openapi: 3.2.0 info: title: ISO New England Web Services API v1.1 Weeklylmpindex API version: '1.1' description: RESTful interface to ISO New England energy and market data. This OpenAPI document was DERIVED by API Evangelist from ISO New England's own published, machine-generated Enunciate technical documentation at https://webservices.iso-ne.com/docs/v1.1/ and the two XML Schemas it publishes (ns0.xsd, ns1.xsd, saved verbatim under schemas/). ISO New England does not publish an OpenAPI definition; the only provider-published machine-readable description of the interface is a WADL at https://webservices.iso-ne.com/api/v1.1?_wadl&_type=xml, which sits behind the same HTTP Basic authentication as the API and returned HTTP 401 to anonymous probes. Every path, method, parameter, description, media type and schema in this document is copied from the provider's published sources; nothing was invented. Each operation carries x-evidence naming the exact documentation page it came from. All feeds are available in XML and JSON, selected by adding a .xml or .json extension to the request URL or by sending an Accept header of application/xml or application/json. contact: name: ISO New England Ask ISO url: https://askiso.iso-ne.com/s/ x-provenance: method: derived derived_by: API Evangelist enrichment pipeline derived_on: '2026-07-27' sources: - https://webservices.iso-ne.com/docs/v1.1/ - https://webservices.iso-ne.com/docs/v1.1/ns0.xsd - https://webservices.iso-ne.com/docs/v1.1/ns1.xsd - https://www.iso-ne.com/participate/support/web-services-data not_provider_published: true note: Derived from provider-published HTML documentation and XSDs. Not an ISO New England artifact. servers: - url: https://webservices.iso-ne.com/api/v1.1 description: Production base path (HTTP Basic over SSL) security: - basicAuth: [] tags: - name: weeklylmpindex description: 4 path template(s) under /weeklylmpindex in the published ISO New England Web Services API v1.1 documentation. paths: /weeklylmpindex: get: operationId: getWeeklylmpindex summary: Default resource description: Default resource. Redirects to Weekly LMP Index Info. tags: - weeklylmpindex responses: '200': description: Successful response. content: application/xml: schema: description: Response payload is not described in the published documentation. application/json: schema: description: Response payload is not described in the published documentation. '401': description: Unauthorized - HTTP Basic credentials from an ISO Express account are required. Verified by anonymous probe on 2026-07-27. x-evidence: source: https://webservices.iso-ne.com/docs/v1.1/rest.weeklylmpindex.html harvested: '2026-07-27' /weeklylmpindex/current: get: operationId: getWeeklylmpindexCurrent summary: Get current WeeklyLmpIndexes for Service Type description: Get current WeeklyLmpIndexes for Service Type. tags: - weeklylmpindex responses: '200': description: a WeeklyLmpIndexsElement containing the current WeeklyLmpIndexs. content: application/xml: schema: $ref: '#/components/schemas/WeeklyLmpIndexes' application/json: schema: $ref: '#/components/schemas/WeeklyLmpIndexes' '401': description: Unauthorized - HTTP Basic credentials from an ISO Express account are required. Verified by anonymous probe on 2026-07-27. x-evidence: source: https://webservices.iso-ne.com/docs/v1.1/rest.weeklylmpindex.current.html harvested: '2026-07-27' x-xml-element: WeeklyLmpIndexes /weeklylmpindex/info: get: operationId: getWeeklylmpindexInfo summary: Get the Service Info for Weekly LMP Index description: Get the Service Info for Weekly LMP Index. tags: - weeklylmpindex responses: '200': description: the ServiceInfoElement for Weekly LMP Index. content: application/xml: schema: $ref: '#/components/schemas/ServiceInfo' application/json: schema: $ref: '#/components/schemas/ServiceInfo' '401': description: Unauthorized - HTTP Basic credentials from an ISO Express account are required. Verified by anonymous probe on 2026-07-27. x-evidence: source: https://webservices.iso-ne.com/docs/v1.1/rest.weeklylmpindex.info.html harvested: '2026-07-27' x-xml-element: ServiceInfo /weeklylmpindex/year/{year}: get: operationId: getWeeklylmpindexYearByYear summary: Get an entire Years WeeklyLmpIndexs description: Get an entire Years WeeklyLmpIndexs. tags: - weeklylmpindex responses: '200': description: a WeeklyLmpIndexsElement containing the WeeklyLmpIndexs. content: application/xml: schema: $ref: '#/components/schemas/WeeklyLmpIndexes' application/json: schema: $ref: '#/components/schemas/WeeklyLmpIndexes' '401': description: Unauthorized - HTTP Basic credentials from an ISO Express account are required. Verified by anonymous probe on 2026-07-27. x-evidence: source: https://webservices.iso-ne.com/docs/v1.1/rest.weeklylmpindex.year.year.html harvested: '2026-07-27' x-xml-element: WeeklyLmpIndexes parameters: - name: year in: path required: true schema: type: string components: schemas: WeeklyLmpIndexes: type: object properties: WeeklyLmpIndex: type: array items: $ref: '#/components/schemas/WeeklyLmpIndex' x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_WeeklyLmpIndexes WeeklyLmpIndex: type: object properties: BeginDate: type: string format: date-time Location: $ref: '#/components/schemas/LocationRef' DaOnPeakLMP: type: number DaOffPeakLMP: type: number DaAverageLMP: type: number RtOnPeakLMP: type: number RtOffPeakLMP: type: number RtAverageLMP: type: number required: - BeginDate - Location x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_WeeklyLmpIndex LocationRef: type: object properties: $: type: string description: Element text value (serialized as "$" in the JSON representation, per observed API responses). '@LocId': type: integer '@LocType': type: string enum: - NETWORK AREA - LOAD ZONE - NETWORK NODE - HUB - HUB NODE - RELIABILITY REGION - EXT. NODE - RESERVE ZONE - SYSTEM - INT. AREA - EXT. AREA - DISPATCH ZONE - CAPACITY ZONE - DRRAZ - DRR AGGREGATION ZONE required: - '@LocId' x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_LocationRef ServiceInfo: type: object properties: LatestBeginDate: type: string format: date-time CreationDate: type: string format: date-time required: - LatestBeginDate - CreationDate x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_ServiceInfo securitySchemes: basicAuth: type: http scheme: basic description: HTTP Basic Authentication over SSL. Credentials come from a free, self-serve ISO Express account; ISO New England states that ISO Express account holders are automatically granted access to the public data feeds. See https://www.iso-ne.com/participate/applications-status-changes/access-software-systems