CIS553 Fall 2025 - Software Engineering Project

Sell anything instantly by taking a photo. Our AI handles pricing, multi-platform posting, buyer communication, and pickup scheduling automatically.

Sold revolutionizes online selling by automating the entire process:

1. 📸 Take a photo of your item
2. 🤖 AI analyzes and suggests optimal pricing
3. 🚀 One-click post to Facebook Marketplace, Craigslist, OfferUp, 5miles
4. 💬 AI agent chats with buyers to negotiate and schedule pickup
5. 💰 Get paid via Venmo/Zelle

📋 Complete Documentation Index - All documentation organized

Quick Links:

• Project Proposal - Main submission (Due 10/3)
• Current Status - What's built vs. planned
• Start App Guide - How to run locally
• Facebook API Guide - Complete integration guide

Planning:

• Team Tasks - Sprint planning & assignments
• Tech Stack - Architecture & technology decisions
• Requirements Mapping - CIS553 compliance

sold/
├── backend/          # Express.js REST API (TypeScript)
├── mobile/           # React Native app (iOS & Android)
├── shared/           # Shared TypeScript types & validators
├── docs/             # Documentation
└── .github/          # CI/CD workflows

Backend

• Node.js 20 + Express.js + TypeScript
• PostgreSQL 15 (Prisma ORM)
• Redis (Bull queue for jobs)
• AWS S3 (image storage)

Mobile

• React Native 0.72+
• TypeScript
• Zustand (state management)
• React Navigation

AI/ML Services (Third-party APIs)

• OpenAI Vision API (image analysis)
• OpenAI GPT-4 (conversational agent)

Integrations

• Google/Facebook OAuth
• Stripe (payments)
• Google Calendar
• Marketplace APIs (Facebook, Craigslist, etc.)

We provide automated setup scripts for easy onboarding:

# Clone the repository
git clone <repository-url>
cd sold

# Run the setup script
chmod +x setup-mac.sh
./setup-mac.sh

The script will:

• ✅ Install Homebrew (if needed)
• ✅ Install Node.js 20, pnpm, PostgreSQL, Redis, Watchman
• ✅ Install project dependencies
• ✅ Set up environment files
• ✅ Create database and run migrations
• ✅ Optionally start iOS simulator or web browser

# Clone the repository
git clone <repository-url>
cd sold

# Run the setup script (in Git Bash, WSL, or Linux terminal)
chmod +x setup-pc.sh
./setup-pc.sh

The script will:

• ✅ Check for Node.js 20+ and pnpm
• ✅ Guide PostgreSQL and Redis installation
• ✅ Install project dependencies
• ✅ Set up environment files
• ✅ Create database and run migrations
• ✅ Choose between Android emulator or web browser

Requirements:

• macOS 12+ (Monterey or later)
• Xcode 14+ (Download from App Store)
• CocoaPods (sudo gem install cocoapods)
• Watchman (brew install watchman)

Setup:

# Accept Xcode license
sudo xcodebuild -license accept

# Install CocoaPods dependencies (if needed)
cd mobile/ios && pod install && cd ../..

# Start iOS simulator
pnpm mobile:ios

Requirements:

• Android Studio (Download)
• Java JDK 11+
• Android SDK (API level 33+)

Setup:

1. Install Android Studio
2. Open Android Studio > Settings > Android SDK
3. Install SDK Platform 33 and SDK Build-Tools
4. Create a virtual device (AVD) via AVD Manager
5. Set environment variables:

   # Add to ~/.bashrc, ~/.zshrc, or ~/.bash_profile
   export ANDROID_HOME=$HOME/Library/Android/sdk  # macOS
   export ANDROID_HOME=$HOME/Android/Sdk          # Linux/WSL
   export PATH=$PATH:$ANDROID_HOME/emulator
   export PATH=$PATH:$ANDROID_HOME/platform-tools

6. Start emulator and run:

   pnpm mobile:android

Requirements:

• Modern web browser (Chrome, Firefox, Safari, Edge)
• Node.js 20+

Setup:

# Just run the web server
pnpm mobile:web

Your default browser will open automatically at http://localhost:19006

After setup, edit backend/.env with your API keys:

