IESO
The Independent Electricity System Operator (IESO) is the Crown corporation that operates Ontario's bulk electricity system and administers the province's wholesale electricity market, balancing supply and demand in real time, running the day-ahead and real-time energy and operating reserve markets, procuring capacity and transmission rights, planning the provincial grid, and delivering the Save on Energy conservation programs. It sits at the top of Canada's largest provincial electricity value chain — upstream of the licensed local distribution companies that bill retail customers — which is why its API posture splits cleanly in two. Its market and system data surface is genuinely open: a public report repository at reports-public.ieso.ca serves 139 report directories of demand, price, generation-by-fuel, intertie flow, outage, adequacy and settlement data as CSV, XML and XLSX over anonymous HTTPS with no account, key or registration, backed by published XSD schemas and a public interface specification. Its programmatic APIs are the opposite: the Axway SecureTransport REST API at reports.ieso.ca/api/v1.4, the SOAP Market Information Management web services, and the Appian-based Online IESO registration, retrofit, dispatch and outage web services are all reserved for registered Ontario market participants with IESO-issued machine accounts. IESO publishes no consumer energy-data API: Ontario's Green Button mandate (O. Reg. 633/21) binds licensed electricity and gas distributors, not the system operator, so there is no retail usage or billing surface here at all.
IESO publishes 9 APIs on the APIs.io network. Tagged areas include Energy, Canada, Electricity, Energy Markets, and Grid.
The IESO catalog on APIs.io includes 1 event-driven AsyncAPI specification.
IESO’s developer surface includes documentation, API reference, support, signup flow, engineering blog, authentication, changelog, and 27 more developer resources.
9 APIs
1 MCP Servers
EnergyCanadaElectricityEnergy MarketsGridSystem OperatorMarket DataOpen DataOntarioDemand ResponseRenewables
Individual APIs this provider publishes, each with its own machine-readable definition.
Model Context Protocol servers that expose these APIs to AI agents.
AsyncAPI definitions for this provider's event-driven and streaming APIs.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
OAuth scopes governing access to this provider's APIs.
aid: ieso
url: https://raw.githubusercontent.com/api-evangelist/ieso/refs/heads/main/apis.yml
name: IESO
kind: company
description: 'The Independent Electricity System Operator (IESO) is the Crown corporation that operates Ontario''s bulk electricity
system and administers the province''s wholesale electricity market, balancing supply and demand in real time, running the
day-ahead and real-time energy and operating reserve markets, procuring capacity and transmission rights, planning the provincial
grid, and delivering the Save on Energy conservation programs. It sits at the top of Canada''s largest provincial electricity
value chain — upstream of the licensed local distribution companies that bill retail customers — which is why its API posture
splits cleanly in two. Its market and system data surface is genuinely open: a public report repository at reports-public.ieso.ca
serves 139 report directories of demand, price, generation-by-fuel, intertie flow, outage, adequacy and settlement data
as CSV, XML and XLSX over anonymous HTTPS with no account, key or registration, backed by published XSD schemas and a public
interface specification. Its programmatic APIs are the opposite: the Axway SecureTransport REST API at reports.ieso.ca/api/v1.4,
the SOAP Market Information Management web services, and the Appian-based Online IESO registration, retrofit, dispatch and
outage web services are all reserved for registered Ontario market participants with IESO-issued machine accounts. IESO
publishes no consumer energy-data API: Ontario''s Green Button mandate (O. Reg. 633/21) binds licensed electricity and gas
distributors, not the system operator, so there is no retail usage or billing surface here at all.'
image: https://www.ieso.ca/-/media/Images/IESO/Logo/ieso-logo-lrg.png
tags:
- Energy
- Canada
- Electricity
- Energy Markets
- Grid
- System Operator
- Market Data
- Open Data
- Ontario
- Demand Response
- Renewables
created: '2026-07-27'
modified: '2026-07-27'
specificationVersion: '0.23'
apis:
- aid: ieso:ieso-public-reports-repository
name: IESO Public Reports Repository
description: The IESO's open market and system data surface. A flat HTTPS file repository publishing 139 report directories
— hourly Ontario and market demand, HOEP and nodal/zonal prices, day-ahead and pre-dispatch LMPs, generator output and
capability, generation by fuel type, intertie schedules and flows, transmission and generation outages, operating reserve,
adequacy, transmission rights auction results and settlement uplift — as CSV, XML and XLSX. Report URLs follow a documented,
stable pattern (https://reports-public.ieso.ca/public/<Document Identifier>/PUB_<Report>_<date>_v<n>.<ext>) and are readable
anonymously with no account, API key, registration or licence acceptance. Verified HTTP 200 on the root listing and on
a live data file on 2026-07-27. This is not a REST API — there are no query parameters, filtering, pagination or content
negotiation — but it is a documented, machine-readable, schema-backed retrieval interface intended for automation, described
in IESO's own Outbound Automated Document specification (IMO_SPEC_0100).
