json-head. I’ve deployed another App Engine mini-app, which provides a JSON-P API for running HEAD requests against an arbitrary URL (useful for checking things like Content-Length and Content-Type headers and whether a URL returns 200). App Engine’s urlfetch limitations mean it can only deal with port 80 and 443 requests.
Recent articles
- Phoenix.new is Fly's entry into the prompt-driven app development space - 23rd June 2025
- Trying out the new Gemini 2.5 model family - 17th June 2025
- The lethal trifecta for AI agents: private data, untrusted content, and external communication - 16th June 2025