NYISO Finance Metering API
The Metering component of NYISO's Finance APIs - submission and retrieval of hourly revenue-grade meter data for generators, ties and subzones, plus retrieval of calculated subzone load in summary and detail form, transmission owner load submission, retrieval and verification, generator performance data, and minimum oil burn events. JSON request and response bodies, ISO-8601 dates and times with Eastern offsets, up to four decimals of MWh precision, HTTPS 1.1 over TLS 1.2. Documented operations include POST and GET /v1/powerMetering, GET /v1/calculatedSubzoneLoad/summary and /detail, POST and GET /v1/transmissionOwnerLoad, GET /v1/transmissionOwnerLoad/verification/summary and /detail, GET /v1/generatorPerformance, and GET plus POST on /v1/minOilBurnEvent and its /generator and /transmissionOwner variants. This API replaced the retired SDX upload/download application, which NYISO withdrew on 2025-09-17. Access is restricted to NYISO market participants - two-factor, requiring a valid MIS user account and password over HTTP Basic plus the NAESB certificate associated with that account on every request. All endpoints returned 401 Authorization Required to anonymous probes on 2026-07-27. A market-trial environment exists at apitest.nyiso.com and also answered 401.