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DOCX

AnthropicOfficialPublished by Anthropic

  • Skill
  • Tool integration
  • Documents and content
  • Apache-2.0
  • Low risk
  • Has scripts

From the author

Use this skill whenever the user wants to create, read, edit, or manipulate Word documents (.docx files) or Word templates (.dotx files). Triggers include: any mention of 'Word doc', 'word document', '.docx', '.dotx', or requests to produce professional documents with formatting like tables of contents, headings, page numbers, or letterheads. Also use when extracting or reorganizing content from .docx or .dotx files, inserting or replacing images in documents, performing find-and-replace in Word files, working with tracked changes or comments, or converting content into a polished Word document. If the user asks for a 'report', 'memo', 'letter', 'template', or similar deliverable as a Word or .docx file, use this skill. Do NOT use for PDFs, spreadsheets, Google Docs, or general coding tasks unrelated to document generation.
— the description by Anthropic

AutoGineer summary

Written by AutoGineer from the skill’s own files, not by the author

This skill provides a structured approach to working with Word documents by leveraging the docx-js library for creation and XML manipulation for editing. It includes specialized scripts for merging fragmented text runs, managing tracked changes, inserting comments, and validating document structure against XSD schemas. The skill also supports document conversion and visual verification using external tools like LibreOffice and Poppler.

What it does

  • Generates new .docx and .dotx files using the docx-js library.
  • Edits existing documents by manipulating underlying XML structures.
  • Merges fragmented text runs to facilitate accurate find-and-replace operations.
  • Manages tracked changes and redlining with validation support.
  • Inserts and anchors comments into document content.
  • Converts legacy .doc files and validates document integrity.

When to use it

  • When you need to generate professional documents like reports or letters programmatically.
  • When you must perform precise edits on existing Word files that require XML-level access.
  • When you need to automate the insertion of comments or track changes in a document.
  • When you need to convert or validate Word documents for specific formatting requirements.

Advantages

  • Provides programmatic control over complex Word document structures.
  • Includes helper scripts to handle common XML-related issues like fragmented text runs.
  • Supports automated validation of document structure and tracked changes.
  • Enables headless conversion and visual verification of document output.

Usage examples

“Create a new Word document with a table of contents and a custom letterhead.”
The agent uses the docx-js library to construct a document with defined headings and layout elements.
“Edit this contract.docx to add a comment on the payment clause.”
The agent uses the comment.py script to inject the comment and anchor it to the specified text.
“Merge the text runs in this document so I can perform a find-and-replace.”
The agent runs the merge_runs.py script to coalesce fragmented XML runs into contiguous strings.
“Convert this legacy .doc file to .docx and validate it.”
The agent uses soffice to convert the file and then runs the validation script to check for errors.

Install

  1. Download the skill as a ZIP:

    https://autogineer.com/agent-skills/anthropics/docx/download
  2. Unzip it into the cross-client skills folder of your project:

    mkdir -p .agents/skills && unzip docx.zip -d .agents/skills

Documentation by Anthropic

DOCX creation, editing, and analysis

A .docx is a ZIP archive of XML files. Choose your approach by task:

TaskApproach
Create a new documentWrite a docx (npm) script — see gotchas below
Edit an existing documentunzip → edit word/document.xml → zip (docx-js cannot open existing files)
Read contentpandoc -t markdown file.docx

Script paths below are relative to this skill's directory.

Creating with docx-js — gotchas

docx is preinstalled — do not run npm install first; write the script and require('docx') directly. Only if that require fails: npm install docx. The model knows the API; these are the footguns:

  • Page size defaults to A4. For US Letter set page: { size: { width: 12240, height: 15840 } } (DXA; 1440 = 1″).

  • Landscape: pass portrait dimensions and orientation: PageOrientation.LANDSCAPE — docx-js swaps width/height internally.

