The terms creative components and native components may be used interchangeably. The front part of the endpoint is:
QA API Base: https://t1qa1.mediamath.com/component_creatives/v1.0/ (or whichever QA server is being used)
Prod API Base: https://t1.mediamath.com/component_creatives/v1.0
Component Creatives are uploaded in the "Creatives Tab" within the Creatives Module, and is where creatives for native campaigns are uploaded.