Query ISO New England (ISO-NE) five-minute real-time LMPs via the ISO-NE Web Services REST API

Steps

1. Register for ISO-NE Web Services access at https://www.iso-ne.com/participate/support/web-services-data; ISO customers and non-participants can apply for automated data access using the REST interface at the base URL https://webservices.iso-ne.com/api/v1.1.
2. Authenticate using HTTP Basic Auth with your ISO-NE web services username and password included in the Authorization header; all requests must be made over HTTPS.
3. Retrieve five-minute real-time LMPs for a specific node by calling GET /v1.1/fiveminutelmp/current/location/{locationid}; replace {locationid} with the ISO-NE location ID for the desired pricing node — retrieve the full node list from GET /v1.1/locations/all.
4. The response is available in both XML and JSON — request JSON by adding the Accept: application/json header; the response contains an array of FiveMinuteLmp objects each with BeginDate, LocationId, LmpTotal, EnergyComponent, CongestionComponent, and LossComponent.
5. For historical five-minute data, use GET /v1.1/fiveminutelmp/day/{date}/location/{locationid} where {date} is in YYYYMMDD format; this returns all 5-minute intervals for the specified operating day.
6. Implement polling at an interval aligned with the data publication cadence (approximately every 5 minutes for real-time data); use the BeginDate timestamp to detect duplicate or out-of-order records and dedup before inserting into your time-series store.