Review your code like a pull request. Let your agent fix what you find.

Drag across line numbers, or click the + next to a line, and write what you think. You can comment on one line, many lines, a file or the whole change.

Click Send. Claude Code or Codex goes through your comments one by one, changes the code and replies in each thread. Then you review its changes like any other diff.

Not sure about something? Mention an agent in any comment and it answers right there in the thread.

Ask for a review and, if you like, say what to look at. The agent reads the diff and leaves comments on the lines that matter, while you watch.

Use Claude Code, Codex or both. The model menu lists the models of every agent you have installed, grouped by agent, so picking a model also picks the agent. You can also pick how much effort it puts in.

Pick what you want to see from the menu next to the project name.

Pick a pull request from the branch menu. Diffity checks it out on your Mac, so you can read it, run it and comment as you go. Comments stay with each branch.

When you are done, click Submit review. Comments from GitHub show up in the diff too, so you can reply or resolve them from the app.

Open the Files tab, pick any file in the repo and comment on its lines. Even code the diff does not touch. Big files stay fast.

Keep your hands on the keyboard.

Open a repo once and it stays in the left rail.

Install the command once from the app menu: Diffity → Install ‘diffity’ Command. Then run it anywhere. Your agent can run it too, so you can ask Claude Code or Codex to open its changes in Diffity before it opens a PR.

Details that make long reviews easier.