sgqrgen 0.1.2

A Python library to parse, modify, and generate SGQR (Singapore Quick Response) codes.

SGQR Generator: Singapore Bank Friendly

A Python package for parsing, modifying, and generating SGQR (Singapore Quick Response) codes.

SGQR is a unified payment QR code standard used in Singapore. It wraps various payment schemes (e.g. PayNow, NETS, GrabPay) using a Tag-Length-Value (TLV) encoding format. This library allows you to easily load an SGQR payload, update its fields (like transaction amount or payment reference), and generate a new, valid SGQR payload with a recomputed CRC16 checksum.

Installation

Install the package via pip or your favorite package manager:

pip install sgqrgen

Or with uv:

uv add sgqrgen

Quick Start

1. Using a Singapore Bank App (e.g. UOB TMRW), generate a MyQR code for payment

   1. For example, using UOB TMRW on the iPhone (updated as of 2026-06-15).
   2. Open and login to UOB TMRW app.
   3. Tap Scan to pay.
   4. On top top menu bar, choose MR QR.
   5. Scan the QR code generated using any QR Reader.
   6. Get the string sgqr_str = "00020101021125280009SG.PAYNOW010100211+659876543203011530370254040.005802SG5913TAN AH GAO 63042968"

2. Create an instance of the SgQRGenerator class with the initial_string.

3. Here is a simple example of how to parse an existing SGQR code, modify the price and comment, and output the updated QR code image:

   from decimal import Decimal
   from sgqrgen import SgQRGenerator
   
   # Initial SGQR string (e.g. PayNow merchant QR code)
   sgqr_str = "00020101021125280009SG.PAYNOW010100211+659876543203011530370254040.005802SG5913TAN AH GAO 63042968"
   
   # Initialize generator
   qr_gen = SgQRGenerator(sgqr_str)
   
   # Modify amount to $8.00 and set comment/reference to "membership"
   qr_gen.change_price(Decimal("8.00")).change_comment("membership")
   
   # Export updated QR code image
   qr_gen.output_qrcode("output-qrcode.png")
   
   # Get updated raw SGQR string payload
   print("Updated payload:", qr_gen.qr)
   

Features

• TLV Parsing: Easily decodes standard Tag-Length-Value SGQR payloads.
• Price Modification: Update the transaction amount dynamically (Tag 54) with automatic formatting.
• Comment/Reference Update: Add or update payment reference notes (Tag 62 / Sub-tag 01).
• CRC16 Verification: Automatic recomputation of the CRC16 checksum (Tag 63) when the payload is built/modified.
• High-Quality QR Image Generation: Utilizes segno to export QR codes in high-resolution scales.

License

This project is licensed under the MIT License - see the LICENSE file for details.