Upon successful login, the Margin Service API will return a session ID in the
sessionId HTTP response header.
When API activity is performed utilizing a CME Group Login ID, this activity can be seen by logging into the CME CORE UI with the CME Group Login ID.
Entitlement for API calls are determined by the CME Group Login ID or API ID used for authentication .Entitlement is consistent for users between the Margin Service API and user interface. For instance, if a CME CORE user has the ability to calculate margin of an interest rate swap in CME CORE, the user will be able to perform the same function through and by completing a standard API license with CME. To create a new API ID, create a login at
Entitlements are provisioned by CME CORE system administrators. Entitlement management is not available through the Margin Service API.