext traffic, while the WebView still restricts in-app navigation to that one configured origin. The same ignored file supplies `WNH_TRACKING_MIN_TIME_MS` and `WNH_TRACKING_HTTP_TIMEOUT_MS`. The checked-in example preserves the original local client freshness and timeout behavior; these values are not claimed as measured production capacity settings. Release builds do not have a default server and cannot be produced unsigned. The repository reads non-secret version/origin settings from the selected ignored environment file, while the upload key and its randomized password stay outside the repository. Create that key once: ```sh ./scripts/init-android-release-signing.sh ``` Back up both reported files before uploading the first bundle. Losing this dedicated upload key is recoverable through Play App Signing, but keeping an offline backup avoids a reset. Do not copy either file into the repository. Configure these non-secret values in the deployment's ignored environment file, then produce the signed APK and Play bundle: ```dotenv WNH_BASE_URL=https://your-final-origin.example WNH_ANDROID_VERSION_CODE=1 WNH_ANDROID_VERSION_NAME=0.1.0 WNH_ANDROID_SIGNING_KEY_ALIAS=who-need-help-upload WNH_FIREBASE_APPLICATION_ID=1:123456789:android:example WNH_FIREBASE_API_KEY=the-public-firebase-android-client-key WNH_FIREBASE_PROJECT_ID=your-firebase-project WNH_FIREBASE_GCM_SENDER_ID=123456789 ``` The four Firebase Android client values are public application configuration, not the server credential. They must be either all present or all empty. Server delivery separately requires `FCM_PROJECT_ID` and exactly one service-account source in the Phoenix environment; never put that private JSON in the Android build. Google/Firebase setup is environment-specific as well: - dev/staging uses package `org.whoneedhelp.mobile.staging`, its stable staging signing certificate, the dev Web OAuth client, and the dev Firebase project; - production uses package `org.whoneedhelp.mobile`, the Play-distributed signing certificate, the production Web OAuth client, and the production Firebase project; - `GOOGLE_OAUTH_CLIENT_ID` and `GOOGLE_OAUTH_CLIENT_SECRET` stay in that checkout's single ignored `.env`; only the public client ID is returned at runtime to Credential Manager; - the server Web client ID is the audience requested by Credential Manager. Register the matching Android package/signing certificate in the same Google project before a real-device sign-in test. ```sh ./scripts/android-release-build.sh ``` The build passes the private files with Docker BuildKit secret mounts, runs release unit tests and lint, enables code/resource shrinking, signs both artifacts, verifies the APK and AAB signatures, and validates the AAB with the same `bundletool` used underneath Android Gradle Plugin and Google Play before exporting anything. It rejects a missing, HTTP, credentialed, query-bearing, or fragment-bearing release URL and rejects missing or partial signing configuration. Google Play requires an Android App Bundle for a new app. With Play App Signing, the locally held key signs the uploaded bundle and Google holds the separate app-signing key used for distributed APKs: - - - ## Public staging build The installable `staging` build type uses the explicit public HTTPS `WNH_BASE_URL`, disables cleartext traffic, and has its own `org.whoneedhelp.mobile.staging` application ID. Configure a missing local value from the existing `PHX_HOST`, `PHX_SCHEME`, and `PHX_URL_PORT`, then build: ```sh ./scripts/ensure-local-public-origin.sh ./scripts/android-staging-build.sh sha256sum android/dist-staging/who-need-help-staging.apk ``` This variant uses the dedicated stable staging key below `~/.config/who_need_help/android-staging/`. It is not the production upload identity and must not be published as a production release. The manifest accepts same-origin HTTPS deep links, while verified Android App Links require this staging certificate fingerprint in the dev deployment's `/.well-known/assetlinks.json`. With the temporary public origin reachable, run the API 37 emulator smoke test: ```sh ./scripts/android-staging-smoke.sh ``` The script installs the exported staging APK into a fresh project-scoped emulator container, loads the configured HTTPS home page, follows a same-origin `/safety` deep link, verifies that the package does not claim an external HTTPS origin, and retains UI dumps, screenshots, package metadata, and logcat diagnostics under ignored `output/android-staging-smoke/`. The one-run container and image are removed on success or failure. ## Reproducible Docker build From the repository root: ```sh ./scripts/android-build.sh sha256sum android/dist/who-need-help-debug.apk ``` The Docker build runs JVM unit tests, Android lint, `assembleDebug`, and `assembleDebugAndroidTest` before it exports the application APK and lint report. ## Automated device tests Run the default API 37 suite or the complete API 24/30/34/37 matrix from the repository root: ```sh ./scripts/android-instrumentation-test.sh ./scripts/android-matrix-test.sh ``` The command requires `/dev/kvm`. It generates ignored `output/runtime/android-test.env` once with a randomized `http://127.0.0.1:PORT` origin and mode `0600`; the application and its in-process fixture server both derive the origin from that file. It then builds both APKs, boots a fresh selected emulator container without external networking, injects emulator coordinates, and runs `AndroidJUnitRunner`. `WNH_ANDROID_TEST_API` selects one supported API, while `WNH_ANDROID_TEST_API_MATRIX` controls the matrix command. The tests cover the missing-location-permission boundary, the WebView-triggered Android permission dialog, same-origin deep-link routing across Activity recreation, foreground location upload after Home and Activity destruction, the persistent notification Stop action, a disconnected Stop request with visible retry state, and externally forced process death for the non-sticky tracking service. Results are stored by API under ignored `output/android-instrumentation/`. On failure, logcat, service state, and emulator logs are retained; the exact container and one-run image are removed in either outcome. ## Emulator verification The optional `emulator` target contains the API 37.0 Google APIs x86_64 system image. Manual verification against the local Compose application requires KVM and host networking. Pass the same `.env` value as a build argument, then expose the Compose proxy to Android with `adb reverse`: ```sh set -a . ./.env set +a docker build \ --build-arg "WNH_DEBUG_BASE_URL=$WNH_DEBUG_BASE_URL" \ --build-arg "WNH_TRACKING_MIN_TIME_MS=$WNH_TRACKING_MIN_TIME_MS" \ --build-arg "WNH_TRACKING_HTTP_TIMEOUT_MS=$WNH_TRACKING_HTTP_TIMEOUT_MS" \ --target emulator \ -t who-need-help-android:emulator \ android docker run --rm --name who-need-help-android-emulator \ --device /dev/kvm \ --network host \ who-need-help-android:emulator docker exec who-need-help-android-emulator adb reverse tcp:4010 tcp:4010 docker exec who-need-help-android-emulator adb install \ /opt/who-need-help/who-need-help-debug.apk ``` The application ID `org.whoneedhelp.mobile` is provisional until the publishing identity and store listing are chosen. Google documents Play package names as unique and permanent, so do not create the Play Console app or publish this identifier until that choice is explicit. Changing it after publication creates a different Android application.