Hybrid-app

Hybrid App

Stack Project

Hybrid App

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Overview

Hybrid App is a full-stack web application that combines FastAPI and Flask in a single process. FastAPI handles the REST API layer while Flask + Jinja2 powers the server-rendered frontend. Both frameworks coexist thanks to a2wsgi, which mounts the Flask WSGI app onto the FastAPI instance.

Architecture

FastAPI (root app)
├── /api/items   → REST API (FastAPI + SQLAlchemy)
└── /            → Web UI (Flask + Jinja2 via WSGI middleware)

Tech Stack

Layer	Technology
API	FastAPI, Pydantic, fastapi-pagination
Web UI	Flask, Jinja2
Database	SQLAlchemy (SQLite by default)
Bridge	a2wsgi (WSGI ↔ ASGI)
Server	Uvicorn

Features

• REST API (/api/items) with full CRUD, pagination, and filtering by name and price range
• Server-rendered pages served by Flask at / and /about
• Auto-seeded database with sample items on first startup
• Input validation via Pydantic models

Getting Started

Install dependencies

pip install -r requirements.txt

Run the app

python run.py

The app will be available at http://localhost:8000.

Endpoint	Description
GET /	Flask home page
GET /about	Flask about page
GET /api/items	List items (paginated)
POST /api/items	Create a new item
GET /api/items/{id}	Get item by ID
PUT /api/items/{id}	Update an item
DELETE /api/items/{id}	Delete an item
GET /docs	Interactive API docs (Swagger UI)

Project Structure

app/
├── main.py          # FastAPI app + Flask mount
├── config.py        # App configuration
├── db.py            # SQLAlchemy engine and session
├── models.py        # ORM models
├── api/
│   └── items.py     # Items REST API router
└── web/
    ├── routes.py    # Flask blueprints and routes
    ├── static/      # CSS assets
    └── templates/   # Jinja2 HTML templates