openapi: 3.2.0
info:
  title: MISO Public Interchange 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: Interchange
paths:
  /api/Interchange/GetNai:
    get:
      operationId: getInterchangeGetNai
      summary: Tie Flow / Net Actual Interchange (NAI) — GetNai
      description: Source data behind the MISO public "Tie Flow / Net Actual Interchange (NAI)" 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:
                  Date:
                    type: string
                  Actual:
                    type: object
                    properties:
                      HourandMin:
                        type: string
                      TieFlow:
                        type: object
                        properties:
                          Name:
                            type: string
                          Value:
                            type: string
              example:
                Date: 27-Jul-2026 - Interval 08:10 EST
                Actual:
                  HourandMin: 08:10
                  TieFlow:
                    Name: MISO
                    Value: '-5495.34'
      tags:
      - Interchange
  /api/Interchange/GetNai/FiveMinute:
    get:
      operationId: getInterchangeGetNaiFiveMinute
      summary: Tie Flow / Net Actual Interchange (NAI) — FiveMinute
      description: Source data behind the MISO public "Tie Flow / Net Actual Interchange (NAI)" 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: array
                items:
                  type: object
                  properties:
                    Time:
                      type: string
                    Value:
                      type: string
              example:
              - Time: 2026-07-26 8:15:00 AM
                Value: '-5573.87'
              - Time: 2026-07-26 8:20:00 AM
                Value: '-5321.07'
      tags:
      - Interchange
  /api/Interchange/GetNai/Imports:
    get:
      operationId: getInterchangeGetNaiImports
      summary: Net Actual Interchange (Imports)
      description: Source data behind the MISO public "Net Actual Interchange (Imports)" 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: array
                items:
                  type: object
                  properties:
                    Time:
                      type: string
                    Value:
                      type: string
              example:
              - Time: 2026-07-26 1:15:00 PM
                Value: '-5572.00'
              - Time: 2026-07-26 1:20:00 PM
                Value: '-5319.00'
      tags:
      - Interchange
  /api/Interchange/GetNsi:
    get:
      operationId: getInterchangeGetNsi
      summary: Net Scheduled Interchange — GetNsi
      description: Source data behind the MISO public "Net Scheduled Interchange" 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:
                  instance:
                    type: array
                    items:
                      type: object
                      properties:
                        timestamp:
                          type: string
                        AECI:
                          type: string
                        LGEE:
                          type: string
                        MHEB:
                          type: string
                        MISO:
                          type: string
                        ONT:
                          type: string
                        PJM:
                          type: string
                        SOCO:
                          type: string
                        SPA:
                          type: string
                        SWPP:
                          type: string
                        TVA:
                          type: string
                  RefId:
                    type: string
                  MktDay: {}
              example:
                instance:
                - timestamp: '2026-07-27 08:08:00'
                  AECI: '-164'
                  LGEE: '179'
                  MHEB: '-2061'
                  MISO: '-5425'
                  ONT: '-207'
                  PJM: '-3151'
                  SOCO: '138'
                  SPA: '-6'
                  SWPP: '-78'
                  TVA: '16'
                RefId: 27-Jul-2026 - Interval 08:08 EST
                MktDay: null
      tags:
      - Interchange
  /api/Interchange/GetNsi/FiveMinute:
    get:
      operationId: getInterchangeGetNsiFiveMinute
      summary: Net Scheduled Interchange — FiveMinute
      description: Source data behind the MISO public "Net Scheduled Interchange" 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:
                  instance:
                    type: array
                    items:
                      type: object
                      properties:
                        timestamp:
                          type: string
                        AECI:
                          type: string
                        LGEE:
                          type: string
                        MHEB:
                          type: string
                        MISO:
                          type: string
                        ONT:
                          type: string
                        PJM:
                          type: string
                        SOCO:
                          type: string
                        SPA:
                          type: string
                        SWPP:
                          type: string
                        TVA:
                          type: string
                  RefId:
                    type: string
                  MktDay: {}
              example:
                instance:
                - timestamp: '2026-07-25 19:05:00'
                  AECI: '220'
                  LGEE: '-75'
