QR Code Generator API

A simple and powerful API for generating customizable QR codes from text or URLs, built with FastAPI.

Features

• Built with FastAPI - modern, fast Python web framework
• Interactive API documentation with OpenAPI and Swagger UI
• Generate QR codes from any text or URL
• Customize size (S, M, L)
• Adjust margins/borders
• Multiple error correction levels (L, M, Q, H)
• Returns QR code as PNG image
• Asynchronous request handling

Installation

Prerequisites

• Python 3.10 or higher
• pip (Python package manager)

Step 1: Clone the repository

git clone https://github.com/heirro/qrcode-generator-api.git
cd qrcode-generator-api

Step 2: Set up a virtual environment (optional but recommended)

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

# For macOS/Linux
python3 -m venv venv
source venv/bin/activate

Step 3: Install initial dependencies

First, install FastAPI with all standard dependencies and wheel:

pip install "fastapi[standard]"
pip install wheel

Step 4: Install remaining dependencies

pip install -r requirements.txt

Running the API

Start the FastAPI server:

fastapi dev main.py

The API will be available at http://localhost:8000/

API Usage

Generate a QR Code

GET /api/create

Parameters:

• data (required): The text or URL to encode in the QR code
• size (optional): QR code size - S (small), M (medium), or L (large)
• margin (optional): Border width around the QR code
• error_level (optional): Error correction level - L (Low, 7% recovery), M (Medium, 15% recovery), Q (Quartile, 25% recovery), H (High, 30% recovery)

Example Usage:

# Basic QR code for a URL
http://localhost:8000/api/create?data=https://example.com

# Customized QR code
http://localhost:8000/api/create?data=https://example.com&size=L&margin=2&error_level=H

API Documentation

One of the best features of FastAPI is the automatic interactive documentation:

• Swagger UI documentation: http://localhost:8000/
• Try out API endpoints directly from your browser
• Explore all available parameters and options

Deployment

FastAPI applications can be easily deployed:

# Production server
fastapi run main:app --host 0.0.0.0 --port 8000

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Live Server

Demo: https://qrcode.heirro.dev

Example Usage:

# Basic QR code for a URL
https://qrcode.heirro.dev/api/create?data=https://example.com

# Customized QR code
https://qrcode.heirro.dev/api/create?data=https://example.com&size=L&margin=2&error_level=H

License

MIT