ResaleHub — Backend API

The backend service for ResaleHub, a multi-marketplace inventory management system. Built with FastAPI and PostgreSQL, it handles inventory synchronization, image processing, and integrations with platforms like eBay and Poshmark.

🛠 Tech Stack

• Framework: FastAPI (Python 3.10+)
• Database: PostgreSQL (Production) / SQLite (Local Dev fallback)
• ORM: SQLAlchemy
• Automation: Playwright (for Poshmark automation/scraping)
• Deployment: Render.com

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📂 Project Structure

.
├── app/
│   ├── core/           # Config, security, and constants
│   ├── routers/        # API endpoints (Inventory, Auth, Marketplaces)
│   ├── services/       # Business logic (eBay API, Image processing)
│   ├── models.py       # SQLAlchemy database models
│   ├── schemas.py      # Pydantic data schemas
│   ├── database.py     # Database connection logic
│   └── main.py         # App entry point
├── media/              # Local storage for user uploads (gitignored content)
├── requirements.txt    # Python dependencies
└── README.md           # Project documentation

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🚀 Local Development Setup

1. Prerequisites

• Python 3.10 or higher
• PostgreSQL (Optional for local dev, can use SQLite)

2. Create Virtual Environment

# macOS/Linux
python -m venv .venv
source .venv/bin/activate

# Windows
python -m venv .venv
.venv\Scripts\activate

3. Install Dependencies

pip install --upgrade pip
pip install -r requirements.txt

4. Configure Environment

Create a .env file in the root directory. Note: If no .env is provided, the app defaults to using a local SQLite database (sql_app.db).

5. Run the Server

Start the server with hot-reload enabled:

uvicorn app.main:app --reload --host 127.0.0.1 --port 8000

• API Docs: http://127.0.0.1:8000/docs
• ReDoc: http://127.0.0.1:8000/redoc

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☁️ Deployment (Render.com)

This repository is optimized for deployment on Render.

1. Database Setup (PostgreSQL)

1. Create a New PostgreSQL database on Render.
2. Copy the Internal Connection String.

2. Service Configuration

Create a New Web Service connected to this repo.

Environment Variables:

Variable	Value	Description
DATABASE_URL	postgres://...	Paste your Render Postgres internal URL here.
SECRET_KEY	your-secret-key	Random string for security/hashing.
PLAYWRIGHT_BROWSERS_PATH	0	Forces Playwright to use installed system browsers.

Build & Start Commands: Because this project uses Playwright, we must install the browsers during the build step.

• Build Command:

  pip install -r requirements.txt && python -m playwright install chromium
  

• Start Command:

  uvicorn app.main:app --host 0.0.0.0 --port $PORT
  

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⚠️ Known Issues & Maintenance

1. Database Persistence

• Production: Uses PostgreSQL. The database.py file automatically fixes the Render connection string (replacing postgres:// with postgresql://).
• Tables: Currently, tables are auto-created in main.py via Base.metadata.create_all().
• Recommendation: Switch to Alembic for managing schema migrations in the future.

2. Circular Imports

There is a known circular import between app/services/ebay_client.py and app/routers/marketplaces.py regarding EBAY_SCOPES.

• Fix: Move shared constants to app/core/constants.py.

3. Async/Sync Blocking

Some async endpoints currently call synchronous SQLAlchemy methods (db.query), which may block the event loop under heavy load.

• Fix: Future refactoring should implement run_in_threadpool or switch to asyncpg.

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📄 License

Private Repository. All rights reserved.