Fluxzy Desktop

Fluxzy Desktop is an HTTP and HTTPS debugging proxy for Windows, macOS, and Linux. If you already use Fiddler, Charles, or Proxyman, you know the drill: capture traffic, inspect requests and responses, tweak them, replay them. Fluxzy does all of that, with support for HTTP/1.1, HTTP/2, WebSocket, gRPC, and SSE.

The difference is that Fluxzy doesn't have to run as a proxy at all. It can capture traffic transparently, without touching system proxy settings. That solves the usual headache where a mobile app or a Flutter build ignores your proxy config and shows you nothing. You can still run it as a classic proxy if you prefer, but you don't have to. It also preserves the client TLS fingerprint, so servers that fingerprint clients to detect bots behave the same way during inspection as they do in real use.

Other things you get: native PCAP capture with TLS keys, ready to open in Wireshark. A YAML rule engine for rewriting requests and responses. Breakpoints, mock responses, and export to HAR, SAZ, cURL, and .http. It runs fully offline. No login, no cloud, no subscription. The engine underneath, Fluxzy.Core, is open source. Free for personal use, one-time license for professional use.