ISO New England Inc. is the independent, nonprofit regional transmission organization authorized by the Federal Energy Regulatory Commission to operate the high-voltage power system, administer the wholesale electricity markets, and plan the power system for Connecticut, Rhode Island, Massachusetts, Vermont, New Hampshire, and most of Maine. Home market is the United States. It sits at the wholesale layer of the value chain, between generators, transmission owners, interconnections with New York and Canada, and the load-serving entities that resell power to retail customers - and it states on its own site that handling retail electricity is something it does not do. Its API posture is the sector's classic split, read from the wholesale end. Market and system data is genuinely open, so open that the ISO Express portal serves full nodal day-ahead LMP files as anonymous CSV and the public dashboards are backed by an anonymous JSON feed. Consumer data does not exist here at all, and cannot, because ISO New England holds no retail customer relationships and no Green Button, ESPI, or consumer data-portability mandate reaches it. The one documented programmatic contract, the Web Services API v1.1, is a real, richly documented RESTful surface of 477 path templates across 90 market and operations resources, but it answers 401 to anonymous callers - a developer must first create a free, self-serve ISO Express account, which the ISO says automatically grants access to the data feeds, and then authenticate with HTTP Basic over SSL.
ISO New England publishes 1 API on the APIs.io network: Web Services API v1.1. Tagged areas include Energy, United States, Electricity, Energy Markets, and Grid.
ISO New England’s developer surface includes authentication, code examples, changelog, developer portal, API reference, documentation, signup flow, and 36 more developer resources.
Regulatory Posture applies to this provider. Its tags matched the
Energy & Utilities regime, so
Regulatory Posture carries 15 points of the composite.
If this regime is wrong for your business, say so on your
provider repo — the
applicability map is public and we will correct it.
The six quality facets above are damped to 85 points between them,
because the conditional facet above carries the other
15. That is why each facet's contribution is shown against a damped
maximum: raising a quality facet moves the composite by 85% of its nominal
weight, not 100%. The full arithmetic is at apis.io/rating/.
ISO New England's RESTful interface to energy and market data, deployed November 2013 and still the current version. The public Enunciate-generated technical documentation at we...
Build a complete current picture of the New England power system - resolve the location registry, check feed freshness, then pull system load, generation fuel mix, Hub price and...
Explain a price event on a past operating day: pull the day-ahead hourly prices, the day's transmission constraints, the fuel mix and the demand-response dispatch, then correlat...
aid: iso-new-england
url: https://raw.githubusercontent.com/api-evangelist/iso-new-england/refs/heads/main/apis.yml
name: ISO New England
kind: company
description: ISO New England Inc. is the independent, nonprofit regional transmission organization authorized by the Federal
Energy Regulatory Commission to operate the high-voltage power system, administer the wholesale electricity markets, and
plan the power system for Connecticut, Rhode Island, Massachusetts, Vermont, New Hampshire, and most of Maine. Home market
is the United States. It sits at the wholesale layer of the value chain, between generators, transmission owners, interconnections
with New York and Canada, and the load-serving entities that resell power to retail customers - and it states on its own
site that handling retail electricity is something it does not do. Its API posture is the sector's classic split, read from
the wholesale end. Market and system data is genuinely open, so open that the ISO Express portal serves full nodal day-ahead
LMP files as anonymous CSV and the public dashboards are backed by an anonymous JSON feed. Consumer data does not exist
here at all, and cannot, because ISO New England holds no retail customer relationships and no Green Button, ESPI, or consumer
data-portability mandate reaches it. The one documented programmatic contract, the Web Services API v1.1, is a real, richly
documented RESTful surface of 477 path templates across 90 market and operations resources, but it answers 401 to anonymous
callers - a developer must first create a free, self-serve ISO Express account, which the ISO says automatically grants
access to the data feeds, and then authenticate with HTTP Basic over SSL.
