An ISDA Master Agreement is the standard document used to govern over-the-counter derivatives transactions. The agreement, published by the International Swaps and Derivatives Association (ISDA), outlines the terms that will be applied to a derivatives transaction between two parties, typically a derivatives dealer and counterparty.The ISDA Master Agreement itself is standard, but it comes with a customized schedule and sometimes a credit support annex, both of which are signed by the two parties in any given transaction.