HTTP status codes / 2xx — Success
Success, but the payload was modified by a transforming proxy.
The response is a 200-style success whose metadata or body was transformed by an intermediary (e.g. a caching proxy that rewrote headers). Rare in modern APIs.
If you see 203 unexpectedly, look at what sits between you and the origin — usually a proxy.
The fastest way to pin down a 203 is to reproduce the exact request and inspect what actually went over the wire — status, headers, timing and body, without your app code in the way. That is what an API client is for; ReqPad does it from your phone, with every request saved to history.
200 OK · 201 Created · 202 Accepted · 204 No Content · 205 Reset Content · 206 Partial Content — or the full reference.
Build the request, send it, read status + headers + timing — on your iPhone. Free to start.