CORS for Firefox Extensions: A Real-World Before/After
Firefox extensions sit in a weird spot for CORS. They look like frontend code, but they also get privileged access that normal web pages do not. That mismatch trips people up all the time. I’ve seen the same bug report more than once: “The API works in my extension background script, but fails in the popup.” “It works in Chrome, but Firefox blocks it.” “Why does fetch() behave differently depending on where I call it?” ...