The CA API Management OAuth Toolkit is a prerequisite for a on-premise integration in between CA API Management SaaS and the CA API Management Gateway.
What CA API Management OAuth Toolkit components are required for CA API Management SaaS Developer Portal?
If the requirement is only the on-premise integration and no other OAuth functionality, then these components are required:
The OAuth Database is also always required, please follow the OAuth documentation on this tasks.
The "Internal, Portal" component is only required if the environment is a two Gateway setup. Meaning one in the DMZ, one in the internal network where the internal one communicates with the OTK database.