generated: '2026-07-27'
method: searched
source: https://www.iso-ne.com/participate/support/web-services-data
description: >-
  ISO New England publishes no dated changelog or release-notes feed for the Web Services API. What
  it does publish are dated revision statements on the Web Services Data page and on the supporting
  documents that page links to. Those dated statements are captured verbatim below; nothing has been
  reconstructed or inferred, and the list is deliberately short because that is all the provider
  publishes.

scheme: uri-path
current_version: '1.1'
changelog_feed: null
release_notes_url: null
canonical_page: https://www.iso-ne.com/participate/support/web-services-data

entries:
- date: '2026-05'
  version: '1.1'
  type: addition
  breaking: false
  highlight: Batteries added as a Fuel Category (Rollup) parameter value.
  statement: 'Parameters and Formats for ISO Web Services - Last updated: May 2026 - Added Batteries Fuel Category (Rollup)'
  source: https://www.iso-ne.com/participate/support/web-services-data
  affects:
  - openapi/iso-new-england-web-services-openapi.yml#getGenfuelmixCurrentFuelCategoryRollupByFuelCategoryRollup
  - openapi/iso-new-england-web-services-openapi.yml#getGenfuelmixDayByDayFuelCategoryRollupByFuelCategoryRollup
  corroboration: >-
    Confirmed live on 2026-07-27 - the /genfuelmix/current feed returned a "Batteries" FuelCategory
    and FuelCategoryRollup row (see examples/iso-new-england-genfuelmix_current.json).
- date: '2025-07'
  version: '1.1'
  type: documentation
  breaking: false
  highlight: ISO Web Services Business Documentation Spreadsheet updated.
  statement: 'download the ISO Web Services Business Documentation Spreadsheet (updated July 2025)'
  source: https://www.iso-ne.com/static-assets/documents/2017/06/webservices_documentation.xlsx
  note: >-
    The linked asset path is dated 2017/06 while the page describes it as updated July 2025; both
    facts are recorded as published.
- date: '2013-11'
  version: '1.1'
  type: release
  breaking: true
  highlight: Web Services API v1.1 deployed - the current version.
  statement: 'Current version: 1.1 deployed November 2013.'
  source: https://www.iso-ne.com/participate/support/web-services-data

not_published:
- dated changelog or release-notes page for the API
- RSS/Atom feed of API changes
- per-resource version history
change_notification_channels:
- https://www.iso-ne.com/participate/support/feeds
- https://isonewswire.com/
- https://isonewswire.com/feed/