openapi: 3.2.0
info:
  title: ISO New England Web Services API v1.1 Powersystem 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: Power System
  description: 2 path template(s) under /powersystem in the published ISO New England Web Services API v1.1 documentation.
paths:
  /powersystem:
    get:
      operationId: getPowersystem
      summary: Default resource
      description: Default resource. Redirects to status.
      tags:
      - Power System
      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.powersystem.html
        harvested: '2026-07-27'
  /powersystem/status:
    get:
      operationId: getPowersystemStatus
      summary: Get the current Power System Regional Status and any current OP4 Alerts
      description: Get the current Power System Regional Status and any current OP4 Alerts.
      tags:
      - Power System
      responses:
        '200':
          description: a PowerSystemStatusElement containing the status and OP4 Alerts
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/PowerSystemStatus'
            application/json:
              schema:
                $ref: '#/components/schemas/PowerSystemStatus'
        '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.powersystem.status.html
        harvested: '2026-07-27'
      x-xml-element: PowerSystemStatus
components:
  schemas:
    PowerSystemStatus:
      type: object
      properties:
        Op4Alerts:
          $ref: '#/components/schemas/Op4Alerts'
        PowerSystemRegions:
          $ref: '#/components/schemas/PowerSystemRegions'
      required:
      - PowerSystemRegions
      x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_PowerSystemStatus
    PowerSystemRegion:
      type: object
      properties:
        RegionId:
          type: integer
        RegionName:
          type: string
        Status:
          type: string
          enum:
          - Normal
          - Power Caution
          - Power Watch
          - Power Warning
          - Cold Weather Watch Conditions
          - Cold Weather Warning Conditions
          - Cold Weather Event Conditions
          - Master/Local Control Center 2 Alert
          - Energy Emergency
        StatusDescription:
          type: string
        DateUpdated:
          type: string
          format: date-time
      required:
      - RegionId
      - RegionName
      - Status
      - StatusDescription
      - DateUpdated
      x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_PowerSystemRegion
    PowerSystemRegions:
      type: object
      properties:
        PowerSystemRegion:
          type: array
          items:
            $ref: '#/components/schemas/PowerSystemRegion'
      x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_PowerSystemRegions
    Op4Alert:
      type: object
      properties:
        AlertId:
          type: integer
        Status:
          type: string
          enum:
          - Caution
          - Watch
          - Warning
        Action:
          type: string
          enum:
          - Action 1
          - Action 2
          - Action 3
          - Action 4
          - Action 5
          - Action 6
          - Action 7
          - Action 8
          - Action 9
          - Action 10
          - Action 11
        ActionDescription:
          type: string
        DateInEffect:
          type: string
          format: date-time
        TimeIn:
          type: string
        TimeOut:
          type: string
      required:
      - AlertId
      - Status
      - Action
      - ActionDescription
      - DateInEffect
      - TimeIn
      - TimeOut
      x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_Op4Alert
    Op4Alerts:
      type: object
      properties:
        Op4Alert:
          type: array
          items:
            $ref: '#/components/schemas/Op4Alert'
      x-xsd-source: schemas/iso-new-england-web-services-ns0.xsd#type_Op4Alerts
  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