humanURL: https://www.ieso.ca/en/Power-Data/Data-Directory
baseURL: https://reports-public.ieso.ca/public/
tags:
- Market Data
- Open Data
- Electricity
- Reports
- Ontario
properties:
- type: Documentation
url: https://www.ieso.ca/en/Power-Data/Data-Directory
- type: Documentation
url: https://www.ieso.ca/en/Power-Data
- type: Specification
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/xml-automated-docs/IMO_SPEC_0100.pdf
- type: Specification
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/xml-automated-docs/STD-2.pdf
- type: XSD
url: xsd/ieso-imo-document-r1.xsd
- type: XSD
url: xsd/ieso-document-r1.xsd
- type: XSD
url: xsd/ieso-intertie-schedule-flow-r1.xsd
- type: XSD
url: xsd/ieso-gen-output-capability-r1.xsd
- type: XSD
url: xsd/ieso-disp-uncons-hoep-r1.xsd
- type: XSD
url: xsd/ieso-disp-advisory-r1.xsd
- type: XSD
url: xsd/ieso-dacp-predisp-energy-r1.xsd
- type: XSD
url: xsd/ieso-dacp-predisp-prices-r1.xsd
- type: XSD
url: xsd/ieso-dacp-adequacy-r1.xsd
- type: XSD
url: xsd/ieso-dacp-reliability-commit-r1.xsd
- type: XSD
url: xsd/ieso-dacp-commit-r1.xsd
- type: XSD
url: xsd/ieso-dacp-check-source-ade-r1.xsd
- type: XSD
url: xsd/ieso-financial-binding-status-r1.xsd
- type: Sandbox
url: https://reports-public-sandbox.ieso.ca/public/
- type: DataModel
url: data-model/ieso-data-model.yml
- aid: ieso:ieso-reports-site-rest-api
name: IESO Reports Site REST API
description: 'A RESTful file-access API provided by Axway SecureTransport, used to automate retrieval of reports from the
IESO Reports Site. Accepts and returns both JSON and XML, and exposes file and directory listing (GET /files, GET /files/{path}),
file property inspection (?status) and file download, with limit, sortBy and order parameters. Every request must carry
the query string parameter ?idp_id=ieso and HTTP Basic credentials. IESO documents this endpoint only for the CONFIDENTIAL
participant report repository — the guide states plainly that "the recommended programmatic access applies to confidential
reports repository and not public reports". Credentials are IESO-issued machine accounts granted to registered Ontario
market participants on request; there is no self-serve signup. Probed anonymously on 2026-07-27: https://reports.ieso.ca/api/v1.4/files?idp_id=ieso
returned HTTP 401, and the sandbox at reports-sandbox.ieso.ca returned HTTP 401. The same path on the public host (reports-public.ieso.ca)
returned HTTP 404 — the open data is not served through this API.'
humanURL: https://www.ieso.ca/sector-participants/technical-interfaces
baseURL: https://reports.ieso.ca/api/v1.4
tags:
- Reports
- File Transfer
- Market Participants
- REST
properties:
- type: Documentation
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/api-reports-guide/IESO_Reports_API_Guide.pdf
- type: Specification
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/xml-automated-docs/IMO_SPEC_0100.pdf
- type: Documentation
url: https://www.ieso.ca/sector-participants/technical-interfaces
- aid: ieso:ieso-mim-web-services
name: IESO Market Information Management (MIM) Web Services
description: SOAP web services that let registered Ontario market participants submit and retrieve market information programmatically.
The published WSDL (service name emim-web-service, target namespace http://webservices.ieso.ca/emim/) declares 23 operations
covering real-time energy bid upload, query and cancel, operating reserve bids, schedule bids, bilateral contract bids,
daily dispatch data, forebay data, resource and market status queries, market messages, an act-as-market-participant operation
and a health check. Access requires an IESO UserID and password (formatted user@participantName) plus source IP whitelisting
and a client truststore; IESO documents a sandbox endpoint at https://webservices-sandbox.ieso.ca/emim. Neither the production
host (webservices.ieso.ca) nor the sandbox host resolved or connected from the open internet on 2026-07-27 (curl exit
code 000), consistent with network-level restriction to whitelisted participants. The WSDL and its schema are, however,
downloadable anonymously from ieso.ca and are harvested here verbatim.
