HTTP headers / request & response
X-Request-Id: 7f23a1b4-…
A correlation ID for one request across services and logs. Conventionally echoed back in the response.
Not standard — names vary (X-Correlation-Id, traceparent for W3C tracing). Log it on errors; support teams will love you.
The fastest way to see what X-Request-Id is actually doing is to send the request and read both sides raw — ReqPad shows auto-generated and custom headers for every request, on all six protocols, with history. Related references: status codes · Content-Type · Content-Length · Cache-Control · Connection
Build the request, send it, read raw headers and timing — from your iPhone. Free to start.