I want a screen brightness API

With COVID-19, a growing number of “contactless” solutions are being brought to market quickly. Barcodes, QR codes, and similar solutions are a cheap and easy to build, but require one thing: a bright screen. I want a screen brightness API such that only when an app is visible/active (to avoid abuse) it can maximize screen brightness for a scanner to read something on the screen, then return to regular brightness. With this API, ticketing, payments, and other ID scenarios can be quickly built out and used without the need for a long-term installed app or without the ceremony of darker screens and the speed decrease that brings to lines and queues at serving lines and events.