I'm cautiously opening the question of how to deal with the QR Passport that is about to be introduced for internal use in NZ. It's a QR code that people store on their phone or print out.

The charity I volunteer at (doing some very simple python programming) needs to check volunteers entering the premises to see that they have a current vaccination status. We would want to do that "contactlessly" because most are elderly.

The government has issued a specification for reading the QR code (most of it over my head) and will publish a smartphone app to read it.  However, I gather that just gives a "yah or nay" answer valid only for that moment in time, see example below. But there must be a valid interval as part of that data so people don't have to scan this every time they enter their workplace.

Our volunteers currently roll up and scan their "employee" badge and my python code clocks them in, same going out.  Once we require all personnel entering to have full vaccination status I'm expecting I'll prompt them to scan their QR code as well when it's not "on file," repeated at some interval of weeks or months, hopefully not every day!  What I'll need is the python script to parse and validate the QR code.

I'd imagine this is all brand new but the spec is here: https://nzcp.covid19.health.nz/#2d-barcode-encoding-options-rational