Here are some available options:
- deploy mserv on your on-premises, configuring it to use your S3 bucket with AWS IAM auth, then configure the gateway to use your mserv deployment’s endpoint. It doesn’t explicitly state it but you do need MongoDB. There is a sample config you could use
- use pre-signed S3 object endpoints, but they’re only available for up to 7 days
- use some other S3-to-HTTP proxy
Hope this helps