MISO Fuel Mix API

The FuelMix API from MISO — 3 operation(s) for fuelmix.

OpenAPI Specification

miso-fuelmix-api-openapi.yml Raw ↑
openapi: 3.2.0
info:
  title: MISO Public Fuel Mix API
  version: '2025-12-12'
  description: 'Real-time market and operations data displays from MISO, served from one host under /api/. Merged from two separately derived documents — Operations Displays and Markets Displays — which described the same API: same server, same (absent) authentication, and the same documentation table. Reported by a reader on 2026-08-04.'
  x-provenance:
    harvestedBy: API Evangelist
    fetchDate: '2026-07-27'
    note: 'MISO publishes no OpenAPI for its Public API. This document was assembled from MISO''s own published artifacts only: every path and every operation summary is taken verbatim from the endpoint table MISO publishes at https://public-api.misoenergy.org/ (section "Operations Displays"), and every response schema and example is derived from the live JSON MISO returned to an anonymous GET on 2026-07-27. No host, path, parameter, field name or value was invented. Examples are the real payloads with long arrays truncated to two elements. No query parameters are documented by MISO for these endpoints and none are asserted here.'
    sources:
    - https://www.misoenergy.org/markets-and-operations/RTDataAPIs/ (HTTP 200)
    - https://public-api.misoenergy.org/ (HTTP 200, endpoint table)
    - Every path in this document individually fetched anonymously; all returned HTTP 200 application/json on 2026-07-27.
servers:
- url: https://public-api.misoenergy.org
  description: MISO Public API — anonymous, no key, no account.
tags:
- name: FuelMix
paths:
  /api/FuelMix:
    get:
      operationId: getFuelMix
      summary: Fuel Mix — FuelMix
      description: Source data behind the MISO public "Fuel Mix" display. Endpoint published by MISO at https://public-api.misoenergy.org/ ; returns JSON anonymously with no key or account.
      responses:
        '200':
          description: Successful response. Verified anonymously (HTTP 200, application/json) on 2026-07-27.
          content:
            application/json:
              schema:
                type: object
                properties:
                  RefId:
                    type: string
                  TotalMW:
                    type: string
                  Fuel:
                    type: object
                    properties:
                      Type:
                        type: array
                        items:
                          type: object
                          properties:
                            INTERVALEST:
                              type: string
                            CATEGORY:
                              type: string
                            ACT:
                              type: string
                            FUEL_CATEGORY:
                              type: string
              example:
                RefId: 27-Jul-2026 - Interval 08:10 EST
                TotalMW: '96122'
                Fuel:
                  Type:
                  - INTERVALEST: 2026-07-27 8:10:00 AM
                    CATEGORY: Coal
                    ACT: '29517'
                    FUEL_CATEGORY: Coal  (29,517 MW)
                  - INTERVALEST: 2026-07-27 8:10:00 AM
                    CATEGORY: Natural Gas
                    ACT: '30223'
                    FUEL_CATEGORY: Natural Gas  (30,223 MW)
      tags:
      - FuelMix
  /api/FuelMix/Today:
    get:
      operationId: getFuelMixToday
      summary: Fuel Mix — Today
      description: Source data behind the MISO public "Fuel Mix" display. Endpoint published by MISO at https://public-api.misoenergy.org/ ; returns JSON anonymously with no key or account.
      responses:
        '200':
          description: Successful response. Verified anonymously (HTTP 200, application/json) on 2026-07-27.
          content:
            application/json:
              schema:
                type: object
                properties:
                  RefId:
                    type: string
                  TotalMW:
                    type: string
                  Fuel:
                    type: object
                    properties:
                      Type:
                        type: array
                        items:
                          type: object
                          properties:
                            INTERVALEST:
                              type: string
                            CATEGORY:
                              type: string
                            ACT:
                              type: string
                            FUEL_CATEGORY:
                              type: string
              example:
                RefId: 27-Jul-2026 - Interval 08:10 EST
                TotalMW: '0'
                Fuel:
                  Type:
                  - INTERVALEST: 2026-07-27 12:00:00 AM
                    CATEGORY: Battery Storage
                    ACT: '39'
                    FUEL_CATEGORY: Battery Storage  (39 MW)
                  - INTERVALEST: 2026-07-27 12:00:00 AM
                    CATEGORY: Coal
                    ACT: '33729'
                    FUEL_CATEGORY: Coal  (33,729 MW)
      tags:
      - FuelMix
  /api/FuelMix/Yesterday:
    get:
      operationId: getFuelMixYesterday
      summary: Fuel Mix — Yesterday
      description: Source data behind the MISO public "Fuel Mix" display. Endpoint published by MISO at https://public-api.misoenergy.org/ ; returns JSON anonymously with no key or account.
      responses:
        '200':
          description: Successful response. Verified anonymously (HTTP 200, application/json) on 2026-07-27.
          content:
            application/json:
              schema:
                type: object
                properties:
                  RefId:
                    type: string
                  TotalMW:
                    type: string
                  Fuel:
                    type: object
                    properties:
                      Type:
                        type: array
                        items:
                          type: object
                          properties:
                            INTERVALEST:
                              type: string
                            CATEGORY:
                              type: string
                            ACT:
                              type: string
                            FUEL_CATEGORY:
                              type: string
              example:
                RefId: 27-Jul-2026 - Interval 08:10 EST
                TotalMW: '0'
                Fuel:
                  Type:
                  - INTERVALEST: 2026-07-26 12:00:00 AM
                    CATEGORY: Battery Storage
                    ACT: '-234'
                    FUEL_CATEGORY: Battery Storage  (-234 MW)
                  - INTERVALEST: 2026-07-26 12:00:00 AM
                    CATEGORY: Coal
                    ACT: '29335'
                    FUEL_CATEGORY: Coal  (29,335 MW)
      tags:
      - FuelMix