Today I had a custom report to fix: an external webservice was returning an error about a missing parameter. Using an example found here on the forum and comparing with the trace from "curl" (with the ascii-trace switch) I figured out what was wrong and got lucky.
Lucky because it worked but I still couldn't see what SAP was sending to the remote server: is there a way to trace connections just like with curl?
Ideally without changing the program (for example in Production) but today I would have been perfectly happy with changes to the program, since it was in a Devel system. I used cl_rest_http_client in case it matters.