  • Tables need dual widths: set columnWidths on the table AND width on every cell, both in WidthType.DXA (PERCENTAGE breaks in Google Docs). Column widths must sum to the table width.

  • Table shading: use ShadingType.CLEAR, never SOLID (renders black).

  • Lists: never insert • literally; use a numbering config with LevelFormat.BULLET.

  • ImageRun requires type: ("png", "jpg", …).

  • PageBreak must be inside a Paragraph.

  • Never use \n — use separate Paragraph elements.

  • TOC: headings must use built-in HeadingLevel.*; custom heading styles need outlineLevel set or they won't appear.

  • Don't use a table as a horizontal rule — use a paragraph bottom border instead.

  • Dot-leader / right-aligned-on-same-line: use PositionalTab (alignment: PositionalTabAlignment.RIGHT, leader: PositionalTabLeader.DOT) inside a TextRun, not literal . or space padding.

Verify the output

After writing a .docx, render it and look at it:

python scripts/office/soffice.py --headless --convert-to pdf output.docx
pdftoppm -jpeg -r 100 output.pdf page
ls page-*.jpg   # then Read the images

pdftoppm zero-pads page numbers to the width of the page count (page-01.jpg…page-12.jpg).

Editing existing documents

Legacy .doc files must be converted first: python scripts/office/soffice.py --headless --convert-to docx file.doc.

unzip -q doc.docx -d unpacked/
find unpacked -type l -delete   # strip symlink entries — docx from external parties is untrusted
python scripts/merge_runs.py unpacked/   # coalesce fragmented runs so text is findable
# edit unpacked/word/document.xml in place — do NOT reformat or pretty-print
(cd unpacked && rm -f ../out.docx && zip -Xr ../out.docx .)
python scripts/office/validate.py out.docx --original doc.docx   # XSD checks; --auto-repair fixes common issues
# redlining? add --author "<the name you redlined under>" to check every edit is tracked

Word splits text across many <w:r> runs (revision ids, spell-check markers), so a phrase you can see in the document often doesn't exist as a contiguous string in the XML. merge_runs.py merges adjacent identically-formatted runs in word/document.xml without changing content or rendering; it also accepts a .docx directly (python scripts/merge_runs.py doc.docx -o merged.docx).

Tracked changes: when redlining, validate with --author "<the name you redlined under>" (needs --original) — it reports any text you changed without a <w:ins>/<w:del> around it, which is easy to do by accident and invisible in the accepted view. Wrap runs in <w:ins>/<w:del> with w:id, w:author, w:date attributes. Inside <w:del>, the text element is <w:delText>, not <w:t>. A deleted paragraph mark (<w:pPr><w:rPr><w:del w:id=".." w:author=".." w:date=".."/></w:rPr></w:pPr>) means "merge this paragraph into the next" — so deleting a paragraph outright is that plus a <w:del> around every run. The <w:del/> must come before the rPr's other children; their order is schema-enforced.

To produce a clean copy with all tracked changes accepted: python scripts/accept_changes.py in.docx out.docx.

Accepting a deleted paragraph mark should join that paragraph to the one below it, so a paragraph whose runs are all deleted vanishes. Word does this; accept_changes.py and pandoc --track-changes=accept don't always. Both fail the same way — they strip the deleted text but leave the emptied paragraph behind, which reads as a stray empty bullet when it was auto-numbered:

  • pandoc --track-changes=accept never joins the paragraphs.

  • accept_changes.py (LibreOffice) joins them correctly, except when the deleted paragraph is followed by an empty spacer paragraph.

An empty bullet in either view is an artifact of that view, not a defect in the document. Check paragraph deletions in the XML.

