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