Fab Construction — Inventory Management System

A full-stack, production-quality Inventory Management System built for Fab Construction. Tracks products, locations, suppliers, stock movements, and work processes.

Case study: denxhinjo-labs.vercel.app/projects/fab-inventory-system

Tech Stack

Layer	Technology
Frontend	React 18 + TypeScript + Tailwind CSS + Vite
Backend	FastAPI (Python 3.12)
Database	PostgreSQL 16
ORM	SQLAlchemy 2 + Alembic
Auth	JWT (python-jose) + bcrypt
File Upload	Local media storage (S3-ready structure)
Charts	Recharts
State	TanStack Query (React Query)

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Features

• Role-based auth (Admin / User) with JWT tokens
• Inventory CRUD — products with images, SKU, category, location, supplier, stock levels
• Stock movement tracking — Stock In / Stock Out / Adjustment with full history
• Work process management — task statuses, priorities, assignments, timelines
• Multi-location support — scalable location model with manager/contact info
• Supplier management — track vendors per product
• Dashboard — live stats, low-stock alerts, recent activity
• Reports — bar charts, pie charts, date-filtered movement history
• User management (Admin only) — create, update, deactivate users
• Responsive design — mobile, tablet, and desktop

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Quick Start (Local Development)

Prerequisites

• Python 3.12+
• Node.js 20+
• PostgreSQL 16 running locally

1. Database

psql -U postgres -c "CREATE DATABASE fab_construction_ims;"

2. Backend

cd backend

# Copy env and configure
cp .env.example .env
# Edit .env if needed (DATABASE_URL, SECRET_KEY)

# Create virtual environment and install
python -m venv .venv
source .venv/bin/activate        # Windows: .venv\Scripts\activate
pip install -r requirements.txt

# Run database migrations
alembic upgrade head

# Seed demo data
python seed_data.py

# Start the API server
uvicorn app.main:app --reload --host 0.0.0.0 --port 8000

API docs: http://localhost:8000/api/docs

3. Frontend

cd frontend
npm install
npm run dev

App: http://localhost:5173

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Docker (Full Stack)

# Start everything with Docker Compose
docker-compose up --build

# App at:   http://localhost:3000
# API at:   http://localhost:8000/api/docs

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Demo Accounts

Role	Email	Password
Admin	admin@fabconstruction.com	admin
User	john.smith@fabconstruction.com	User@123
User	sarah.jones@fabconstruction.com	User@123
User	mike.wilson@fabconstruction.com	User@123

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Project Structure

IMS_Clean/
├── backend/
│   ├── app/
│   │   ├── main.py              # FastAPI entry point
│   │   ├── config.py            # Settings (pydantic-settings)
│   │   ├── database.py          # SQLAlchemy engine + session
│   │   ├── dependencies.py      # Auth dependency injection
│   │   ├── models/              # SQLAlchemy ORM models
│   │   ├── schemas/             # Pydantic request/response schemas
│   │   └── routers/             # API route handlers
│   ├── alembic/                 # Database migrations
│   ├── media/                   # Uploaded product images
│   ├── seed_data.py             # Demo data seeder
│   ├── requirements.txt
│   ├── Dockerfile
│   └── .env.example
│
├── frontend/
│   ├── src/
│   │   ├── App.tsx              # Routes + AuthProvider wrapper
│   │   ├── context/             # AuthContext (JWT + user state)
│   │   ├── services/api.ts      # Axios API client + interceptors
│   │   ├── types/index.ts       # TypeScript interfaces
│   │   ├── components/
│   │   │   ├── layout/          # Sidebar, Header, Layout
│   │   │   └── ui/              # Badge, Modal, Spinner, EmptyState...
│   │   └── pages/
│   │       ├── Login.tsx
│   │       ├── Dashboard.tsx
│   │       ├── Inventory/       # List, AddEdit, Detail
│   │       ├── Locations/
│   │       ├── WorkProcesses/
│   │       ├── Users/
│   │       └── Reports/
│   ├── Dockerfile
│   ├── nginx.conf
│   └── package.json
│
├── docker-compose.yml
└── README.md

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API Endpoints

Method	Path	Description
POST	/api/auth/login	Login (returns JWT)
GET	/api/auth/me	Current user
GET	/api/products	List products (paginated+filter)
POST	/api/products	Create product (multipart)
GET	/api/products/{id}	Get product detail
PUT	/api/products/{id}	Update product
DELETE	/api/products/{id}	Delete product (admin only)
GET	/api/categories	List categories
GET	/api/locations	List locations
GET	/api/suppliers	List suppliers
GET	/api/stock-movements	List movements (paginated)
POST	/api/stock-movements	Record stock movement
GET	/api/work-processes	List work processes
POST	/api/work-processes	Create work process
PUT	/api/work-processes/{id}	Update work process
GET	/api/users	List users (admin only)
POST	/api/users	Create user (admin only)
GET	/api/dashboard/stats	Dashboard statistics

Full interactive docs: http://localhost:8000/api/docs

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Environment Variables

Copy backend/.env.example to backend/.env and configure:

DATABASE_URL=postgresql://postgres:password@localhost:5432/fab_construction_ims
SECRET_KEY=your-super-secret-key-min-32-chars
ALGORITHM=HS256
ACCESS_TOKEN_EXPIRE_MINUTES=60
MEDIA_DIR=media
ALLOWED_ORIGINS=http://localhost:5173

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Database Migrations

# Create a new migration after changing models
cd backend
alembic revision --autogenerate -m "describe your change"

# Apply all migrations
alembic upgrade head

# Roll back one migration
alembic downgrade -1

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Future Enhancements

• S3/Supabase Storage for product images
• Email notifications for low stock
• PDF/CSV export for reports
• Mobile PWA support
• Barcode/QR scanning
• Multi-currency pricing