rexmod turns Superlogical's Rex into a review harness for coding agents

Rex already runs coding agents, but its own surface does not record what an agent changed between turns or give a place to review that code. rexmod fills that gap by snapshotting the working tree when a message is sent and again when the agent finishes, so the panel can show Last Turn next to Uncommitted, Branch and a Files tree. Clicking a file opens it in Neovim at the changed line with LSP, completion and live diagnostics, and a Space r on a line or selection leaves a review comment.

The comments are the second half of the loop. They ride along with the user's next message to the agent as a short list of file:line, the code and the note, or go right away from the panel's comment badge. Because each note is tied to the agent pane it was written for, a multi-agent tab keeps notes with the right agent, and the agent name at the bottom of the panel doubles as a switch. The architecture is a Swift dylib for the panel plus a Go CLI that talks to Rex's API and keeps state under .git/rexmod, with the installer adding a weak load command and re-signing Rex ad hoc.

The trade-off is maintenance. Every Rex update needs a re-patch, and Codex users must trust hooks once with /hooks, while OpenCode needs a quit after installing so plugins load. A known limit appears with two Codex panes in the same repository: the notes stay pending rather than being sent to the wrong pane.