DOCX creation, editing, and analysis
Overview
A .docx file is a ZIP archive containing XML files.
Quick Reference
| Task | Approach |
|---|---|
| Read/analyze content | pandoc or unpack for raw XML |
| Create new document | Use docx-js - see Creating New Documents below |
| Edit existing document | Unpack → edit XML → repack - see Editing Existing Documents below |
Converting .doc to .docx
Legacy .doc files must be converted before editing:
python scripts/office/soffice.py --headless --convert-to docx document.doc
Reading Content
# Text extraction with tracked changes
pandoc --track-changes=all document.docx -o output.md
# Raw XML access
python scripts/office/unpack.py document.docx unpacked/
Converting to Images
python scripts/office/soffice.py --headless --convert-to pdf document.docx
pdftoppm -jpeg -r 150 document.pdf page
For deterministic page-sized PNG output, use the bundled renderer. It checks for LibreOffice and Poppler, calculates a suitable DPI from the document page size, and writes one image per page:
python scripts/render_docx.py document.docx --output_dir /tmp/rendered-docx
Inspect every rendered page before delivery. Text extraction and OOXML validation cannot detect clipping, unexpected pagination, or visual overlap.
Accepting Tracked Changes
To produce a clean document with all tracked changes accepted (requires LibreOffice):
python scripts/accept_changes.py input.docx output.docx
Creating New Documents
Generate .docx files with JavaScript, then validate. Install: npm install -g docx
Setup
const { Document, Packer, Paragraph, TextRun, Table, TableRow, TableCell, ImageRun,
Header, Footer, AlignmentType, PageOrientation, LevelFormat, ExternalHyperlink,
InternalHyperlink, Bookmark, FootnoteReferenceRun, PositionalTab,
PositionalTabAlignment, PositionalTabRelativeTo, PositionalTabLeader,
TabStopType, TabStopPosition, Column, SectionType,
TableOfContents, HeadingLevel, BorderStyle, WidthType, ShadingType,
VerticalAlign, PageNumber, PageBreak } = require('docx');
const doc = new Document({ sections: [{ children: [/* content */] }] });
Packer.toBuffer(doc).then(buffer => fs.writeFileSync("doc.docx", buffer));
Validation
After creating the file, validate it. If validation fails, unpack, fix the XML, and repack.
python scripts/office/validate.py doc.docx
Page Size
Read the detailed procedure and examples when working on this part of the task.
Styles (Override Built-in Headings)
Use Arial as the default font (universally supported). Keep titles black for readability.
const doc = new Document({
styles: {
default: { document: { run: { font: "Arial", size: 24 } } }, // 12pt default
paragraphStyles: [
// IMPORTANT: Use exact IDs to override built-in styles
{ id: "Heading1", name: "Heading 1", basedOn: "Normal", next: "Normal", quickFormat: true,
run: { size: 32, bold: true, font: "Arial" },
paragraph: { spacing: { before: 240, after: 240 }, outlineLevel: 0 } }, // outlineLevel required for TOC
{ id: "Heading2", name: "Heading 2", basedOn: "Normal", next: "Normal", quickFormat: true,
run: { size: 28, bold: true, font: "Arial" },
paragraph: { spacing: { before: 180, after: 180 }, outlineLevel: 1 } },
]
},
sections: [{
children: [
new Paragraph({ heading: HeadingLevel.HEADING_1, children: [new TextRun("Title")] }),
]
}]
});
Lists (NEVER use unicode bullets)
// ❌ WRONG - never manually insert bullet characters
new Paragraph({ children: [new TextRun("• Item")] }) // BAD
new Paragraph({ children: [new TextRun("\u2022 Item")] }) // BAD
// ✅ CORRECT - use numbering config with LevelFormat.BULLET
const doc = new Document({
numbering: {
config: [
{ reference: "bullets",
levels: [{ level: 0, format: LevelFormat.BULLET, text: "•", alignment: AlignmentType.LEFT,
style: { paragraph: { indent: { left: 720, hanging: 360 } } } }] },
{ reference: "numbers",
levels: [{ level: 0, format: LevelFormat.DECIMAL, text: "%1.", alignment: AlignmentType.LEFT,
style: { paragraph: { indent: { left: 720, hanging: 360 } } } }] },
]
},
sections: [{
children: [
new Paragraph({ numbering: { reference: "bullets", level: 0 },
children: [new TextRun("Bullet item")] }),
new Paragraph({ numbering: { reference: "numbers", level: 0 },
children: [new TextRun("Numbered item")] }),
]
}]
});
// ⚠️ Each reference creates INDEPENDENT numbering
// Same reference = continues (1,2,3 then 4,5,6)
// Different reference = restarts (1,2,3 then 1,2,3)
Tables
Read the detailed procedure and examples when working on this part of the task.