humanURL: https://www.ieso.ca/sector-participants/technical-interfaces
baseURL: https://webservices.ieso.ca/emim
tags:
- SOAP
- Bids and Offers
- Market Participants
- Energy Markets
properties:
- type: WSDL
url: wsdl/ieso-mim-web-services.wsdl
- type: XSD
url: xsd/ieso-mim-web-services.xsd
- type: Documentation
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/mp-submissions/MWT-User-Guide.pdf
- type: Examples
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/mp-submissions/MIM-sample-request-response.zip
- type: SDK
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/mp-submissions/MIM%20Web%20Services%20Toolkit%20-%20MWT.zip
- type: Sandbox
url: https://webservices-sandbox.ieso.ca/emim
- type: AgentSkill
url: skills/ieso-mim-bid-submission.md
- aid: ieso:ieso-registration-facilities-api
name: IESO Registration System Facilities API
description: 'A REST API on the Appian-based Online IESO platform for retrieving and maintaining facility registration data.
SPEC-249 documents the base path https://online.ieso.ca/suite/webapi/ and the facilities resource at https://online.ieso.ca/suite/webapi/reg-v1-facilities/,
with a sandbox at https://onlinesandbox.ieso.ca/suite/webapi/. Authentication is by Appian API key, supplied three ways
— HTTP Basic with the key as username-and-blank-password (or the reverse), an Appian-API-Key header, or an Authorization
Bearer header — over mandatory HTTPS; a missing or invalid Authorization header returns 401. There is no self-serve key
issuance: the organization''s registered IESO Rights Administrator must request an API machine account with "Registration
API" access, so this is a market-participant-only surface.'
humanURL: https://www.ieso.ca/sector-participants/technical-interfaces
baseURL: https://online.ieso.ca/suite/webapi/reg-v1-facilities
tags:
- Registration
- Facilities
- Market Participants
- REST
properties:
- type: Documentation
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/registration-system/FacilityAPISpecification-SPEC-249.pdf
- type: Documentation
url: https://www.ieso.ca/sector-participants/technical-interfaces
- aid: ieso:ieso-retrofit-api
name: IESO Retrofit System API
description: A web service API for the Retrofit program under Save on Energy, IESO's conservation and demand management
portfolio, allowing participants to integrate with the Retrofit application and project workflow. SPEC-188 documents it
on the same Online IESO Appian platform (https://online.ieso.ca/suite/webapi/) using API-key authentication via HTTP Basic,
an Appian-API-Key header, or a Bearer token. Access requires an IESO-issued API machine account; there is no public signup
and no anonymous endpoint.
humanURL: https://www.ieso.ca/sector-participants/technical-interfaces
baseURL: https://online.ieso.ca/suite/webapi
tags:
- Energy Efficiency
- Demand Response
- Retrofit
- REST
properties:
- type: Documentation
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/retrofit-system/RetrofitAPI-SPEC-188.pdf
- type: Documentation
url: https://www.ieso.ca/sector-participants/technical-interfaces
- aid: ieso:ieso-retrofit-service-provider-api
name: IESO Retrofit Service Provider API
description: A companion web service API documented in SPEC-232 for service providers participating in the Save on Energy
Retrofit program, covering the service-provider side of project submission and management on the Online IESO platform.
Participant-only; requires an IESO-issued API account. No public self-serve credential issuance is published. SPEC-232
documents the Appian root endpoint https://online.ieso.ca/suite/webapi/ with eight rft-sp-v1-* resource suffixes (applications,
appdetails, appdoc, appcomments, facilities, facdetails, facdoc, persons), GET/PUT/POST/DELETE methods, API-key authentication
in three forms, and the only published HTTP status code table in the IESO estate (200, 201, 400, 401, 403, 404, 408, 429).
The sandbox and production root endpoint values are themselves redacted to "URL value" in the public PDF.
humanURL: https://www.ieso.ca/sector-participants/technical-interfaces
baseURL: https://online.ieso.ca/suite/webapi
tags:
- Energy Efficiency
- Service Providers
- Retrofit
properties:
- type: Documentation
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/retrofit-system/RetrofitServiceProviderAPI-SPEC-232.pdf
- type: Documentation
url: https://www.ieso.ca/sector-participants/technical-interfaces
- aid: ieso:ieso-dispatch-service-web-service
name: IESO Dispatch Service Web Service
description: A web service, specified in SPEC-154, through which registered market participants retrieve dispatch instructions
issued by the IESO and send back acknowledgements and responses. This is the machine interface to real-time dispatch of
Ontario's grid. The design specification is published openly as a PDF, but no base URL is disclosed in it and access is
restricted to registered market participants operating dispatchable facilities.
