If you've been browsing the web recently, you've probably noticed a new kind of permission prompt popping up: "This site wants to access devices on your local network." It showed up for me on a random dashboard I was building, and my first thought was — wait, I wrote this app, why is the browser asking me this? Turns out, this is Chrome's rollout of Private Network Access (PNA), and it's changing how web apps interact with local resources. If you're a developer who builds anything that talks to localhost, IoT devices, printers, or internal APIs, you need to understand this. What's Actually Happening Private Network Access is a security specification (formerly known as CORS-RFC1918) that prevents public websites from silently making requests to resources on your private or local network.…