AESO Merit Order API

openapi: 3.2.0
info:
  title: Energy Report Merit Order API
  description: Fetch Energy Merit Order snapshot data
  version: v1
servers:
- url: https://apimgw.aeso.ca/public/energymeritorder-api
- url: https://gateway-apim.aeso.ca/public/energymeritorder-api
security:
- {}
- apiKeyHeader: []
- apiKeyQuery: []
tags:
- name: MeritOrder
paths:
  /meritOrder/energy:
    get:
      operationId: getMeritOrderReport
      summary: Fetch Energy Merit Order snapshot data for a given date that is 60 days prior to current date.
      description: "Fetch Energy Merit Order snapshot data for Date(startDate (yyyy-MM-dd)) \n\nThe EMMO snapshot data is available 60 days after the date of the snapshot, first available from September 1, 2009. \n\nThe data from 1-Sep-2009 to 1-Sep-2014 is the Merit Order at the 30th min. of the settlement interval. \n\nThe data after 1-Sep-2014 is the last Merit Order of the settlement interval.\n"
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EnergyMeritOrderReport'
              examples:
                default:
                  value:
                    data:
                    - begin_dateTime_utc: string
                      begin_dateTime_mpt: string
                      energy_blocks:
                      - import_or_export: string
                        asset_ID: string
                        block_number: 0
                        block_price: 0
                        from_MW: 0
                        to_MW: 0
                        block_size: 0
                        available_MW: 0
                        dispatched?: string
                        dispatched_MW: 0
                        flexible?: string
                        offer_control: string
        '400':
          description: Bad Request
        '401':
          description: Unauthorized
        '403':
          description: Forbidden
        '404':
          description: Not Found
        '405':
          description: Invalid method
        '500':
          description: Internal server error
        '503':
          description: Service unavailable
      parameters:
      - name: startDate
        in: query
        required: true
        description: 'Any date between 2009-09-01 and 60 days prior to current date (format: yyyy-MM-dd).'
        schema:
          $ref: '#/components/schemas/MeritOrderEnergyGetRequest'
      tags:
      - MeritOrder
components:
  schemas:
    MeritOrderData:
      type: object
      properties:
        begin_dateTime_utc:
          type: string
          description: Beginning of the settlement hour that the Energy Market Merit Order applies to, in Coordinated Universal Time (UTC) time
        begin_dateTime_mpt:
          type: string
          description: Beginning of the settlement hour that the Energy Market Merit Order applies to, in Mountain prevailing time
        energy_blocks:
          type: array
          items:
            $ref: '#/components/schemas/EnergyBlocks'
    EnergyBlocks:
      type: object
      properties:
        import_or_export:
          type: string
          description: Import/Export Identifier, either 'I' for Import or 'E' for Export
        asset_ID:
          type: string
          description: Asset's unique short name defined by 3 or 4-digit alphanumeric code. A pool asset is registered to a pool participant.
        block_number:
          type: integer
          description: ' Block Number from 0 to 6'
          format: int32
        block_price:
          type: number
          description: Block Offer Price (in $/MWh)
          format: double
        from_MW:
          type: integer
          description: Prior Block's cumulative Megawatt (in MW)
          format: int32
        to_MW:
          type: integer
          description: Current Block's cumulative Megawatt (in MW)
          format: int32
        block_size:
          type: integer
          description: Block Size (MW)
          format: int32
        available_MW:
          type: integer
          description: Available Megawatts for the System Controller to Dispatch (in MW)
          format: int32
        dispatched?:
          type: string
          description: Dispatched MW indicator - either 'Y' for Yes or 'N' for No
        dispatched_MW:
          type: integer
          description: Dispatched Megawatts (in MW)
          format: int32
        flexible?:
          type: string
          description: Flexible block indicator -'Y' indicates that the System Controller is able to partially dispatch the block, 'N' indicates they can not
        offer_control:
          type: string
          description: Offer Control - Offer control parties separated by a semi-colon
    EnergyMeritOrderReport:
      type: object
      properties:
        data:
          type: array
          items:
            $ref: '#/components/schemas/MeritOrderData'
    MeritOrderEnergyGetRequest:
      pattern: ^\d{4}\-(0[1-9]|1[012])\-(0[1-9]|[12][0-9]|3[01])$
      type: string
      x-apim-inline: true
  securitySchemes:
    apiKeyHeader:
      type: apiKey
      name: API-KEY
      in: header
    apiKeyQuery:
      type: apiKey
      name: subscription-key
      in: query
x-provenance:
  harvestedBy: API Evangelist
  harvestedOn: '2026-07-27'
  sourcePortal: https://developer-apim.aeso.ca/
  method: Assembled verbatim from the AESO Azure API Management developer-portal data API, which is served anonymously. AESO's own OpenAPI export (?export=true&format=openapi) returns a valid document with an EMPTY paths object, so paths, parameters, responses, examples and component schemas were read from the portal's operations/ and schemas/ endpoints and reassembled without alteration. Nothing was invented.
  sources:
  - url: https://developer-apim.aeso.ca/developer/apis/energymeritorder-api-v1?api-version=2022-04-01-preview
    status: 200
    note: API metadata
  - url: https://developer-apim.aeso.ca/developer/apis/energymeritorder-api-v1?export=true&format=openapi%2Bjson&api-version=2022-04-01-preview
    status: 200
    note: AESO OpenAPI export (empty paths) - basis for info/servers/security
  - url: https://developer-apim.aeso.ca/developer/apis/energymeritorder-api-v1/operations?api-version=2022-04-01-preview
    status: 200
    note: operation list
  - url: https://developer-apim.aeso.ca/developer/apis/energymeritorder-api-v1/schemas?api-version=2022-04-01-preview
    status: 200
    note: schema list
  - url: https://developer-apim.aeso.ca/developer/apis/energymeritorder-api-v1/operations/getMeritOrderReport?api-version=2022-04-01-preview
    status: 200
    note: operation detail
  - url: https://developer-apim.aeso.ca/developer/apis/energymeritorder-api-v1/schemas/675b19e43d594b1e2075ef31?api-version=2022-04-01-preview
    status: 200
    note: schema document