crowncrate-android

The Android companion app for the CrownOS phone bridge — clipboard sync, notification sync, call bridging, OTP sync and file sharing between your phone and a CrownOS desktop.

Status: Skeleton. This is currently an unmodified Android Studio "Compose + Navigation Suite" template with the app renamed. It has no networking code and no network permission, so it cannot talk to the desktop at all.

Toolchain

AGP	8.13.1
Kotlin	2.0.21
compileSdk / targetSdk	36
minSdk	29
JVM target	11
Compose BOM	2024.09.00
UI	material3 + material3-adaptive-navigation-suite
Application ID	com.crownos.crate

Requires JDK 17 or newer — AGP 8.13.1 refuses to run Gradle on anything older. The jvmTarget = "11" above is the output bytecode level, not the JDK you build with. The Gradle wrapper is committed.

Android SDK setup

This is the only thing between a clean machine and a green build, and nothing else documents it. Install the SDK, then point Gradle at it:

export ANDROID_HOME="$HOME/Android/Sdk"
sdkmanager --install "platforms;android-36" "build-tools;36.0.0" "platform-tools"
yes | sdkmanager --licenses

ANDROID_HOME in the environment is the portable option. Alternatively write the path into an untracked local.properties:

echo "sdk.dir=$HOME/Android/Sdk" > local.properties

Without one of the two, the build fails with "SDK location not found".

Build

./gradlew assembleDebug
./gradlew installDebug     # to a connected device or emulator
./gradlew test

There is no ktlint plugin configured, so ./gradlew ktlintCheck and ktlintFormat do not exist and will fail with "task not found". Follow the official Kotlin coding conventions by hand. Adding the plugin would be a welcome chore PR.

What it needs to become

The desktop side already defines the contract. To make the two halves talk:

1. Permissions. The manifest currently has zero <uses-permission> entries. At minimum INTERNET; then BIND_NOTIFICATION_LISTENER_SERVICE for notification sync, READ_PHONE_STATE / ANSWER_PHONE_CALLS for the call bridge, and clipboard access.

2. A TCP client to <desktop>:5252, holding the connection open for the session.

3. CBOR framing of the message shape the daemon expects:

Message { client: Ipv4Addr, method: Actions, body: Map<String, String> }
Actions: CLIPBOARD | MEDIA | OPEN | OTPSYNC | MONITOR | VOLUME | SHUTDOWN

4. Discovery. The desktop binds UDP :5253 for this, but its discovery function is a stub — so the protocol is undefined on both sides and needs designing.

5. Pairing and encryption. Neither side has any. The desktop currently accepts unauthenticated commands including remote shutdown, which is not acceptable to ship.

Protocol detail: IPC and protocols. Server: crowncrate-linux.

Known limitations

• AndroidManifest.xml declares zero <uses-permission> entries — not even INTERNET. The app therefore cannot open a socket, which is the one thing a phone bridge exists to do. This is the first thing to fix.
• There is no networking code at all, only the Compose template's screens.
• No pairing or encryption, on either side of the bridge.
• .gitignore is the stock Android Studio list, but .idea/ is only partially ignored and eight .idea/*.xml files are committed. The Gradle wrapper jar is conventional; the IDE files are not.

Contributing

See the organization-wide contribution guide. Default branch here is main.

License

Licensed under the MIT License.