NOTICE DATE: November 6, 2025
NOTICE TYPE: M-C110625-01 System Changes
SHORT DESCRIPTION: ERCOT Change to End-Point URL Address for External Web Services API in Production Environment
INTENDED AUDIENCE: All Market Participants
DAYS AFFECTED: December 4, 2025
LONG DESCRIPTION: ERCOT will be changing the External Web Services Application Programming Interface (API) end-point URL address that many Market Participants (MPs) use to access ERCOT systems with XML interface. This reconfiguration will occur at approximately midnight between December 4-5, 2025.
ERCOT will be transitioning from these External Web Services API end-point URLs:
Current Internet API URL : https://misapi.ercot.com/2007-08/Nodal/eEDS/EWS/
Current WAN API URL : https://api.wan.ercot.com:8443/2007-08/Nodal/eEDS/EWS/
To the new External Web Services API end-point URLs
New Internet API URL : https://misapi.ercot.com/NodalAPI/EWS/
New WAN API URL : https://api.wan.ercot.com/NodalAPI/EWS/
This change will affect all Market Participants that use machine-to-machine ERCOT's External Web Services API interfaces. It should be noted that this will not impact Market Participants that access the Market Information System (MIS) or other ERCOT websites through a web browser such as Market Manager User Interface (UI), Outage Scheduler UI, or Network Model Management System.
ACTION REQUIRED: Market Participants that use External Web Services API end-point URLs connectivity to ERCOT need to be prepared to reconfigure their system connections on or after midnight December 5, 2025.
ADDITIONAL INFORMATION: ERCOT is not making changes to the following security items: 1) SSL certificates used to secure the API websites, or 2) Client API certificates used for authentication to the API websites.
CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at ClientServices@ercot.com.
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dg