accessModel:
pricing: free
onboarding: self-serve
trial: false
try_now: false
public: false
label: Free - Self-serve ISO Express account required for the API
confidence: high
source:
- probe
- documentation
generated: '2026-07-27'
method: observed
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/groq.png
tags:
- Energy
- United States
- Electricity
- Energy Markets
- Grid
- Open Data
- Wholesale Markets
- Demand Response
- Renewables
- New England
created: '2026-07-27'
modified: '2026-07-27'
specificationVersion: '0.23'
apis:
- aid: iso-new-england:iso-ne-web-services-api
name: ISO New England Web Services API v1.1
description: ISO New England's RESTful interface to energy and market data, deployed November 2013 and still the current
version. The public Enunciate-generated technical documentation at webservices.iso-ne.com/docs/v1.1/ publishes one page
per path template - 489 GET path templates across 91 root resources were harvested from it on 2026-07-27, of which the
overview page lists 477 - five-minute and hourly locational marginal prices, day-ahead and real-time demand, generation
fuel mix, system load, external interchange and flows, day-ahead and real-time constraints, operating reserve and reserve
prices, regulation clearing prices, Forward Capacity Market auction and reconfiguration results, FTR auction clearing
prices and results, NCPC, outages, seven-day and seven-day wind forecasts, load forecasts, power system status and conditions,
demand response dispatch and price-response events, locations, and hourly-bid participant resources. Every feed is available
in XML and JSON, selected by a .xml/.json extension on the request URL or by an Accept header. A WADL description is published
at https://webservices.iso-ne.com/api/v1.1?_wadl&_type=xml but is itself behind authentication. Authentication is HTTP
Basic over SSL; anonymous requests to the base path, to any resource, and to the WADL all return HTTP 401. Credentials
come from a free ISO Express account, which ISO New England states automatically grants access to the data feeds. Two
W3C XML Schemas describing the whole payload model are published anonymously alongside the documentation (docs/v1.1/ns0.xsd,
205 complex types, and docs/v1.1/ns1.xsd) and are saved verbatim under schemas/; the OpenAPI under openapi/ was derived
from those documents by API Evangelist, not published by ISO New England.
humanURL: https://webservices.iso-ne.com/docs/v1.1/
baseURL: https://webservices.iso-ne.com/api/v1.1
tags:
- Energy Markets
- Electricity
- Grid
- Pricing
- Demand
- Forecasting
properties:
- type: APIReference
url: https://webservices.iso-ne.com/docs/v1.1/
- type: Documentation
url: https://www.iso-ne.com/participate/support/web-services-data
- type: Documentation
url: https://www.iso-ne.com/participate/applications-status-changes/access-software-systems
- type: Documentation
url: https://www.iso-ne.com/static-assets/documents/2017/06/webservices_documentation.xlsx
- type: SignUp
url: https://www.iso-ne.com/signup
- type: Portal
url: https://www.iso-ne.com/isoexpress/
- type: OpenAPI
name: ISO New England Web Services API v1.1 (derived from the published Enunciate documentation and XSDs)
url: openapi/iso-new-england-web-services-openapi.yml
- type: XMLSchema
url: schemas/iso-new-england-web-services-ns0.xsd
- type: XMLSchema
url: schemas/iso-new-england-web-services-ns1.xsd
- type: XMLSchema
url: schemas/nextt-web-services.xsd
- type: JSONSchema
url: json-schema/iso-new-england-web-services-schemas.json
- type: Examples
url: examples/_index.yml
- type: Overlay
url: overlays/iso-new-england-web-services-overlay.yaml
- type: DataModel
url: data-model/iso-new-england-data-model.yml
- type: ErrorCatalog