Images
// CRITICAL: type parameter is REQUIRED
new Paragraph({
children: [new ImageRun({
type: "png", // Required: png, jpg, jpeg, gif, bmp, svg
data: fs.readFileSync("image.png"),
transformation: { width: 200, height: 150 },
altText: { title: "Title", description: "Desc", name: "Name" } // All three required
})]
})
Page Breaks
// CRITICAL: PageBreak must be inside a Paragraph
new Paragraph({ children: [new PageBreak()] })
// Or use pageBreakBefore
new Paragraph({ pageBreakBefore: true, children: [new TextRun("New page")] })
Hyperlinks
// External link
new Paragraph({
children: [new ExternalHyperlink({
children: [new TextRun({ text: "Click here", style: "Hyperlink" })],
link: "https://example.com",
})]
})
// Internal link (bookmark + reference)
// 1. Create bookmark at destination
new Paragraph({ heading: HeadingLevel.HEADING_1, children: [
new Bookmark({ id: "chapter1", children: [new TextRun("Chapter 1")] }),
]})
// 2. Link to it
new Paragraph({ children: [new InternalHyperlink({
children: [new TextRun({ text: "See Chapter 1", style: "Hyperlink" })],
anchor: "chapter1",
})]})
Footnotes
const doc = new Document({
footnotes: {
1: { children: [new Paragraph("Source: Annual Report 2024")] },
2: { children: [new Paragraph("See appendix for methodology")] },
},
sections: [{
children: [new Paragraph({
children: [
new TextRun("Revenue grew 15%"),
new FootnoteReferenceRun(1),
new TextRun(" using adjusted metrics"),
new FootnoteReferenceRun(2),
],
})]
}]
});
Tab Stops
// Right-align text on same line (e.g., date opposite a title)
new Paragraph({
children: [
new TextRun("Company Name"),
new TextRun("\tJanuary 2025"),
],
tabStops: [{ type: TabStopType.RIGHT, position: TabStopPosition.MAX }],
})
// Dot leader (e.g., TOC-style)
new Paragraph({
children: [
new TextRun("Introduction"),
new TextRun({ children: [
new PositionalTab({
alignment: PositionalTabAlignment.RIGHT,
relativeTo: PositionalTabRelativeTo.MARGIN,
leader: PositionalTabLeader.DOT,
}),
"3",
]}),
],
})
Multi-Column Layouts
// Equal-width columns
sections: [{
properties: {
column: {
count: 2, // number of columns
space: 720, // gap between columns in DXA (720 = 0.5 inch)
equalWidth: true,
separate: true, // vertical line between columns
},
},
children: [/* content flows naturally across columns */]
}]
// Custom-width columns (equalWidth must be false)
sections: [{
properties: {
column: {
equalWidth: false,
children: [
new Column({ width: 5400, space: 720 }),
new Column({ width: 3240 }),
],
},
},
children: [/* content */]
}]
Force a column break with a new section using type: SectionType.NEXT_COLUMN.
Table of Contents
// CRITICAL: Headings must use HeadingLevel ONLY - no custom styles
new TableOfContents("Table of Contents", { hyperlink: true, headingStyleRange: "1-3" })
Headers/Footers
sections: [{
properties: {
page: { margin: { top: 1440, right: 1440, bottom: 1440, left: 1440 } } // 1440 = 1 inch
},
headers: {
default: new Header({ children: [new Paragraph({ children: [new TextRun("Header")] })] })
},
footers: {
default: new Footer({ children: [new Paragraph({
children: [new TextRun("Page "), new TextRun({ children: [PageNumber.CURRENT] })]
})] })
},
children: [/* content */]
}]
Critical Rules for docx-js
- Set page size explicitly - docx-js defaults to A4; use US Letter (12240 x 15840 DXA) for US documents
- Landscape: pass portrait dimensions - docx-js swaps width/height internally; pass short edge as
width, long edge asheight, and setorientation: PageOrientation.LANDSCAPE - Never use
\n- use separate Paragraph elements - Never use unicode bullets - use
LevelFormat.BULLETwith numbering config - PageBreak must be in Paragraph - standalone creates invalid XML
- ImageRun requires
type- always specify png/jpg/etc - Always set table
widthwith DXA - never useWidthType.PERCENTAGE(breaks in Google Docs) - Tables need dual widths -
columnWidthsarray AND cellwidth, both must match - Table width = sum of columnWidths - for DXA, ensure they add up exactly
- Always add cell margins - use
margins: { top: 80, bottom: 80, left: 120, right: 120 }for readable padding - Use
ShadingType.CLEAR- never SOLID for table shading - Never use tables as dividers/rules - cells have minimum height and render as empty boxes (including in headers/footers); use
border: { bottom: { style: BorderStyle.SINGLE, size: 6, color: "2E75B6", space: 1 } }on a Paragraph instead. For two-column footers, use tab stops (see Tab Stops section), not tables - TOC requires HeadingLevel only - no custom styles on heading paragraphs
- Override built-in styles - use exact IDs: "Heading1", "Heading2", etc.
- Include
outlineLevel- required for TOC (0 for H1, 1 for H2, etc.)
