NOTICE DATE:  November 24, 2010

NOTICE TYPE:  M-A112410-01 General

SHORT DESCRIPTION:  Market Data Transparency Terms of Use guide for access to ERCOT extracts and reports


DAY AFFECTED:  November 24, 2010

LONG DESCRIPTION:  ERCOT publishes publicly and securely accessible market information extracts and reports on its website at regular intervals. These extracts and reports can also be accessed by Market Participants using Application Programmatic Interface (API), External Web Services (EWS) and the Market Information System (MIS). In order to maintain public access performance for these extracts and reports, ERCOT provides a “Market Data Transparency Terms of Use” guide. This document defines ERCOT’s policy related to the usage of website and/or API, EWS and MIS access to extracts and reports.

ERCOT has currently set a policy that queries or scan rates are not to exceed three times the frequency an extract or report is generated. The generating frequency of extracts and reports are listed in the ERCOT Market Information List (EMIL), located at See EMIL column E, “Generating Frequency” for information on how often each extract and report will be generated and posted by ERCOT.

This policy applies to both:

·         Automated screen scraping programs that access the ERCOT URL(s) listed in the table

The objectives of this policy are to:


Note that query submission at a faster rate will not provide additional benefits to the Market Participant.

ADDITIONAL INFORMATION:  In case of violations of this policy, ERCOT reserves the right to block the offending IP address or group of IP addresses at the Organizationally Unique Identifier (OUI) level. Further, ERCOT reserves the right to block IP addresses at the domain level, with the affect that offending systems will not be able to access any ERCOT web pages or services. The Market Participant will be unblocked once they have adjusted their queries in line with this policy.

The Market Data Transparency Terms of Use is posted under Market Data Transparency at


CONTACT:  If you have any questions related to this policy, 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 Client [log in to unmask].

For questions or clarifications related to technical issues, please contact the ERCOT Help Desk at (512) 248-3900 or via email at [log in to unmask].

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