url: errors/iso-new-england-problem-types.yml
- type: MCPServer
url: mcp/iso-new-england-mcp.yml
- type: WADL
url: https://webservices.iso-ne.com/api/v1.1?_wadl&_type=xml
common:
- type: AgenticAccess
url: agentic-access/iso-new-england-agentic-access.yml
- type: DomainSecurity
url: security/iso-new-england-domain-security.yml
- type: Authentication
url: authentication/iso-new-england-authentication.yml
- type: OpenAPI
name: ISO New England Web Services API v1.1 (derived)
url: openapi/iso-new-england-web-services-openapi.yml
- type: JSONSchema
url: json-schema/iso-new-england-web-services-schemas.json
- type: Examples
url: examples/_index.yml
- type: Vocabulary
url: vocabulary/iso-new-england-vocabulary.yml
- type: Conventions
url: conventions/iso-new-england-conventions.yml
- type: ErrorCatalog
url: errors/iso-new-england-problem-types.yml
- type: Lifecycle
url: lifecycle/iso-new-england-lifecycle.yml
- type: ChangeLog
url: changelog/iso-new-england-changelog.yml
- type: Conformance
url: conformance/iso-new-england-conformance.yml
- type: Compliance
name: NERC and NPCC Compliance (mandatory reliability standards - no infosec certification is published)
url: https://www.iso-ne.com/participate/rules-procedures/nerc-npcc
- type: Packages
url: packages/iso-new-england-packages.yml
- type: WellKnown
url: well-known/iso-new-england-well-known.yml
- type: MCPServer
name: Candidate MCP tool set derived from the OpenAPI (no server is published by ISO New England)
url: mcp/iso-new-england-mcp.yml
- type: DataModel
url: data-model/iso-new-england-data-model.yml
- type: Overlay
url: overlays/iso-new-england-web-services-overlay.yaml
- type: LLMsTxt
url: llms/iso-new-england-llms.txt
- type: AgentSkill
url: skills/_index.yml
- type: Arazzo
name: ISO New England grid snapshot
url: arazzo/iso-new-england-grid-snapshot.yml
- type: Arazzo
name: ISO New England price spike diagnosis
url: arazzo/iso-new-england-price-spike-diagnosis.yml
- type: Website
url: https://www.iso-ne.com/
- type: Portal
url: https://www.iso-ne.com/isoexpress/
- type: APIReference
url: https://webservices.iso-ne.com/docs/v1.1/
- type: Documentation
url: https://www.iso-ne.com/participate/support/web-services-data
- type: SignUp
url: https://www.iso-ne.com/signup
- type: Documentation
url: https://www.iso-ne.com/markets-operations/iso-express
- type: Regulation
url: https://www.iso-ne.com/markets-operations/transmission-operations-services/oasis
- type: Blog
url: https://isonewswire.com/
- type: BlogRSS
url: https://isonewswire.com/feed/
- type: LinkedIn
url: https://www.linkedin.com/company/iso-new-england/
- type: Twitter
url: https://twitter.com/isonewengland
- type: YouTube
url: https://www.youtube.com/@isonewengland
- type: GitHubOrganization
url: https://github.com/iso-ne
- type: Support
url: https://askiso.iso-ne.com/s/
- type: DeveloperPortal
url: https://www.iso-ne.com/participate/support/web-services-data
- type: GettingStarted
name: Requests to Access Software and Systems - the data-feeds access rule
url: https://www.iso-ne.com/participate/applications-status-changes/access-software-systems#data-feeds
- type: FAQ
url: https://www.iso-ne.com/participate/support/faq
- type: Glossary
url: https://www.iso-ne.com/participate/support/glossary-acronyms
- type: Roadmap
name: Key Projects - the ISO's published forward work programme
url: https://www.iso-ne.com/committees/key-projects/
- type: TermsOfService
name: Legal and Privacy (terms of use and website conditions)
url: https://www.iso-ne.com/legal-privacy
- type: PrivacyPolicy
name: Legal and Privacy (cookies and website data collection)
url: https://www.iso-ne.com/legal-privacy
maintainers:
- FN: Kin Lane
email: kin@apievangelist.com
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