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