leofah / stustapay

Electronic Payment System for Festivals using NFC Wristbands

StuStaPay

Electronic Payment System for Festivals, developed for StuStaCulum

Use NFC wristbands to quickly pay at events!

Idea

• Free software digital payment system for festivals
• Every user has a NFC chip (in their wristband)
• Users can top up their credit via Cash, card or online payment services
• They can buy products at points of sales, where their credits are deduced
• Designed to comply with German fiscal laws (digital signatures with TSE)

Documentation

• Installation guide
• Core
• App
• Management Website
• User Self-Service Portal

Components

Core

All transactions go through the core.

Database

The database ensures transaction-safe handling of the payment processing logic. It's the source of truth for account funds, order processing and offered products.

Core Server

Python tool which handles PoS requests over websocket.

TSE signatures

All transactions need to be signed by a federally approved security module (as defined by Kassensicherungsverordnung - KassenSichV)

App

• Operated at points of sale
• Is connected via websocket to StuStaPay core
• Registers customer's orders
• Can scan and validate NFC tags

Webapps

Each one run on separate Python webserver, which talks to the core database.

Administration site

Configuration of products, cash desks, accounts, ...

User Self Service Portal

• Top up account with online payment
• Get payment reciepes
• Pay back money after the event

Tech stack

Core

• Python
• PostgreSQL DB
• asyncpg
• FastAPI
• uvicorn

TSE integration

• TSE hardware module

Ordering Terminal

• Android telephone with NFC reader
• Kotlin
• jetpack compose

Webapps for Management and User Self-Service

• react
• nodejs

License

Released under the GNU Affero General Public License version 3 or later, see authors and license for details.