office-word-diff

office-word-diff

When to Use

• You need to apply AI-generated edits as tracked changes in Word documents
• You're building a legal tool that produces DOCX output with redlines
• You need deterministic, word-level text comparison (not just line-level diff)
• You want to preserve formatting through document transformations
• You're integrating with Claude Code, Cursor, or other agents that produce document changes

How It Works

Core Problem

Most diff tools operate at the line or paragraph level. Word documents have structural complexity — nested lists, tables, headers, formatting runs — that line-based diffs destroy. office-word-diff solves the kernel-level problem: applying word-level tracked changes to DOCX while preserving formatting.

Architecture

1. Parse — Read DOCX via Office.js API, extract text runs with formatting metadata
2. Diff — Compute word-level differences between old and new text
3. Transform — Insert Word-compatible tracked changes (insertions/deletions) preserving formatting
4. Output — Return valid DOCX with native Word tracked changes

Usage

import { diffWords } from 'office-word-diff';

const result = await diffWords(oldDoc, newDoc, {
  trackChanges: true,
  author: 'LQClaw'
});

Key Features

• Granular tracked changes — Word-level, not paragraph-level
• Format preservation — Bold, italic, underlines survive transformation
• Nested structures — Handles tables, lists, headers correctly
• Agent-compatible — Works with Claude Code, Gemini CLI, Codex as backend
• Deterministic — Same input produces same output (unlike fragile text-matching approaches)

Audience and Work Shape

Audience: lawyers and developers building Word add-ins or document-transformation tools that emit native tracked changes. Output is consumed by Microsoft Word and ultimately signed off by a lawyer.

Work shape: Bounded Transactional. The skill applies a defined set of word-level edits to a DOCX and emits revised DOCX. It does not decide which edits to apply.