Keyed

DJ BPM & Key Finder

Detect the key and BPM of any song playing around you, completely offline. Built for DJs mixing vinyl and digital.

Features

• Real-time detection — Instantly identifies BPM and musical key via your device's microphone
• Confidence scoring — See how accurate each reading is
• Fully offline — No internet required, no data leaves your device
• Cross-platform — Available on iOS and Android

Privacy

Keyed processes all audio locally on your device. No audio data, song information, or usage analytics are ever collected or transmitted. Your listening stays private.

Tech Stack

• Expo / React Native
• TypeScript
• react-native-unistyles for styling
• TanStack Query for state management
• Turborepo monorepo structure

Analysis Documentation

• docs/ANALYSIS.md - Current end-to-end native analysis architecture (BPM + key)
• docs/BEATNET.md - BPM pipeline internals and model notes
• docs/KEY_DETECTION.md - Key-analysis pipeline internals and API

Development

Prerequisites

• Bun v1.2.16+
• iOS Simulator / Android Emulator or physical device
• Xcode (for iOS) / Android Studio (for Android)

Setup

# Clone the repository
git clone https://github.com/jmcmullen/keyed.git
cd keyed

# Install dependencies
bun install

# Start the development server
bun run dev:native

Scripts

Command	Description
bun run dev:native	Start Expo development server
bun run build	Build all packages
bun run check	Run linting and formatting
bun run check-types	TypeScript type checking

Project Structure

keyed/
├── apps/
│   └── native/       # React Native mobile app
├── packages/
│   └── config/       # Shared TypeScript configuration
└── ...

Contributing

Contributions are welcome. Please open an issue first to discuss what you'd like to change.

1. Fork the repository
2. Create your branch (git checkout -b feature/your-feature)
3. Commit your changes
4. Push to the branch
5. Open a pull request

License

MIT