humanURL: https://www.ieso.ca/sector-participants/technical-interfaces
tags:
- Dispatch
- Real-Time
- Market Participants
tags_raw:
- Dispatch
- Real Time
- Market Participants
properties:
- type: Documentation
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/dispatch-service-system/SPEC-154-Dispatch-Service-Web-Service-Design-Specifications.pdf
- type: Documentation
url: https://www.ieso.ca/sector-participants/technical-interfaces
- aid: ieso:ieso-dispatch-notification-service
name: IESO Dispatch Notification Service Web Service
description: A push-notification web service, specified in SPEC-155, that delivers automated notifications of dispatch instructions
to registered market participants rather than requiring them to poll. The design specification is published openly; the
endpoint and credentials are issued only to registered market participants.
humanURL: https://www.ieso.ca/sector-participants/technical-interfaces
tags:
- Dispatch
- Notification
- Push
- Market Participants
tags_raw:
- Dispatch
- Notifications
- Push
- Market Participants
properties:
- type: Documentation
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/dispatch-service-system/SPEC-155-Dispatch-Notification-Service-Web-Service-Design-Specifications.pdf
- type: Documentation
url: https://www.ieso.ca/sector-participants/technical-interfaces
- type: Webhooks
url: asyncapi/ieso-dispatch-notification-webhooks.yml
- type: AgentSkill
url: skills/ieso-dispatch-notification-receiver.md
- aid: ieso:ieso-ocss-web-service
name: IESO Outage Coordination and Scheduling System (OCSS) Web Service
description: A web service, specified in SPEC-113, for submitting and managing transmission and generation outage requests
in IESO's Outage Coordination and Scheduling System. The design specification is public; the service itself is restricted
to registered market participants. Note that the resulting outage data is republished anonymously through the public report
repository (TxOutages* and TxOutagesTodayAll directories) — the write side is gated, the read side is open.
humanURL: https://www.ieso.ca/sector-participants/technical-interfaces
tags:
- Outages
- Scheduling
- Transmission
- Market Participants
properties:
- type: Documentation
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/outage-management/WebServiceDesignSpec_SPEC-113.pdf
- type: Documentation
url: https://www.ieso.ca/sector-participants/technical-interfaces
common:
- type: Website
url: https://www.ieso.ca/
- type: DeveloperPortal
url: https://www.ieso.ca/sector-participants/technical-interfaces
- type: Documentation
url: https://www.ieso.ca/sector-participants/technical-interfaces
- type: Documentation
url: https://www.ieso.ca/en/Power-Data/Data-Directory
- type: APIReference
url: https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/xml-automated-docs/IMO_SPEC_0100.pdf
- type: Support
url: https://www.ieso.ca/Corporate-IESO/Contact
- type: SignUp
url: https://www.ieso.ca/Sector-Participants/Connection-Process/Overview
- type: Login
url: https://online.ieso.ca/
- type: Roadmap
url: https://www.ieso.ca/sector-participants/change-management/it-release-schedule
- type: Deprecation
url: https://www.ieso.ca/sector-participants/change-management/it-release-schedule
- type: TermsOfService
url: https://www.ieso.ca/Terms-of-Use
- type: PrivacyPolicy
url: https://www.ieso.ca/privacy
- type: Security
url: https://www.ieso.ca/Sector-Participants/Cyber-Security/Cyber-Security-Incident-Reporting
- type: Blog
url: https://www.ieso.ca/en/Corporate-IESO/Blog
- type: LinkedIn
url: https://www.linkedin.com/company/ieso
- type: Email
url: mailto:customer.relations@ieso.ca
- type: Authentication
url: authentication/ieso-authentication.yml
- type: OAuthScopes
url: scopes/ieso-scopes.yml
- type: Conventions
url: conventions/ieso-conventions.yml
- type: ErrorCatalog
url: errors/ieso-error-codes.yml
- type: DataModel
url: data-model/ieso-data-model.yml
- type: Lifecycle
url: lifecycle/ieso-lifecycle.yml
- type: ChangeLog
url: changelog/ieso-changelog.yml
- type: Sandbox
url: sandbox/ieso-sandbox.yml
- type: Conformance
url: conformance/ieso-conformance.yml
- type: Packages
url: packages/ieso-packages.yml
- type: SDKs
url: packages/ieso-packages.yml
- type: Webhooks
url: asyncapi/ieso-dispatch-notification-webhooks.yml
- type: WellKnown
url: well-known/ieso-well-known.yml
- type: MCPServer
url: mcp/ieso-mcp.yml
- type: AgentSkill
url: skills/_index.yml
- type: LLMsTxt
url: llms/ieso-llms.txt
- type: DomainSecurity
url: security/ieso-domain-security.yml
- type: VulnerabilityDisclosure
url: security/ieso-vulnerability-disclosure.yml
maintainers:
- FN: Kin Lane
email: kin@apievangelist.com
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