---
title: Review changes
description: Read the diff an agent produced, file by file.
section: Guides
order: 3
---

# Review changes

Every agent works on a branch or in a worktree. The changes pane shows what the agent changed there, as a diff against the base.

## Open the changes pane

The changes pane sits on the right side of the window. Select the changes control at the top of the window if it is collapsed. Drag its edge to resize it.

## Read the diff

The pane lists changed files. Expand a file to read it line by line:

- Added lines and removed lines are marked with gutter indicators.
- Collapse a file when you finish with it.
- The pane shows a status while it prepares the diff, and a clear error if the diff cannot be read.

The diff stays live while the agent works. Check it mid-run, not only at the end.

## Open a changed file

Files the agent produced or touched open from the transcript and the file tree:

- **Open in default app.** Opens the file with your system's app for that type.
- **Show in folder.** Reveals the file in Finder or Explorer.
- **Open in browser.** Opens HTML and PDF files in a browser tab, sandboxed. Available on macOS.
- **Copy path.**

Spreadsheets and CSV files open as a read-only table with sheet tabs, so you can check an agent's data work without Excel. Very large tables are truncated with a banner that says so.

Files that live on another device are copied to a local cache when you open them. Large files above the cache limit do not open remotely; open them on the host device.

## Act on the review

The changes pane is for reading. To accept, reject, or continue the work, go back to the composer and tell the agent. It holds the branch, so it can revise, revert, or extend anything you saw.

## Next steps

- [Steer and queue](steer-and-queue.md): send revision notes.
- [Attachments and output files](attachments-and-output-files.md): more ways to open agent output.