FitnessCoachAI

iOS fitness coach app with OpenAI Realtime API voice conversation.

Features

• ✅ Real-time voice conversation with AI fitness coach
• ✅ AudioUnit with VoiceProcessingIO for echo cancellation
• ✅ Server-side VAD (Voice Activity Detection)
• ✅ Natural interruption support (barge-in)
• ✅ Animated ring UI (glistens when listening, pulses when speaking)
• ✅ Auto-start recording when ready

Setup

1. Clone the repository

git clone https://github.com/nidzae/FitnessCoachVoice-iOS.git
cd FitnessCoachVoice-iOS/FitnessCoachAI

2. Configure API Key

# Copy the template config file
cp Config.template.xcconfig Config.xcconfig

# Edit Config.xcconfig and add your OpenAI API key
# Replace YOUR_OPENAI_API_KEY_HERE with your actual key

3. Open in Xcode

open FitnessCoachAI.xcodeproj

4. Run the app

• Select your target device/simulator
• Press ⌘R to build and run

Architecture

FitnessCoachAI/
├── Models/
│   └── VoiceAgentState.swift       # App state model
├── Services/
│   ├── AudioManager.swift          # AudioUnit recording + AVAudioEngine playback
│   └── OpenAIVoiceService.swift    # WebSocket connection to OpenAI Realtime API
├── ViewModels/
│   └── VoiceCoachViewModel.swift   # Business logic and state management
└── Views/
    ├── HomeView.swift              # Main screen
    ├── VoiceRingView.swift         # Animated ring component
    └── VoiceAvatarView.swift       # (Legacy, replaced by VoiceRingView)

Key Technologies

• AudioUnit with VoiceProcessingIO: Hardware-level echo cancellation
• OpenAI Realtime API: GPT-based voice conversation
• Server VAD: Automatic speech detection and turn management
• SwiftUI: Modern UI with custom animations

Configuration Files

• Config.xcconfig - Your actual API keys (ignored by git)
• Config.template.xcconfig - Template for new developers (committed to git)
• .gitignore - Ensures sensitive files aren't committed

Notes

• Working voice conversation with realtime only
• No video or camera implementation
• Mic auto-starts when session is ready
• Echo cancellation prevents the agent from hearing itself

License

Private project