Authentication on the content rest api

Before I get started, I’d appreciate a confirmation on protecting the content rest api with authentication. I’m interested in serving a single-page application to be hosted on a server that gets the content (it serves) from the content rest api, but the content rest api will live in one network while the single-page-application will be hosted in another — so this traffic has to be private. The example seems to assume the api and the single-page-application will live on the same system, so no authentication is mentioned.

I’m aware the web server to host the single-page-application will have to download the content from the content-rest-api using non-browser technology — otherwise there’d be security.

Thank you.