Margin Service API - Onboarding and Verification

CME Group aims to provide a smooth onboarding process for clients to begin using the Margin Service API.   

During the onboarding process and with CME Group’s permission, the client may use CME Group’s testing environment to establish connectivity and verify the proper function of the API calling application.  CME Group staff works with the client throughout this process to verify that the API is being built and used in a stable and successful way, consistent with the expected use of the Margin Service API.

Once a client demonstrates the successful use of the Margin Service API, the client will be provisioned access to the Production environment. 

Contact Support for API setup assistance.

For more details about the onboarding process, see the Developer Guide.

This page describes the following:

API Endpoints and Data Structure

For detailed information about the available Margin Service endpoints and the data structure used for each, please consult this Margin Service API, which includes a summary of features and schema content.

Testing Endpoints

This table includes the endpoints to use for testing. Please note the CORE API URLs are changing for all users in both the Test and Production environments to align to CME’s broader set of API endpoints. Users will have until February 28, 2025 to comply with these changes in the Test environment and until March 28, 2025 to comply with these changes in the Production environment. Users can cut over to the new URLs in Production any time between February 24 and March 28. Users who do not comply with these changes will experience a disruption in service following March 28. The old and new URLs are listed below.

For details on accessing the Production service endpoints following certification, please reach out to posttradeservice@cmegroup.com.

API Testing & Certification

Please reach out to posttradeservices@cmegroup.com to discuss licensing and testing the API.

Once entitled, to initiate a session with the API, make an initial request, passing in the username and password parameters within the HTTP request headers. These credentials must be those of a valid CME CORE UI user ID/CME Group Login ID, please contact support to be permissioned for the API. See Authentication and Entitlement for full details.

CME Group strongly recommends that clients utilize the CME Group API testing environment for the development and stabilization of their API calling mechanism(s).  Use the test API in as similar of a fashion as possible to mirror the API usage expected in Production. 

Hours

Perform testing on normal business days between Sunday 5 p.m. CT until Friday 10 p.m. CT. 

The production API and GUI is periodically down for deployments from Friday 4:30 p.m. CT - Sunday 5 p.m. CT

The API test environment is periodically down for maintenance from 5 a.m. CT - 12:00 p.m. CT on Wednesdays.

CME Group recommends testing the following metrics in the Test environment before becoming certified and accessing production:

Load Limits

The Margin Service API test infrastructure does not have the available bandwidth that the Production environment has. Throughout the onboarding process, any API calls into the test infrastructure must be limited. CME supports load testing and requests that any users work directly with CME Group to set up a load testing session.    

The limits are set specific to each of these areas and only apply in the New Release environment:

Authentication calls should be no more frequent than 1 call / second to establish a session.

Margin Service API supports multiple concurrent schemas that are backwards compatible. It is best practice to specify the version in the URL to get the response in that schema. If the version is not specified, the latest version is used. The Margin Service API supports multiple formats for transaction payloads. The API utilizes a custom XML language for requests and responses, which can contain contents in various formats, including industry standard XML formats such as FIXML (following FIXML 5.0 SP2), FpML (based on FpML 5.4 specifications), and .CSV as transaction formats.  

It is best practice to leverage the .CSV format as the message payload, which offers a performance boost in loading and deserialization times compared to FPML format. See sample .CSV requests.