FidoNext Messenger

An Android messenger application built with Kotlin and Jetpack Compose, using the libcabi_rust_libp2p native library from fidonext-core (pre-built binaries only; no Rust or native build in this repo).

Features

• 🎨 Modern UI with Jetpack Compose
• 🔒 Message encryption using native libp2p library
• 💬 Real-time chat interface
• 📱 Material Design 3
• ⚡ High-performance message processing

Architecture

Android (Kotlin)

• UI Layer: Jetpack Compose with Material 3
• ViewModel: MVVM architecture with StateFlow
• JNI Bridge: Native interface to libcabi_rust_libp2p (pre-built)

Native library (libcabi_rust_libp2p)

• Pre-built binaries from fidonext-core releases
• Downloaded at build time; JNI in app/src/main/cpp/ links against the .so

Prerequisites

• Android Studio (latest version)
• Android SDK 24+
• Android NDK (for building the JNI wrapper; installed via SDK Manager)

Quick Start

1. Optional: Add a relay list at app/src/main/assets/bootstrap_nodes.txt.
2. Build (downloads libp2p binary from fidonext-core if needed, then builds the app):

   ./scripts/build.sh

   Or with Gradle only:

   ./gradlew assembleDebug

   The first build will run scripts/download_libcabi_rust_libp2p.sh to fetch the pre-built libcabi_rust_libp2p for arm64-v8a.
3. Run: e.g. ./scripts/run.sh or install the APK on a device/emulator.

Note: Pre-built library is arm64-v8a only (real devices). x86/x86_64 emulators are not supported unless fidonext-core adds those binaries to releases.

Setup

1. Android Studio / SDK: Install Android Studio and NDK (SDK Manager → SDK Tools → NDK).
2. local.properties (optional, if not auto-detected):

   sdk.dir=/path/to/Android/sdk

3. Build: Run ./scripts/build.sh or ./gradlew assembleDebug. The first run will download the native library from GitHub releases.

Project Structure

fidonext_android/
├── app/
│   ├── src/main/
│   │   ├── java/com/fidonext/messenger/
│   │   │   ├── MainActivity.kt           # Main UI
│   │   │   ├── data/
│   │   │   │   └── Message.kt            # Data models
│   │   │   ├── rust/                     # Kotlin package: JNI bindings to libp2p
│   │   │   │   └── RustNative.kt
│   │   │   ├── ui/theme/                 # Compose theme
│   │   │   └── viewmodel/
│   │   │       └── ChatViewModel.kt      # Business logic
│   │   ├── jniLibs/                      # Pre-built libcabi_rust_libp2p (downloaded)
│   │   └── AndroidManifest.xml
│   └── build.gradle.kts
├── scripts/
│   ├── build.sh                          # Download libp2p + Gradle build
│   └── download_libcabi_rust_libp2p.sh        # Fetch binary from fidonext-core releases
└── build.gradle.kts

Native library (libcabi_rust_libp2p)

Pre-built binaries are downloaded from fidonext-core releases. To use a different version, set FIDONEXT_CORE_RELEASE when running the download script (e.g. FIDONEXT_CORE_RELEASE=v0.0.3 ./scripts/download_libcabi_rust_libp2p.sh).

Development

Running the app:

./gradlew installDebug

Testing:

Use Android instrumented/unit tests as usual.

Building release APK:

./gradlew assembleRelease

Security Note

⚠️ The current encryption implementation uses a simple XOR cipher for demonstration purposes. For production use, implement proper encryption using libraries like:

• AES-GCM (already included in dependencies)
• ChaCha20-Poly1305
• Or use established protocols like Signal Protocol

License

MIT License

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.