We announced
Loading Credentials in Node.js using a Configured Credential Process
You can source credentials by using a method that isn't built into the SDK. To do this, specify a credential process in the shared AWS config file or the shared credentials file. If the AWS_SDK_LOAD_CONFIG
environment variable is set to any value, the SDK will prefer the process specified in the config file over the process specified in the credentials file (if any).
For details about specifying a credential process in the shared AWS config file or the shared credentials file, see the AWS CLI Command Reference, specifically the information about Sourcing Credentials From External Processes.
For information about using the AWS_SDK_LOAD_CONFIG
environment variable, see Using a Shared Config File in this document.