Technical Reference Materials

API Technical Specifications for Dispatch Services and MIM

As part of the Market Renewal Program (MRP), changes are being made to the way Market Participants will interact with the Market Information Management and the Dispatch Services systems. These applications are currently used by dispatchable Market Participants to submit bids and offers for the physical market and to receive dispatch instructions from the IESO. To prepare Market Participants, the IESO has provided an updated set of API technical specifications, schema and sample files in the section below. Further details on the updated materials are noted in the Participant Readiness Memo.

Market Information Management System

Dispatch Service System

IESO Reports Impacted by MRP

The changes to come from the Market Renewal Program (MRP) will introduce new reports and update existing reports to reflect the renewed market. These changes will apply to both public and confidential reports. The complete list of market facing reports impacted by MRP can be downloaded and includes target timing for posting schema and sample files. To assist market participants in preparing for these changes, the IESO is publishing the schema, sample and help files for the new and revised IESO reports. Market participants are recommended to verify that they can view and download these reports, and confirm that the structural changes in these files can be accepted by their internal processes and systems before MRP Go-Live. The table below provides a list of schema, sample, and help files so far that market participants can view and download for market facing reports. Please note that the timing for posting schema, sample, and help files for market facing reports are subject to change.

Complete list of market facing reports impacted by MRP** (updated as of March 27, 2024)

Reason for Update

As of March 27, 2024, the complete list of market facing reports impacted by MRP has been updated. The following changes were made:

  • A new report titled “Intertie Economic Withholding Monthly Summary Report” has been added. The schema, sample, and help files for this report is scheduled for delivery in Q1 2024.
  • The report audience for both the Day-Ahead Market Financial Reference Level Report and the Real-Time Market Financial Reference Level Report has changed from Public to Market Participant Confidential.
  • The Realtime Operating Reserve Bid Offer Report was identified for no change in detail design. During implementation, it was found that the content for this report will be revised, and the report will be renamed as Realtime Market Operating Reserve Offer Report.
  • A new report has been added to the list: Day-Ahead Market Operating Reserve Offer Report.  The schema, sample, and help files for this report will be delivered in Q2 2024.
  • Changed names of various reports for consistency with their reference in other documents.

Report Group

Target Posting

Market Power Mitigation

Q4 2023

Day-Ahead Market Scheduling and Operating Reserve


Pre-Dispatch Scheduling and Operating Reserve

Q1/Q2 2024

Real-Time Scheduling and Operating Reserve


Q2 2024

Market Inputs

Q2 2024


No schema changes, only timing changes


Q2 2024


Q2 2024

Transmission (Tx) Constraints

No schema changes, only timing changes

Transmission Rights

Q2 2024

Day-Ahead Market Pricing


Pre-Dispatch Pricing

Q4 2023/Q1 2024

Real-Time Pricing



Q2 2024


Q2 2024

**Table last updated March 27, 2024, timelines subject to change.