Comments

Comments require six cross-linked files. Use the helper — directory mode when you'll also be editing document.xml (saves an unzip/rezip cycle), .docx-direct mode otherwise:

# Against an already-unpacked directory (preferred when also placing markers)
python scripts/comment.py unpacked/ "Fees & expenses cap is too low"
python scripts/comment.py unpacked/ "Agreed" --parent 0

# Against a .docx directly
python scripts/comment.py contract.docx "This cap is too low" -o annotated.docx

The script writes comments.xml, commentsExtended.xml, commentsIds.xml, commentsExtensible.xml, the relationships, and the content-type overrides. Comment IDs are auto-assigned. It then prints the <w:commentRangeStart>/<w:commentRangeEnd>/<w:commentReference> snippet to add to word/document.xml so the comment anchors to specific text — until you place those markers, the comment exists but is not visible.

Dependencies

docx (npm, preinstalled — install only if require('docx') fails) · pandoc · LibreOffice (soffice) · pdftoppm (Poppler)

Files

scripts/office/validators/docx.py

"""
Validator for Word document XML files against XSD schemas.
"""

import random
import re
import tempfile
import zipfile
from pathlib import Path

import defusedxml.minidom
import lxml.etree

from helpers import safe_extract

from .base import BaseSchemaValidator


class DOCXSchemaValidator(BaseSchemaValidator):

    WORD_2006_NAMESPACE = "http://schemas.openxmlformats.org/wordprocessingml/2006/main"
    W14_NAMESPACE = "http://schemas.microsoft.com/office/word/2010/wordml"
    W16CID_NAMESPACE = "http://schemas.microsoft.com/office/word/2016/wordml/cid"

    ELEMENT_RELATIONSHIP_TYPES = {}

    def validate(self):
        if not self.validate_xml():
            return False

        all_valid = True
        if not self.validate_namespaces():
            all_valid = False

        if not self.validate_unique_ids():
            all_valid = False

        if not self.validate_file_references():
            all_valid = False

        if not self.validate_content_types():
            all_valid = False

        if not self.validate_against_xsd():
            all_valid = False

        if not self.validate_whitespace_preservation():
            all_valid = False

        if not self.validate_deletions():
            all_valid = False

        if not self.validate_insertions():
            all_valid = False

        if not self.validate_all_relationship_ids():
            all_valid = False

        if not self.validate_id_constraints():
            all_valid = False

        if not self.validate_comment_markers():
            all_valid = False

        self.compare_paragraph_counts()

        return all_valid

    def validate_whitespace_preservation(self):
        errors = []

        for xml_file in self.xml_files:
            if xml_file.name != "document.xml":
                continue

            try:
                root = lxml.etree.parse(str(xml_file)).getroot()

                for elem in root.iter(f"{{{self.WORD_2006_NAMESPACE}}}t"):
                    if elem.text:
                        text = elem.text
                        if re.search(r"^[ \t\n\r]", text) or re.search(
                            r"[ \t\n\r]$", text
                        ):
                            xml_space_attr = f"{{{self.XML_NAMESPACE}}}space"
                            if (
                                xml_space_attr not in elem.attrib
                                or elem.attrib[xml_space_attr] != "preserve"
                            ):
                                text_preview = (
                                    repr(text)[:50] + "..."
                                    if len(repr(text)) > 50
                                    else repr(text)
                                )
                                errors.append(
                                    f"  {xml_file.relative_to(self.unpacked_dir)}: "
                                    f"Line {elem.sourceline}: w:t element with whitespace missing xml:space='preserve': {text_preview}"
                                )

            except (lxml.etree.XMLSyntaxError, Exception) as e:
                errors.append(
                    f"  {xml_file.relative_to(self.unpacked_dir)}: Error: {e}"
                )

        if errors:
            print(f"FAILED - Found {len(errors)} whitespace preservation violations:")
            for error in errors:
                print(error)
            return False
        else:
            if self.verbose:
                print("PASSED - All whitespace is properly preserved")
            return True

    def validate_deletions(self):
        errors = []

        for xml_file in self.xml_files:
            if xml_file.name != "document.xml":
                continue

            try:
                root = lxml.etree.parse(str(xml_file)).getroot()
                namespaces = {"w": self.WORD_2006_NAMESPACE}