Editing Existing Documents
Follow all 3 steps in order.
Step 1: Unpack
python scripts/office/unpack.py document.docx unpacked/
Extracts XML, pretty-prints, merges adjacent runs, and converts smart quotes to XML entities (“ etc.) so they survive editing. Use --merge-runs false to skip run merging.
Step 2: Edit XML
Edit files in unpacked/word/. See XML Reference below for patterns.
Use "Claude" as the author for tracked changes and comments, unless the user explicitly requests use of a different name.
Use the Edit tool directly for string replacement. Do not write Python scripts. Scripts introduce unnecessary complexity. The Edit tool shows exactly what is being replaced.
CRITICAL: Use smart quotes for new content. When adding text with apostrophes or quotes, use XML entities to produce smart quotes:
<!-- Use these entities for professional typography -->
<w:t>Here’s a quote: “Hello”</w:t>
| Entity | Character |
|---|---|
‘ |
‘ (left single) |
’ |
’ (right single / apostrophe) |
“ |
“ (left double) |
” |
” (right double) |
Adding comments: Use comment.py to handle boilerplate across multiple XML files (text must be pre-escaped XML):
python scripts/comment.py unpacked/ 0 "Comment text with & and ’"
python scripts/comment.py unpacked/ 1 "Reply text" --parent 0 # reply to comment 0
python scripts/comment.py unpacked/ 0 "Text" --author "Custom Author" # custom author name
Then add markers to document.xml (see Comments in XML Reference).
Step 3: Pack
python scripts/office/pack.py unpacked/ output.docx --original document.docx
Validates with auto-repair, condenses XML, and creates DOCX. Use --validate false to skip.
Auto-repair will fix:
durableId>= 0x7FFFFFFF (regenerates valid ID)- Missing
xml:space="preserve"on<w:t>with whitespace
Auto-repair won't fix:
- Malformed XML, invalid element nesting, missing relationships, schema violations
Common Pitfalls
- Replace entire
<w:r>elements: When adding tracked changes, replace the whole<w:r>...</w:r>block with<w:del>...<w:ins>...as siblings. Don't inject tracked change tags inside a run. - Preserve
<w:rPr>formatting: Copy the original run's<w:rPr>block into your tracked change runs to maintain bold, font size, etc.
XML Reference
Schema Compliance
- Element order in
<w:pPr>:<w:pStyle>,<w:numPr>,<w:spacing>,<w:ind>,<w:jc>,<w:rPr>last - Whitespace: Add
xml:space="preserve"to<w:t>with leading/trailing spaces - RSIDs: Must be 8-digit hex (e.g.,
00AB1234)
Tracked Changes
Read the detailed procedure and examples when working on this part of the task.
Comments
After running comment.py (see Step 2), add markers to document.xml. For replies, use --parent flag and nest markers inside the parent's.
CRITICAL: <w:commentRangeStart> and <w:commentRangeEnd> are siblings of <w:r>, never inside <w:r>.
<!-- Comment markers are direct children of w:p, never inside w:r -->
<w:commentRangeStart w:id="0"/>
<w:del w:id="1" w:author="Claude" w:date="2025-01-01T00:00:00Z">
<w:r><w:delText>deleted</w:delText></w:r>
</w:del>
<w:r><w:t> more text</w:t></w:r>
<w:commentRangeEnd w:id="0"/>
<w:r><w:rPr><w:rStyle w:val="CommentReference"/></w:rPr><w:commentReference w:id="0"/></w:r>
<!-- Comment 0 with reply 1 nested inside -->
<w:commentRangeStart w:id="0"/>
<w:commentRangeStart w:id="1"/>
<w:r><w:t>text</w:t></w:r>
<w:commentRangeEnd w:id="1"/>
<w:commentRangeEnd w:id="0"/>
<w:r><w:rPr><w:rStyle w:val="CommentReference"/></w:rPr><w:commentReference w:id="0"/></w:r>
<w:r><w:rPr><w:rStyle w:val="CommentReference"/></w:rPr><w:commentReference w:id="1"/></w:r>
Images
- Add image file to
word/media/ - Add relationship to
word/_rels/document.xml.rels:
<Relationship Id="rId5" Type=".../image" Target="media/image1.png"/>
- Add content type to
[Content_Types].xml:
<Default Extension="png" ContentType="image/png"/>
- Reference in document.xml:
<w:drawing>
<wp:inline>
<wp:extent cx="914400" cy="914400"/> <!-- EMUs: 914400 = 1 inch -->
<a:graphic>
<a:graphicData uri=".../picture">
<pic:pic>
<pic:blipFill><a:blip r:embed="rId5"/></pic:blipFill>
</pic:pic>
</a:graphicData>
</a:graphic>
</wp:inline>
</w:drawing>
Dependencies
- pandoc: Text extraction
- docx:
npm install -g docx(new documents) - LibreOffice: PDF conversion (auto-configured for sandboxed environments via
scripts/office/soffice.py) - Poppler:
pdftoppmfor images