I have a web application built with JavaScript and PHP, and now I have a requirement to create a system for tracking workers’ clock-in and clock-out times in the field. The idea is that workers will register their fingerprints, and then the foreman will use a fingerprint scanner to log both entry and exit times along with the corresponding hours.

The system needs to scan fingerprints when workers arrive and leave. Since this is for fieldwork, it must be portable and should be done using mobile phones. The idea is to use external hardware to keep it consistent, avoiding issues with varying quality of fingerprint readers on different phones.

I’m mentioning the web app built with JS because, in the near future, we plan to package it using Cordova or Capacitor, and ideally, we’d like to handle everything from the same application without having to install a second app on the phone. As for the PHP backend, the hardware should authenticate the device, check if the employee is registered on the backend, and log the working hours. However, I have no idea how this information would be sent. Maybe a photo?

Since I have no experience with this kind of system, I’m not sure how to approach the problem or what type of hardware to look for. Obviously, I wouldn’t program the hardware with PHP or JS, but with the SDK language it offers.