pi-diff-cmux

GitHub-style diff review in cmux browser panes and surfaces for pi.

Commands

• /diff-cmux-pane [target] — opens the viewer in a new browser pane on the right, defaulting to unified mode.
• /diff-cmux-surface [target] — opens the viewer as a browser surface in the current pane, defaulting to split mode.

Supported targets

• uncommitted
• branch <name>
• commit <sha>

Examples:

• /diff-cmux-pane uncommitted
• /diff-cmux-pane branch main
• /diff-cmux-surface commit abc123

If you omit args, the extension offers an interactive target picker.

Viewer behavior

• Continuous changed-files stream, similar to GitHub's changed-files review view.
• Collapsible grouped-path sidebar with fuzzy search, status markers, comment badges, and reviewed indicators.
• Unified/split toggle and wrap toggle.
• Line, file, and overall comments.
• Manual reviewed/unreviewed tracking persisted in browser storage for that viewer token.
• Send individual comments from each draft textarea, use Cmd+Enter on macOS or Ctrl+Enter elsewhere, or send all unsent comments at once.
• Sent output is formatted as a compact “Please address the following feedback” prompt, and appends on a new line when the editor already has content.

cmux requirements

This extension expects:

• cmux to be installed
• a current cmux workspace
• /diff-cmux-surface to resolve the active pane via cmux identify

Local development

Install deps in diff-cmux/ if needed, then build the browser bundle:

cd diff-cmux
npm install
npm run build
bun test tests/*.test.ts

To load locally, symlink diff-cmux/ into ~/.pi/agent/extensions/diff-cmux and run /reload in pi.