CodeCommit - notifications for author of PR's

I had the same exact use case that I wanted to see in CodeCommit, because I've been very used to that in GitHub and GitLab. The only thing I've been able to find so far has been setting up a Lambda function, triggered via EventBridge when PR comments are added, which extracts the commit comment, and then sends that to an SNS topic, to which folks are subscribed. I haven't seen anything out of the box in CodeCommit.