MISO File Download API

aid: miso:miso-file-download-api
name: MISO File Download API
description: 'The bulk file-retrieval counterpart to MUI 2.0, on the same two client-certificate-gated
  hosts and documented only in a PDF. MISO''s File Download Specification lays out a consistent pair of
  operations per report family — GET /portalDownload/{type}/files to list what is available and GET /portalDownload/{type}/file
  to retrieve one — across at least nine types: day-ahead schedule reports (dasr), electric quarterly
  reports (eqr), exposure, invoices, market clearing and market results (mcmr), market operations control
  reports (mocr), resource load and adjustment (rla) and settlement statement information (ssi), each
  with its own query parameters for entity, date, asset owner, market type and output format. Production
  is https://markets.midwestiso.org/portalDownload and the customer-facing test environment is https://cce.midwestiso.org/portalDownload.
  Access is gated exactly as MUI 2.0 is: an anonymous TLS connection to either host on 2026-08-06 failed
  at the handshake with an SSL alert rather than returning any HTTP status, which is direct evidence of
  mutual-TLS client-certificate enforcement. NO MACHINE-READABLE CONTRACT IS PUBLISHED FOR THIS API and
  none could be harvested. MISO does publish one for MUI 2.0, at cdn.misoenergy.org, so the capability
  plainly exists — it was simply never done for this surface. The 145KB specification PDF is the only
  description of it that exists.'
humanURL: https://cdn.misoenergy.org/MISO%20-%20File%20Download%20Specification424459.pdf
baseURL: https://markets.midwestiso.org/portalDownload
tags:
- Energy Markets
- Market Participants
- Bulk Download
- Settlement
- Invoices
- Client Certificate
tags_raw:
- Energy Markets
- Market Participants
- Bulk Download
- Settlements
- Invoices
- Client Certificate
properties:
- type: Documentation
  url: https://cdn.misoenergy.org/MISO%20-%20File%20Download%20Specification424459.pdf
- type: Onboarding
  url: https://www.misoenergy.org/markets-and-operations/mp-registration/market-participation/
x-coverage:
  state: gated
  reason: no-machine-readable-spec
  detail: 'Documented in a PDF and nowhere else. Searched for a published contract on 2026-08-06 and found
    none: the Wayback CDX index for cdn.misoenergy.org holds no .yaml or .json capture other than three
    .well-known probes that 404''d in 2023, and filtering every archived URL for misoenergy.org, www.misoenergy.org,
    api.misoenergy.org, cce.midwestiso.org and markets.midwestiso.org on swagger / openapi / .yaml / .yml
    / api-docs returns nothing on any host, ever. The MUI 2.0 yaml on the same CDN was still live and
    514KB on the same day, so the CDN does serve specs. Recorded as a documented but uncontracted surface
    rather than reconstructed from the PDF — a spec written from documentation by someone who has never
    called the API would carry MISO''s name over inferred error responses and schemas.'
  raised_by: A reader, 2026-08-05, who asked for an OpenAPI and was told why we will not author one.
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg