rkd-api rkd data api news query-string rics fundamentals historical quote token fields json c# python search http php time-series java websockets soap-api symbology fiddler authentication perl commodities document ssl trep financial-statements throttling proxy bonds street-events .net error rest-api xml documentation volatility streaming-prices bulk-download transcript Download equities pandas error-message fundamental-data news-filter pe-code trade load-balancing Service error-403 sectors kotlin timeseries derivatives FTP etf web feeds exchange-holidays api-limits economic-data disconnection upgrading time-stamp performance forex r wsdl response key timestamp request error-400 pricing helpdesk isin swagger javadoc connection-error postman