                for t_elem in root.xpath(".//w:del//w:t", namespaces=namespaces):
                    if t_elem.text:
                        text_preview = (
                            repr(t_elem.text)[:50] + "..."
                            if len(repr(t_elem.text)) > 50
                            else repr(t_elem.text)
                        )
                        errors.append(
                            f"  {xml_file.relative_to(self.unpacked_dir)}: "
                            f"Line {t_elem.sourceline}: <w:t> found within <w:del>: {text_preview}"
                        )

                for instr_elem in root.xpath(
                    ".//w:del//w:instrText", namespaces=namespaces
                ):
                    text_preview = (
                        repr(instr_elem.text or "")[:50] + "..."
                        if len(repr(instr_elem.text or "")) > 50
                        else repr(instr_elem.text or "")
                    )
                    errors.append(
                        f"  {xml_file.relative_to(self.unpacked_dir)}: "
                        f"Line {instr_elem.sourceline}: <w:instrText> found within <w:del> (use <w:delInstrText>): {text_preview}"
                    )

            except (lxml.etree.XMLSyntaxError, Exception) as e:
                errors.append(
                    f"  {xml_file.relative_to(self.unpacked_dir)}: Error: {e}"
                )

        if errors:
            print(f"FAILED - Found {len(errors)} deletion validation violations:")
            for error in errors:
                print(error)
            return False
        else:
            if self.verbose:
                print("PASSED - No w:t elements found within w:del elements")
            return True

    def count_paragraphs_in_unpacked(self):
        count = 0

        for xml_file in self.xml_files:
            if xml_file.name != "document.xml":
                continue

            try:
                root = lxml.etree.parse(str(xml_file)).getroot()
                paragraphs = root.findall(f".//{{{self.WORD_2006_NAMESPACE}}}p")
                count = len(paragraphs)
            except Exception as e:
                print(f"Error counting paragraphs in unpacked document: {e}")

        return count

    def count_paragraphs_in_original(self):
        original = self.original_file
        if original is None:
            return 0

        count = 0

        try:
            with tempfile.TemporaryDirectory() as temp_dir:
                with zipfile.ZipFile(original, "r") as zip_ref:
                    safe_extract(zip_ref, Path(temp_dir))

                doc_xml_path = temp_dir + "/word/document.xml"
                root = lxml.etree.parse(doc_xml_path).getroot()

                paragraphs = root.findall(f".//{{{self.WORD_2006_NAMESPACE}}}p")
                count = len(paragraphs)

        except Exception as e:
            print(f"Error counting paragraphs in original document: {e}")

        return count

    def validate_insertions(self):
        errors = []

        for xml_file in self.xml_files:
            if xml_file.name != "document.xml":
                continue

            try:
                root = lxml.etree.parse(str(xml_file)).getroot()
                namespaces = {"w": self.WORD_2006_NAMESPACE}

                invalid_elements = root.xpath(
                    ".//w:ins//w:delText[not(ancestor::w:del)]", namespaces=namespaces
                )

                for elem in invalid_elements:
                    text_preview = (
                        repr(elem.text or "")[:50] + "..."
                        if len(repr(elem.text or "")) > 50
                        else repr(elem.text or "")
                    )
                    errors.append(
                        f"  {xml_file.relative_to(self.unpacked_dir)}: "
                        f"Line {elem.sourceline}: <w:delText> within <w:ins>: {text_preview}"
                    )

            except (lxml.etree.XMLSyntaxError, Exception) as e:
                errors.append(
                    f"  {xml_file.relative_to(self.unpacked_dir)}: Error: {e}"
                )

        if errors:
            print(f"FAILED - Found {len(errors)} insertion validation violations:")
            for error in errors:
                print(error)
            return False
        else:
            if self.verbose:
                print("PASSED - No w:delText elements within w:ins elements")
            return True

