http_convert_data(+In, +Fields, -Data, +Options) is semidet[multifile, library(http/http_client)]
Multi-file hook to convert a HTTP payload according to the Content-Type header. The default implementation deals with application/x-prolog. The HTTP framework provides implementations for JSON (library(http/http_json)), HTML/XML (library(http/http_sgml_plugin))
 http_client:http_convert_data(+In, +Fields, -Data, +Options)[multifile, library(http/http_json)]
Hook implementation that supports reading JSON documents. It processes the following option:
json_object(+As)
Where As is one of term or dict. If the value is dict, json_read_dict/3 is used.