CSP Allow-list Experiment

Tool: CSP Allow-list Experiment An experiment that shows that you can load an app in a CSP-protected sandboxed iframe (see previous note) and have a custom fetch() that intercepts CSP errors and passes them up to the parent window... which can then prompt the user to add that domain to an allow-list and then refresh the page. I built this one with GPT-5.5 xhigh running in the Codex desktop app. Tags: content-security-policy, iframes, security