SendSpin Player & Music Assistant Client for Android

A native Android client for SendSpin

Features

Synchronized Playback

• Precision-synced audio across unlimited rooms
• Background audio with lock screen and notification controls
• Android Auto integration
• Android TV support
• Hardware volume buttons with bidirectional sync
• Skip, pause, seek, and group switching from any device
• Adjustable sync offset for speaker delay compensation

Music Assistant Integration

• Browse your full music library -- albums, artists, tracks, playlists, and radio
• Full-text search across your entire collection
• Album and artist detail screens with cover art
• Create and manage playlists, add or remove tracks
• Queue management -- view upcoming tracks, reorder, remove, clear
• Play Next and Add to Queue from any browse or search screen
• Shuffle and repeat mode controls

Audio Quality

• Opus -- efficient compressed streaming, great for cellular
• FLAC -- lossless quality for critical listening on WiFi
• PCM -- uncompressed raw audio
• Network-aware codec selection -- automatically choose the best format per connection type
• Separate WiFi and cellular codec preferences
• 48 kHz stereo output

Interface

• Material You dynamic colors -- matches your wallpaper on Android 12+
• Full dark and light theme support
• Bottom navigation with Home, Library, Search, and Playlists tabs
• Mini player bar with configurable position (top or bottom)
• Full-screen now playing view with album art and playback controls
• Queue bottom sheet accessible from the now playing screen
• Full-screen immersive mode
• Keep screen on while playing
• Portrait and landscape support

Connectivity

• Automatic server discovery via mDNS/Zeroconf on local networks
• Manual server entry for direct connections
• Remote access via Music Assistant Remote ID (WebRTC)
• QR code scanner for quick Remote ID input
• HTTP proxy support for routed connections
• Automatic reconnection on network changes
• Works on WiFi, Ethernet, and cellular networks

Server Management

• Multi-server support with saved server list
• Add Server wizard with guided setup (discover, login, test, save)
• Music Assistant authentication with token-based login
• Per-server connection configuration
• Server status monitoring

Settings

• Custom player name
• Display preferences (full-screen mode, keep screen on, mini-player position)
• Audio sync offset tuning
• Preferred codec selection (per WiFi and cellular)
• Low memory mode for older devices
• Debug logging with log export
• Stats for Nerds -- real-time sync diagnostics

Getting Started

1. Install -- Download the latest APK from Releases
2. Open -- The app searches for SendSpin servers on your network
3. Tap -- Select your server and you're listening

For development and testing guides, see the Wiki.

Connecting to a Server

• Local network: Servers are discovered automatically via mDNS
• Manual entry: Tap "Enter server manually" and type your server address (e.g., 192.168.1.100:7080)
• Remote access: Enter a Music Assistant Remote ID or scan a QR code to connect from anywhere
• Proxy: Configure an HTTP proxy for routed connections

Requirements

• Android 8.0 (Oreo) or higher
• A SendSpin server on your network (or a Remote ID for remote access)

Installing the APK

Since SendSpin Player isn't on the Play Store, you'll need to allow installation from your browser:

1. Download the APK from Releases
2. Open the downloaded file
3. When prompted, tap Settings -> enable Allow from this source
4. Go back and tap Install

Architecture

SendSpin Player is built with native Kotlin and Jetpack Compose, using a hybrid architecture:

• Jetpack Compose for library browsing, search, playlists, detail screens, queue, and settings
• XML layouts with ViewBinding for the main activity shell, now playing screen, and server management
• Fragments for navigation within the bottom navigation tabs
• ViewModels for state management across configuration changes
• Coroutines for async operations and WebSocket communication
• Media3 MediaSession for system integration, notifications, and Android Auto

The SendSpin Protocol

SendSpin Player speaks the SendSpin Protocol -- a WebSocket-based streaming protocol designed for real-time synchronized audio. The server timestamps every audio chunk and each client uses precision clock synchronization to play them at exactly the right moment. The result: every speaker in your home plays the same beat at the same time.

License

MIT -- see LICENSE for the full text.

Third-Party Acknowledgments

SendSpin Player uses the following open-source libraries:

| Library | License | Copyright | |---------|---------|-----------| | AndroidX (Core, AppCompat, Lifecycle, Media3, Compose, CameraX, Palette, Preference, Fragment, ViewPager2, SwipeRefreshLayout, ConstraintLayout) | Apache 2.0 | The Android Open Source Project | | Material Components for Android | Apache 2.0 | The Android Open Source Project | | Kotlin & Kotlinx Coroutines | Apache 2.0 | JetBrains s.r.o. and contributors | | OkHttp | Apache 2.0 | Square, Inc. | | Coil | Apache 2.0 | Coil Contributors | | Stream WebRTC Android | Apache 2.0 | Stream.io Inc. | | Java-WebSocket | MIT | Nathan Rajlich | | QR code scanning uses zxing-cpp | Apache 2.0 | |