ISO New England

ISO New England Hourlylmp API

24 path template(s) under /hourlylmp in the published ISO New England Web Services API v1.1 documentation.

Documentation GitHub OpenAPI

Operations 24

GET /hourlylmp/da/final Default resource #

GET /hourlylmp/da/final/current Get the current Final Hourly LMPs for Hub, Load Zones, and External Nodes #

GET /hourlylmp/da/final/current/all Get the current Final Hourly LMPs for all locations #

GET /hourlylmp/da/final/current/location/{locationId} Get the current Final Da Hourly LMPs for a given location #

GET /hourlylmp/da/final/day/latest Get the latest published day's DA Final Hourly LMPs for all locations #

GET /hourlylmp/da/final/day/{day} GET /hourlylmp/da/final/day/{day} #

GET /hourlylmp/da/final/day/{day}/hour/{sh} GET /hourlylmp/da/final/day/{day}/hour/{sh} #

GET /hourlylmp/da/final/day/{day}/location/{locationId} Get the current Final Da Hourly LMPs for a given location #

GET /hourlylmp/da/final/info Get the Service Info for Final Da Hourly LMPs #

GET /hourlylmp/rt/final Default resource #

GET /hourlylmp/rt/final/day/{day} GET /hourlylmp/rt/final/day/{day} #

GET /hourlylmp/rt/final/day/{day}/hour/{sh} GET /hourlylmp/rt/final/day/{day}/hour/{sh} #

GET /hourlylmp/rt/final/day/{day}/location/{locationId} Get the current Final RT Hourly LMPs for day for location #

GET /hourlylmp/rt/final/info Get the Service Info for Final Rt Hourly LMPs #

GET /hourlylmp/rt/prelim Default resource #

GET /hourlylmp/rt/prelim/current Get the current Prelim RT Hourly LMPs for Hub, Load Zones, and External Nodes #

GET /hourlylmp/rt/prelim/current/all Get the current Prelim RT Hourly LMPs for all locations #

GET /hourlylmp/rt/prelim/current/location/{locationId} Get the current Prelim RT Hourly LMPs for a given location #

GET /hourlylmp/rt/prelim/day/{day} Get the current Prelim RT Hourly LMPs for a given Date #

GET /hourlylmp/rt/prelim/day/{day}/hour/{sh} GET /hourlylmp/rt/prelim/day/{day}/hour/{sh} #

GET /hourlylmp/rt/prelim/day/{day}/location/{locationId} Get the current Prelim RT Hourly LMPs for a given location #

GET /hourlylmp/rt/prelim/info Get the Service Info for Prelim RT Hourly LMPs #

GET /hourlylmp/rt/prelim/previous Get the previous interval Prelim RT Hourly LMPs for Hub, Load Zones, and… #

GET /hourlylmp/rt/prelim/previous/all Get the previous interval Prelim RT Hourly LMPs for all locations #

