RetroDiffusion iOS App

A SwiftUI iOS app for generating and pixelating images using the RetroDiffusion API with modern Swift 6.2 concurrency and an actor-based architecture.

Features

• Pixelate Tab: Select images from your photo library and convert them to pixel art using the rd_pro__pixelate style
  • Real-time cost preview before pixelation
  • Save pixelated images to your photo library
• Generate Tab: Generate pixel art images from text prompts using various RetroDiffusion model styles
  • Debounced cost preview (updates after you stop typing)
  • Model selection with 30+ styles (RD_PRO, RD_FAST, RD_PLUS)
  • Customizable image dimensions
  • Save generated images to your photo library
• Library: Persist generated/pixelated images in a SQLite-backed store with paging for large collections
  • Async loading off the main thread via actors
  • Lazy loading/pagination in the grid for smoother scrolling with large libraries

Setup

Prerequisites

• iOS 26.1 or later
• Xcode 26.1 or later
• RetroDiffusion API key

API Key Configuration

1. Create a Config.plist file in the RetroDiffusionApp directory if it doesn't exist
2. Add the following structure to the plist file:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>API_KEY</key>
    <string>YOUR_API_KEY_HERE</string>
</dict>
</plist>

3. Replace YOUR_API_KEY_HERE with your actual RetroDiffusion API key
4. Get your API key from RetroDiffusion Dev Tools

Important: The Config.plist file is already added to .gitignore to prevent committing your API key to version control.

Architecture

• Swift 6.2 Concurrency: Heavy work runs on dedicated actors where stateful isolation is needed
• Services:
  • Networking actor for API calls, wrapped by a NetworkClient (@MainActor @Observable) for SwiftUI
  • ImageUtils and ImageSaver stateless utilities used from background tasks to keep CPU and Photos writes off the main thread without cross-actor hops
  • LibraryStore actor backed by SQLite for scalable persistence; LibraryClient (@MainActor @Observable) handles paging and caching for the UI
• SwiftUI + @Observable: Environment-injected clients; UI state remains local to views where possible
• Component-Based UI: Reusable SwiftUI components for generation, pixelation, library, and shared controls

API Documentation

For detailed API documentation, visit:

• RetroDiffusion API Examples

Project Structure

RetroDiffusionApp/
├── RetroDiffusionAppApp.swift    # App entry point with service initialization
├── Config.plist                  # API key configuration (gitignored)
├── Assets.xcassets/              # App assets
│
├── actors/                       # Actor-backed services (concurrency-safe)
│   ├── Networking.swift          # Networking actor
│   └── LibraryStore.swift        # SQLite-backed library actor
│
├── utils/                        # Utilities
│   ├── ImageUtils.swift          # Image resizing/base64 utilities
│   └── ImageSaver.swift          # Photo library saver utilities
│
├── library/                      # Library UI + client
│   ├── LibraryClient.swift       # @MainActor wrapper for paging/caching over LibraryStore
│   ├── LibraryView.swift         # Library grid with paging
│   ├── LibraryThumbnailView.swift# Async thumbnail loading
│   └── LibraryDetailView.swift   # Full-size view/share
│
├── networking/                   # Networking client layer
│   └── NetworkClient.swift       # @MainActor wrapper over Networking actor
│
├── components/                   # Shared UI components
│   └── …                         # Pixelate/Generate tabs, controls, etc.
│
├── models/                       # Data models
│   └── Models.swift
│
└── utils/                        # Misc constants/config
    └── Constants.swift

Usage

Pixelate Images

1. Open the "Pixelate" tab
2. Tap "Choose Photo" to select an image from your photo library
3. View the cost preview (automatically calculated)
4. Tap "Pixelate Image" to convert it to pixel art
5. View the original and pixelated images side-by-side
6. Tap "Save to Photos" to save the pixelated image to your photo library

Generate Images

1. Open the "Generate" tab
2. Select a model style from the picker (30+ styles available)
3. Enter a text prompt describing the image you want to generate
4. Optionally adjust the width and height (default: 256x256)
5. View the cost preview (updates automatically after you stop typing)
6. Tap "Generate Image" to create pixel art
7. View the generated image
8. Tap "Save to Photos" to save the generated image to your photo library

Requirements

• iOS 26.1+
• Swift 5.0+
• RetroDiffusion API account with credits