Keep or discard: how to check every AI edit to a document

When the Nebula agent edits a file, the change waits for your decision. Keep edit keeps it. Discard edit puts the file back exactly as it was. This guide shows what the review bar tells you, how to check a change in each format, and how to undo a change later.

What happens to the file

The agent writes its changes into the file while it works, and Nebula Writer saves a restore point first. So if another app opens the file before you decide, it sees the agent's version.

When the agent finishes, a review bar appears above the document. If you discard, Nebula Writer restores the original from the restore point, byte for byte. If the file changed after the agent's edit, for example because you edited it in another app, Discard will not overwrite your newer version.

We test this. In one review-flow check, a Markdown file read "The result is preliminary." An edit changed that line to "The validated result is ready for review." After Discard, the file was identical to the original, byte for byte. The same check passes for LaTeX, Word, PowerPoint and Excel files.

Read the review bar

The bar's title says what kind of change is waiting. Under it you see the format and the number of changes, for example "PowerPoint · 3 changes".

Inspect changes opens a list of the individual changes, each with a Before and an After column. With the bar focused, press Y to keep and N to discard. Use J and K, or the arrow keys, to step through changes.

While a change is waiting, PDF export is paused. The app asks you to review the changes first.

Check a change in each format

Word, Excel and PowerPoint edits are kept or discarded as one decision. You can inspect each change, but you cannot keep some and drop others. Markdown, LaTeX and plain text are different: each change can be accepted or rejected on its own.

Word

Open Inspect changes and read the Before and After text. Then look at the page itself: spacing around the edit, page breaks, table widths, headers and footers. For contracts, or files with complex tracked changes, fields or macros, do a final check in Microsoft Word before you send them. See the Word editing guide.

Excel

The bar reads Review workbook edit. Click the changed cells and read the formula bar, not only the displayed value. Check the totals and charts that depend on those cells. The AI spreadsheet editor page shows the kinds of edits to expect.

PowerPoint

Look at the whole slide, not only the edited text box, and scan the thumbnails for slides that shifted. A moved shape can cover another one. The PowerPoint editing guide has a checklist.

LaTeX

Compile and look at the PDF as well as the changed lines. Accept the lines that are right and reject the rest, then compile again.

Markdown and text

Step through the changes and accept or reject each one.

Ask for changes that are easy to check

A small, clearly scoped edit is easier to verify than a broad one. Ask for findings first when the document is new to you:

Review the Executive Summary of @client-report.docx against
@sources/findings.xlsx. List every claim that the workbook does not support.
Do not edit the document.

You should see a list in the agent pane and no review bar, because nothing changed.

Then allow one bounded edit:

Revise only the second and third paragraphs of the Executive Summary using
the supported findings. Keep every number, table and heading style.

You should see one Review agent edit bar. Open Inspect changes, and if the agent touched anything outside those two paragraphs, discard and ask again with tighter limits.

Undo a change, now or later

Before a large edit, open History and choose Save a restore point. Restore points cover Markdown, text, LaTeX, Word, PowerPoint, Excel and CSV files. They are stored on your computer, and older automatic restore points may be removed over time. Restoring one file does not change the others in the project.

More detail is in the review and history guide. New to the app? Start with the quickstart, or see what the agent can do in each format.