                  MHEB: '-1737'
                  MISO: '-6906'
                  ONT: '-1540'
                  PJM: '-3540'
                  SOCO: '172'
                  SPA: '-93'
                  SWPP: '-196'
                  TVA: '-370'
                - timestamp: '2026-07-25 19:10:00'
                  AECI: '220'
                  LGEE: '-75'
                  MHEB: '-1737'
                  MISO: '-6906'
                  ONT: '-1540'
                  PJM: '-3540'
                  SOCO: '172'
                  SPA: '-93'
                  SWPP: '-196'
                  TVA: '-370'
                RefId: 27-Jul-2026 - Interval 08:08 EST
                MktDay: null
      tags:
      - Interchange
  /api/Interchange/GetNsi/MISO:
    get:
      operationId: getInterchangeGetNsiMISO
      summary: Net Scheduled Interchange (MISO) — MISO
      description: Source data behind the MISO public "Net Scheduled Interchange (MISO)" 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:
                  instance:
                    type: array
                    items:
                      type: object
                      properties:
                        timestamp:
                          type: string
                        NSI:
                          type: string
                  RefId:
                    type: string
                  MktDay: {}
              example:
                instance:
                - timestamp: '2026-07-27 08:13:00'
                  NSI: '-5405'
                RefId: 27-Jul-2026 - Interval 08:13 EST
                MktDay: null
      tags:
      - Interchange
  /api/Interchange/GetNsi/MISOFiveMinute:
    get:
      operationId: getInterchangeGetNsiMISOFiveMinute
      summary: Net Scheduled Interchange (MISO) — MISOFiveMinute
      description: Source data behind the MISO public "Net Scheduled Interchange (MISO)" 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:
                  instance:
                    type: array
                    items:
                      type: object
                      properties:
                        timestamp:
                          type: string
                        NSI:
                          type: string
                  RefId:
                    type: string
                  MktDay: {}
              example:
                instance:
                - timestamp: '2026-07-26 08:20:00'
                  NSI: '-5325'
                - timestamp: '2026-07-26 08:25:00'
                  NSI: '-5325'
                RefId: 27-Jul-2026 - Interval 08:13 EST
                MktDay: null
      tags:
      - Interchange
  /api/Interchange/GetNsi/MISOOneMinute:
    get:
      operationId: getInterchangeGetNsiMISOOneMinute
      summary: Net Scheduled Interchange (MISO) — MISOOneMinute
      description: Source data behind the MISO public "Net Scheduled Interchange (MISO)" 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:
                  instance:
                    type: array
                    items:
                      type: object
                      properties:
                        timestamp:
                          type: string
                        NSI:
                          type: string
                  RefId:
                    type: string
                  MktDay: {}
              example:
                instance:
                - timestamp: '2026-07-25 19:01:00'
                  NSI: '-6639'
                - timestamp: '2026-07-25 19:02:00'
                  NSI: '-6706'
                RefId: 27-Jul-2026 - Interval 08:08 EST
                MktDay: null
      tags:
      - Interchange
  /api/Interchange/GetNsi/OneMinute:
    get:
      operationId: getInterchangeGetNsiOneMinute
      summary: Net Scheduled Interchange — OneMinute
      description: Source data behind the MISO public "Net Scheduled Interchange" 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:
                  instance:
                    type: array
                    items:
                      type: object
                      properties:
                        timestamp:
                          type: string
                        AECI:
                          type: string
                        LGEE:
                          type: string
                        MHEB:
                          type: string
                        MISO:
                          type: string
                        ONT:
                          type: string
                        PJM:
                          type: string
                        SOCO:
                          type: string
                        SPA:
                          type: string
                        SWPP:
                          type: string
                        TVA:
                          type: string
                  RefId:
                    type: string
                  MktDay: {}
              example:
                instance:
                - timestamp: '2026-07-25 19:01:00'
                  AECI: '182'
                  LGEE: '-73'
                  MHEB: '-1733'
                  MISO: '-6639'
                  ONT: '-1543'
                  PJM: '-3264'
                  SOCO: '172'
                  SPA: '-114'
                  SWPP: '-148'
                  TVA: '-370'
                - timestamp: '2026-07-25 19:02:00'
                  AECI: '191'
                  LGEE: '-74'
                  MHEB: '-1734'
                  MISO: '-6706'
                  ONT: '-1542'
                  PJM: '-3333'
                  SOCO: '172'
                  SPA: '-109'
                  SWPP: '-160'
                  TVA: '-370'
                RefId: 27-Jul-2026 - Interval 08:08 EST
                MktDay: null
      tags:
      - Interchange