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OpenAPI Specification

openapi: 3.2.0
info:
  title: ISO New England Web Services API v1.1 Hourlylmp API
  version: '1.1'
  description: RESTful interface to ISO New England energy and market data.
  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: hourlylmp
  description: 24 path template(s) under /hourlylmp in the published ISO New England Web Services API v1.1 documentation.
paths:
  /hourlylmp/da/final:
    get:
      operationId: getHourlylmpDaFinal
      summary: Default resource
      description: Default resource. Redirects to Final RT LMP Info.
      tags:
      - hourlylmp
      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.hourlylmp.da.final.html
        harvested: '2026-07-27'
  /hourlylmp/da/final/current:
    get:
      operationId: getHourlylmpDaFinalCurrent
      summary: Get the current Final Hourly LMPs for Hub, Load Zones, and External Nodes
      description: Get the current Final Hourly LMPs for Hub, Load Zones, and External Nodes.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the current Final Da Hourly Lmps.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.da.final.current.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
  /hourlylmp/da/final/current/all:
    get:
      operationId: getHourlylmpDaFinalCurrentAll
      summary: Get the current Final Hourly LMPs for all locations
      description: Get the current Final Hourly LMPs for all locations.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the current Final Da Hourly Lmps.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.da.final.current.all.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
  /hourlylmp/da/final/current/location/{locationId}:
    get:
      operationId: getHourlylmpDaFinalCurrentLocationByLocationId
      summary: Get the current Final Da Hourly LMPs for a given location
      description: Get the current Final Da Hourly LMPs for a given location.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the current Final Da Hourly LMP for the given location.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmp'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmp'
        '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.hourlylmp.da.final.current.location.locationId.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmp
      parameters:
      - name: locationId
        in: path
        required: true
        schema:
          type: string
        description: The location id
  /hourlylmp/da/final/day/latest:
    get:
      operationId: getHourlylmpDaFinalDayLatest
      summary: Get the latest published day's DA Final Hourly LMPs for all locations
      description: Get the latest published day's DA Final Hourly LMPs for all locations.
      tags:
      - hourlylmp
      responses:
        '200':
          description: Successful response.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.da.final.day.latest.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
  /hourlylmp/da/final/day/{day}:
    get:
      operationId: getHourlylmpDaFinalDayByDay
      summary: GET /hourlylmp/da/final/day/{day}
      description: (no documentation provided)
      tags:
      - hourlylmp
      responses:
        '200':
          description: Successful response.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.da.final.day.day.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
      parameters:
      - name: day
        in: path
        required: true
        schema:
          type: string
  /hourlylmp/da/final/day/{day}/hour/{sh}:
    get:
      operationId: getHourlylmpDaFinalDayByDayHourBySh
      summary: GET /hourlylmp/da/final/day/{day}/hour/{sh}
      description: (no documentation provided)
      tags:
      - hourlylmp
      responses:
        '200':
          description: Successful response.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.da.final.day.day.hour.sh.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
      parameters:
      - name: day
        in: path
        required: true
        schema:
          type: string
      - name: sh
        in: path
        required: true
        schema:
          type: string
  /hourlylmp/da/final/day/{day}/location/{locationId}:
    get:
      operationId: getHourlylmpDaFinalDayByDayLocationByLocationId
      summary: Get the current Final Da Hourly LMPs for a given location
      description: Get the current Final Da Hourly LMPs for a given location.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the current Final Da Hourly LMP for the given location.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.da.final.day.day.location.locationId.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
      parameters:
      - name: day
        in: path
        required: true
        schema:
          type: string
        description: The day to retrieve data for (YYYYMMDD)
      - name: locationId
        in: path
        required: true
        schema:
          type: string
        description: The location id
  /hourlylmp/da/final/info:
    get:
      operationId: getHourlylmpDaFinalInfo
      summary: Get the Service Info for Final Da Hourly LMPs
      description: Get the Service Info for Final Da Hourly LMPs.
      tags:
      - hourlylmp
      responses:
        '200':
          description: the ServiceInfoElement for Final Da Houry LMPs.
          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.hourlylmp.da.final.info.html
        harvested: '2026-07-27'
      x-xml-element: ServiceInfo
  /hourlylmp/rt/final:
    get:
      operationId: getHourlylmpRtFinal
      summary: Default resource
      description: Default resource. Redirects to Final RT Hourly LMP Info.
      tags:
      - hourlylmp
      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.hourlylmp.rt.final.html
        harvested: '2026-07-27'
  /hourlylmp/rt/final/day/{day}:
    get:
      operationId: getHourlylmpRtFinalDayByDay
      summary: GET /hourlylmp/rt/final/day/{day}
      description: (no documentation provided)
      tags:
      - hourlylmp
      responses:
        '200':
          description: Successful response.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.rt.final.day.day.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
      parameters:
      - name: day
        in: path
        required: true
        schema:
          type: string
  /hourlylmp/rt/final/day/{day}/hour/{sh}:
    get:
      operationId: getHourlylmpRtFinalDayByDayHourBySh
      summary: GET /hourlylmp/rt/final/day/{day}/hour/{sh}
      description: (no documentation provided)
      tags:
      - hourlylmp
      responses:
        '200':
          description: Successful response.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.rt.final.day.day.hour.sh.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
      parameters:
      - name: day
        in: path
        required: true
        schema:
          type: string
      - name: sh
        in: path
        required: true
        schema:
          type: string
  /hourlylmp/rt/final/day/{day}/location/{locationId}:
    get:
      operationId: getHourlylmpRtFinalDayByDayLocationByLocationId
      summary: Get the current Final RT Hourly LMPs for day for location
      description: Get the current Final RT Hourly LMPs for day for location .
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the current Final RT Hourly LMPs.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.rt.final.day.day.location.locationId.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
      parameters:
      - name: day
        in: path
        required: true
        schema:
          type: string
        description: The day to retrieve data for (YYYYMMDD)
      - name: locationId