    def compare_paragraph_counts(self):
        new_count = self.count_paragraphs_in_unpacked()
        if self.original_file is None:
            print(f"\nParagraphs: {new_count}")
            return

        original_count = self.count_paragraphs_in_original()
        diff = new_count - original_count
        diff_str = f"+{diff}" if diff > 0 else str(diff)
        print(f"\nParagraphs: {original_count} → {new_count} ({diff_str})")

    def _parse_id_value(self, val: str, base: int = 16) -> int:
        return int(val, base)

    def validate_id_constraints(self):
        errors = []
        para_id_attr = f"{{{self.W14_NAMESPACE}}}paraId"
        durable_id_attr = f"{{{self.W16CID_NAMESPACE}}}durableId"

        for xml_file in self.xml_files:
            try:
                for elem in lxml.etree.parse(str(xml_file)).iter():
                    if val := elem.get(para_id_attr):
                        try:
                            if self._parse_id_value(val, base=16) >= 0x80000000:
                                errors.append(
                                    f"  {xml_file.name}:{elem.sourceline}: paraId={val} >= 0x80000000"
                                )
                        except ValueError:
                            errors.append(
                                f"  {xml_file.name}:{elem.sourceline}: "
                                f"paraId={val} is not valid hex"
                            )

                    if val := elem.get(durable_id_attr):
                        if xml_file.name == "numbering.xml":
                            try:
                                if self._parse_id_value(val, base=10) >= 0x7FFFFFFF:
                                    errors.append(
                                        f"  {xml_file.name}:{elem.sourceline}: "
                                        f"durableId={val} >= 0x7FFFFFFF"
                                    )
                            except ValueError:
                                errors.append(
                                    f"  {xml_file.name}:{elem.sourceline}: "
                                    f"durableId={val} must be decimal in numbering.xml"
                                )
                        else:
                            try:
                                if self._parse_id_value(val, base=16) >= 0x7FFFFFFF:
                                    errors.append(
                                        f"  {xml_file.name}:{elem.sourceline}: "
                                        f"durableId={val} >= 0x7FFFFFFF"
                                    )
                            except ValueError:
                                errors.append(
                                    f"  {xml_file.name}:{elem.sourceline}: "
                                    f"durableId={val} is not valid hex"
                                )
            except lxml.etree.XMLSyntaxError:
                continue  

        if errors:
            print(f"FAILED - {len(errors)} ID constraint violations:")
            for e in errors:
                print(e)
        elif self.verbose:
            print("PASSED - All paraId/durableId values within constraints")
        return not errors

    def validate_comment_markers(self):
        errors = []

        document_xml = None
        comments_xml = None
        for xml_file in self.xml_files:
            if xml_file.name == "document.xml" and "word" in str(xml_file):
                document_xml = xml_file
            elif xml_file.name == "comments.xml":
                comments_xml = xml_file

        if not document_xml:
            if self.verbose:
                print("PASSED - No document.xml found (skipping comment validation)")
            return True

        try:
            doc_root = lxml.etree.parse(str(document_xml)).getroot()
            namespaces = {"w": self.WORD_2006_NAMESPACE}

            range_starts = {
                elem.get(f"{{{self.WORD_2006_NAMESPACE}}}id")
                for elem in doc_root.xpath(
                    ".//w:commentRangeStart", namespaces=namespaces
                )
            }
            range_ends = {
                elem.get(f"{{{self.WORD_2006_NAMESPACE}}}id")
                for elem in doc_root.xpath(
                    ".//w:commentRangeEnd", namespaces=namespaces
                )
            }
            references = {
                elem.get(f"{{{self.WORD_2006_NAMESPACE}}}id")
                for elem in doc_root.xpath(
                    ".//w:commentReference", namespaces=namespaces
                )
            }

