I was looking at CLI-only solutions a while ago and the best thing I found was to use something like revdiff: https://github.com/umputun/revdiff
For instance, in Claude Code you can have it bring up this TUI overlay after every edit it makes (it literally is an overlay, rather than a separate tab in your terminal) and you can annotate line-by-line anything you want changed or rejected. Then once you exit the overlay those suggestions are automatically piped back into the agent.
I tried a few of these TUI-based code annotators, and this one is by far the best. It also works for files not under version control.
I'm currently not using it as I also prefer something more akin to "text editor with agent built in", but I wanted to mention here in case you were curious.
For instance, in Claude Code you can have it bring up this TUI overlay after every edit it makes (it literally is an overlay, rather than a separate tab in your terminal) and you can annotate line-by-line anything you want changed or rejected. Then once you exit the overlay those suggestions are automatically piped back into the agent.
I tried a few of these TUI-based code annotators, and this one is by far the best. It also works for files not under version control.
I'm currently not using it as I also prefer something more akin to "text editor with agent built in", but I wanted to mention here in case you were curious.