        in: path
        required: true
        schema:
          type: string
        description: The location id
  /hourlylmp/rt/final/info:
    get:
      operationId: getHourlylmpRtFinalInfo
      summary: Get the Service Info for Final Rt Hourly LMPs
      description: Get the Service Info for Final Rt Hourly LMPs.
      tags:
      - hourlylmp
      responses:
        '200':
          description: the ServiceInfoElement for Five Minute LMPs.
          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.hourlylmp.rt.final.info.html
        harvested: '2026-07-27'
      x-xml-element: ServiceInfo
  /hourlylmp/rt/prelim:
    get:
      operationId: getHourlylmpRtPrelim
      summary: Default resource
      description: Default resource. Redirects to Prelim RT Hourly LMP Info.
      tags:
      - hourlylmp
      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.hourlylmp.rt.prelim.html
        harvested: '2026-07-27'
  /hourlylmp/rt/prelim/current:
    get:
      operationId: getHourlylmpRtPrelimCurrent
      summary: Get the current Prelim RT Hourly LMPs for Hub, Load Zones, and External Nodes
      description: Get the current Prelim RT Hourly LMPs for Hub, Load Zones, and External Nodes.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the current Prelim RT Hourly LMPs.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.rt.prelim.current.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
  /hourlylmp/rt/prelim/current/all:
    get:
      operationId: getHourlylmpRtPrelimCurrentAll
      summary: Get the current Prelim RT Hourly LMPs for all locations
      description: Get the current Prelim RT Hourly LMPs for all locations.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the current Prelim RT Hourly LMPs.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.rt.prelim.current.all.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
  /hourlylmp/rt/prelim/current/location/{locationId}:
    get:
      operationId: getHourlylmpRtPrelimCurrentLocationByLocationId
      summary: Get the current Prelim RT Hourly LMPs for a given location
      description: Get the current Prelim RT Hourly LMPs for a given location.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpElement containing the current Prelim RT Hourly LMP for the given location.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmp'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmp'
        '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.hourlylmp.rt.prelim.current.location.locationId.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmp
      parameters:
      - name: locationId
        in: path
        required: true
        schema:
          type: string
        description: The location id
  /hourlylmp/rt/prelim/day/{day}:
    get:
      operationId: getHourlylmpRtPrelimDayByDay
      summary: Get the current Prelim RT Hourly LMPs for a given Date
      description: Get the current Prelim RT Hourly LMPs for a given Date.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the current Prelim RT Hourly LMP for the given date .
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.rt.prelim.day.day.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
      parameters:
      - name: day
        in: path
        required: true
        schema:
          type: string
        description: The day to retrieve data for (YYYYMMDD)
  /hourlylmp/rt/prelim/day/{day}/hour/{sh}:
    get:
      operationId: getHourlylmpRtPrelimDayByDayHourBySh
      summary: GET /hourlylmp/rt/prelim/day/{day}/hour/{sh}
      description: (no documentation provided)
      tags:
      - hourlylmp
      responses:
        '200':
          description: Successful response.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.rt.prelim.day.day.hour.sh.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
      parameters:
      - name: day
        in: path
        required: true
        schema:
          type: string
      - name: sh
        in: path
        required: true
        schema:
          type: string
  /hourlylmp/rt/prelim/day/{day}/location/{locationId}:
    get:
      operationId: getHourlylmpRtPrelimDayByDayLocationByLocationId
      summary: Get the current Prelim RT Hourly LMPs for a given location
      description: Get the current Prelim RT Hourly LMPs for a given location.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the current Prelim RT Hourly LMP for the given date and location.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.rt.prelim.day.day.location.locationId.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
      parameters:
      - name: day
        in: path
        required: true
        schema:
          type: string
        description: The day to retrieve data for (YYYYMMDD)
      - name: locationId
        in: path
        required: true
        schema:
          type: string
        description: The location id
  /hourlylmp/rt/prelim/info:
    get:
      operationId: getHourlylmpRtPrelimInfo
      summary: Get the Service Info for Prelim RT Hourly LMPs
      description: Get the Service Info for Prelim RT Hourly LMPs.
      tags:
      - hourlylmp
      responses:
        '200':
          description: the ServiceInfoElement for Prelim Rt Hourly LMPs.
          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.hourlylmp.rt.prelim.info.html
        harvested: '2026-07-27'
      x-xml-element: ServiceInfo
  /hourlylmp/rt/prelim/previous:
    get:
      operationId: getHourlylmpRtPrelimPrevious
      summary: Get the previous interval Prelim RT Hourly LMPs for Hub, Load Zones, and…
      description: Get the previous interval Prelim RT Hourly LMPs for Hub, Load Zones, and External Nodes.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the previous interval Prelim RT Hourly LMPs.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.rt.prelim.previous.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
  /hourlylmp/rt/prelim/previous/all:
    get:
      operationId: getHourlylmpRtPrelimPreviousAll
      summary: Get the previous interval Prelim RT Hourly LMPs for all locations
      description: Get the previous interval Prelim RT Hourly LMPs for all locations.
      tags:
      - hourlylmp
      responses:
        '200':
          description: a HourlyLmpsElement containing the previous interval Prelim RT Hourly LMPs.
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
            application/json:
              schema:
                $ref: '#/components/schemas/HourlyLmps'
        '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.hourlylmp.rt.prelim.previous.all.html
        harvested: '2026-07-27'
      x-xml-element: HourlyLmps
components:
  schemas:
    Lmp:
      type: object
      properties:
        BeginDate:
          type: string
          format: date-time
        Location:
          $ref: '#/components/schemas/LocationRef'
        LmpTotal:
          type: number
        EnergyComponent:
          type: number
        CongestionComponent:
          type: number
        LossComponent:
          type: number
      required:
      - BeginDate
      - Location
      x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_Lmp
    HourlyLmp:
      $ref: '#/components/schemas/Lmp'
      x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_HourlyLmp
    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
    HourlyLmps:
      type: object
      properties:
        HourlyLmp:
          type: array
          items:
            $ref: '#/components/schemas/HourlyLmp'
      x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_HourlyLmps
  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

ISO New England Hourlylmp API

Operations 24

Documentation

Specifications

Schemas & Data

Other Resources