The SAS %mpeinit macro dumps work.browser_url_vars and work.browser_info to the log when _debug is on (2477, fields,log,trace, 131 or 128). The JS mocks had no equivalent, so a mocked session could not show what the client sent. Add mpeinit() to dcMockUtils.js and call it at the bottom of the file - the same place the SAS services call %mpeinit - so every mock service that eval()s the utilities dumps the two input tables. console.log output is returned in the request log, so it lands in Data Controller's SAS Log tab exactly as the SAS version does. The tables are read with fetchRaw, so both the JSON body shape and the multipart _WEBIN_NAME / _WEBIN_FILEREF shape work. Values are dumped with the same NOTE: prefixes and name=value formatting as the macro.