# System Patterns

## Architecture Overview
1. Screenshot Capture Module
2. Board Position Analysis Engine
3. Visual Overlay System
4. Stockfish Integration

## Key Technical Decisions
1. MacOS Silicon (ARM64) native implementation
2. Firefox browser integration
3. Low-latency overlay system
4. In-memory Stockfish engine

## Data Flow
1. Screenshot → Board Position Detection → FEN Conversion → Stockfish Analysis → Visual Overlay