            orphaned_ends = range_ends - range_starts
            for comment_id in sorted(
                orphaned_ends, key=lambda x: int(x) if x and x.isdigit() else 0
            ):
                errors.append(
                    f'  document.xml: commentRangeEnd id="{comment_id}" has no matching commentRangeStart'
                )

            orphaned_starts = range_starts - range_ends
            for comment_id in sorted(
                orphaned_starts, key=lambda x: int(x) if x and x.isdigit() else 0
            ):
                errors.append(
                    f'  document.xml: commentRangeStart id="{comment_id}" has no matching commentRangeEnd'
                )

            comment_ids = set()
            if comments_xml and comments_xml.exists():
                comments_root = lxml.etree.parse(str(comments_xml)).getroot()
                comment_ids = {
                    elem.get(f"{{{self.WORD_2006_NAMESPACE}}}id")
                    for elem in comments_root.xpath(
                        ".//w:comment", namespaces=namespaces
                    )
                }

                marker_ids = range_starts | range_ends | references
                invalid_refs = marker_ids - comment_ids
                for comment_id in sorted(
                    invalid_refs, key=lambda x: int(x) if x and x.isdigit() else 0
                ):
                    if comment_id:  
                        errors.append(
                            f'  document.xml: marker id="{comment_id}" references non-existent comment'
                        )

        except (lxml.etree.XMLSyntaxError, Exception) as e:
            errors.append(f"  Error parsing XML: {e}")

        if errors:
            print(f"FAILED - {len(errors)} comment marker violations:")
            for error in errors:
                print(error)
            return False
        else:
            if self.verbose:
                print("PASSED - All comment markers properly paired")
            return True

    def repair(self) -> int:
        repairs = super().repair()
        repairs += self.repair_durableId()
        return repairs

    def repair_durableId(self) -> int:
        DURABLE_ID_ATTRS = ("w16cid:durableId", "w16cex:durableId")
        repairs = 0
        renames: dict = {}  

        for xml_file in self.xml_files:
            try:
                content = xml_file.read_text(encoding="utf-8")
                dom = defusedxml.minidom.parseString(content)
                is_numbering = xml_file.name == "numbering.xml"
                base = 10 if is_numbering else 16
                pending = []  
                seen_in_file = set()
                modified = False

                for elem in dom.getElementsByTagName("*"):
                    for attr_name in DURABLE_ID_ATTRS:
                        if not elem.hasAttribute(attr_name):
                            continue

                        durable_id = elem.getAttribute(attr_name)
                        try:
                            key = self._parse_id_value(durable_id, base=base)
                            needs_repair = key >= 0x7FFFFFFF
                        except ValueError:
                            key = durable_id
                            needs_repair = True

                        if needs_repair:
                            if key in seen_in_file:
                                value = random.randint(1, 0x7FFFFFFE)
                            else:
                                seen_in_file.add(key)
                                if key not in renames:
                                    renames[key] = random.randint(1, 0x7FFFFFFE)
                                value = renames[key]
                            new_id = str(value) if is_numbering else f"{value:08X}"

                            elem.setAttribute(attr_name, new_id)
                            pending.append(
                                f"  Repaired: {xml_file.name}: durableId {durable_id} → {new_id}"
                            )
                            modified = True

                if modified:
                    xml_file.write_bytes(dom.toxml(encoding="UTF-8"))
                    for message in pending:
                        print(message)
                    repairs += len(pending)

            except Exception:
                pass

        return repairs


if __name__ == "__main__":
    raise RuntimeError("This module should not be run directly.")

Requirements and compatibility

Written for: Claude Code, Claude apps

Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta

“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.

Needs: Needs Python, Needs Node.js

Security

What our scanner noticed· Low risk

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Attribution and licence

Published by
Anthropic
Publisher
Anthropic (Official)
Source
anthropics/skills · skills/docx · commit 2c5958e
Licence
Apache License 2.0 (redistribution allowed)
  • ATTRIBUTION.md (written by AutoGineer)
Synced

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Download ZIP

The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download docx.zip