Diffs & Version History

Nebula Writer is designed for reviewable AI work. When the assistant edits files, the goal is not blind automation. The goal is a clear before/after that you can accept, reject, or recover from.

When to Use This Page

  • You want to review AI edits before keeping them
  • You work with spreadsheets, DOCX, PPTX, Markdown, or LaTeX
  • You need to compare versions or recover an earlier state
  • You want a safer process for multi-step AI changes

Diff Review

Nebula Writer surfaces pending AI changes in the editor for supported formats.

Spreadsheet review banner showing AI changes and affected cells
Spreadsheet review banner showing AI changes and affected cells

Diffs can appear as:

  • Text additions and deletions
  • Inline change markers
  • Spreadsheet cell changes
  • DOCX model changes
  • PPTX slide or object changes
  • Review banners that summarize affected areas

The exact UI depends on the file type, but the workflow is the same: inspect the change, then accept or reject it.

Review Workflow

  1. Ask the assistant for a scoped edit.
  2. Wait for the change summary or diff surface.
  3. Inspect the affected file.
  4. Accept the change if it is correct.
  5. Reject the change if it is wrong or too broad.
  6. Save the file after review.

For important documents, ask for a plan first:

Read the current draft and propose the changes you would make. Do not edit yet.

Then approve the exact scope:

Apply the section-level structure changes only. Do not rewrite citations or equations.

Markdown and LaTeX Diffs

For text-first formats, review usually focuses on additions, deletions, and replacements in source text.

Use this workflow for:

  • Rewriting a paragraph
  • Reordering sections
  • Fixing a LaTeX compile error
  • Updating headings
  • Adding citation placeholders

Prompt example:

Edit the Method section for clarity. Preserve every equation and citation key.

DOCX Diffs

DOCX changes can involve document structure as well as text. Nebula Writer uses format-aware operations so AI edits can preserve the shape of the document.

Good DOCX review targets:

  • Heading structure
  • Paragraph text
  • Lists and formatting
  • Tables
  • Comments and revisions where supported
  • PDF export checks after editing

Prompt example:

Find inconsistent headings in this DOCX report and propose a reviewable fix.

Spreadsheet Diffs

Spreadsheet edits are reviewed by cell, range, sheet, or structural summary where available.

Review spreadsheet changes carefully when they affect:

  • Formulas
  • Named ranges
  • Merged cells
  • Hidden rows or columns
  • Workbook sheets
  • Data used by a report or presentation

Prompt example:

Update the summary sheet using the Data sheet, but show me the affected cells before I accept.

Presentation Diffs

PPTX changes can include slide additions, text edits, shape movement, table updates, or image changes.

Review deck changes for:

  • Slide order
  • Speaker notes
  • Object placement
  • Brand colors
  • Alt text and accessibility
  • Exported PDF appearance

Prompt example:

Create a new executive summary slide after slide 1. Keep the deck style consistent.

Version History

The saved version menu helps you inspect and recover important document states.

Use version history when:

  • You accepted an edit and later changed your mind
  • You need to compare a draft before and after a larger rewrite
  • You want a checkpoint before a multi-step assistant task
  • You are preparing a final deliverable

Save before major changes. That gives you an easier recovery point.

Action History

AI action history helps you understand what the assistant did during a session. Use it when an edit touched more files than expected, when you need to audit a generated artifact, or when you want to repeat part of a workflow.

Safer Prompt Patterns

Ask Before Editing

Review this document and list the changes you recommend. Do not edit yet.

Limit the Scope

Only edit the introduction. Do not change section headings, citations, tables, or equations.

Require a Summary

After editing, summarize every file and section you changed.

Protect Data

Analyze the workbook, but do not overwrite formulas or hidden sheets.

Best Practices

  • Keep edits small enough to review
  • Ask for plans before large rewrites
  • Save before major AI work
  • Check generated citations and calculations manually
  • Review Office-format changes in the visual editor
  • Export final DOCX or PPTX deliverables to PDF for a last layout check