# Database
DATABASE_URL="postgresql://user:password@localhost:5432/sold_dev"

# Redis (optional for development)
REDIS_URL="redis://localhost:6379"

# JWT
JWT_SECRET="your-secret-key-here"
JWT_REFRESH_SECRET="your-refresh-secret-here"

# OpenAI (required for AI features)
OPENAI_API_KEY="sk-..."

# AWS S3 (required for image uploads)
AWS_ACCESS_KEY_ID="..."
AWS_SECRET_ACCESS_KEY="..."
AWS_S3_BUCKET="sold-images-dev"
AWS_REGION="us-east-1"

# Google OAuth (optional)
GOOGLE_CLIENT_ID="..."
GOOGLE_CLIENT_SECRET="..."

# Facebook OAuth (optional)
FACEBOOK_APP_ID="..."
FACEBOOK_APP_SECRET="..."

# Stripe (optional)
STRIPE_SECRET_KEY="sk_test_..."
STRIPE_PUBLISHABLE_KEY="pk_test_..."

"Command not found: pnpm"

npm install -g pnpm

PostgreSQL connection error

# macOS
brew services start postgresql@15

# Linux/WSL
sudo service postgresql start

# Windows
# Start PostgreSQL via Services or pgAdmin

"ANDROID_HOME not set"

# Add to your shell profile
export ANDROID_HOME=$HOME/Library/Android/sdk  # macOS
export ANDROID_HOME=$HOME/Android/Sdk          # Linux

Port already in use

# Backend (default: 3000)
lsof -ti:3000 | xargs kill -9

# Expo (default: 19000)
lsof -ti:19000 | xargs kill -9

iOS build fails

cd mobile/ios
pod install
cd ../..

"Watchman crawl failed" (macOS)

watchman watch-del-all

# Run all tests
pnpm test

# Run backend tests with coverage
pnpm backend:test

# Run mobile tests
pnpm mobile:test

# Run linter
pnpm lint

# Format code
pnpm format

• src/routes/ - API endpoints
• src/controllers/ - Business logic
• src/services/ - External integrations (OpenAI, Stripe, etc.)
• src/middleware/ - Auth, validation, error handling
• prisma/ - Database schema & migrations
• tests/ - Unit & integration tests

• src/screens/ - App screens (Auth, Camera, Listings, etc.)
• src/components/ - Reusable UI components
• src/navigation/ - React Navigation setup
• src/store/ - Zustand state management
• src/services/ - API client

• src/types/ - TypeScript interfaces
• src/constants/ - Shared constants
• src/validators/ - Zod validation schemas

1. Create feature branch: git checkout -b feature/task-name
2. Write tests first (TDD approach)
3. Implement feature
4. Run tests: pnpm test
5. Commit: git commit -m "feat: add feature description"
6. Push & create PR: GitHub Actions runs CI
7. Code review (1 approval required)
8. Merge to main (auto-deploy to staging)

14-week development schedule (7 sprints)

6-Person Development Team

• Backend Dev 1: Authentication, User Management, Images
• Backend Dev 2: Platform Integrations, AI Services, Payments
• Mobile Dev 1: Auth, Camera, Item Creation
• Mobile Dev 2: Listings, Conversations, Notifications
• DevOps Engineer: Infrastructure, CI/CD, Deployment
• AI Engineer: Price Detection, Chat Agent, NLP

• Jira: Sprint planning, task tracking
• GitHub: Source control, PR reviews
• Confluence: Documentation (optional)

• Bcrypt password hashing (12 rounds)
• JWT tokens (15min access, 7day refresh)
• HTTPS only
• Input validation (Zod schemas)
• SQL injection prevention (Prisma)
• File upload validation
• Rate limiting

Revenue Models (A/B testing):

• Per-post: $0.50/post
• Subscription: $6/month unlimited
• Transaction fee: 5% of sale

This project is part of CIS553 coursework at UMD.

1. Follow the coding standards (ESLint + Prettier)
2. Write tests for new features
3. Update documentation
4. Create meaningful commit messages (Conventional Commits)
5. Request code review before merging

• Facebook Marketplace API research (may need manual posting)
• Legal review for platform automation
• Instructor approval for OpenAI API usage
• Team size confirmation (6 vs 5 members)

Project Lead: Broderick Higby Course: CIS553 Fall 2025 Institution: University of Michigan Dearborn

Phase 1 Status: ✅ Complete

• Requirements reviewed
• Tech stack defined
• Database schema designed
• Monorepo structure created
• Testing framework configured
• Backend auth implementation (next)