IESO

IESO Market Information Management (MIM) Web Services

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.

GitHub

Documentation

📖
Documentation
https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/mp-submissions/MWT-User-Guide.pdf

SDKs

📦
SDK
https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/mp-submissions/MIM%20Web%20Services%20Toolkit%20-%20MWT.zip

Other Resources

🔗
WSDL
https://raw.githubusercontent.com/api-evangelist/ieso/refs/heads/main/wsdl/ieso-mim-web-services.wsdl
🔗
XSD
https://raw.githubusercontent.com/api-evangelist/ieso/refs/heads/main/xsd/ieso-mim-web-services.xsd
🔗
Examples
https://www.ieso.ca/-/media/Files/IESO/technical-interfaces/mp-submissions/MIM-sample-request-response.zip
🔗
Sandbox
https://webservices-sandbox.ieso.ca/emim
🔗
AgentSkill
https://raw.githubusercontent.com/api-evangelist/ieso/refs/heads/main/skills/ieso-mim-bid-submission.md

API entry from apis.yml

apis.yml Raw ↑ 
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