Project Brief: office Skill

Created: 2026-01-12 Status: Ready for Planning

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Vision

A TypeScript-first skill for generating Office documents (DOCX, XLSX, PDF) that works everywhere - Claude Code CLI, Cloudflare Workers, and browsers. Simpler and more portable than Anthropic's official skills, installable via /plugin install office.

Problem/Opportunity

Anthropic published official document skills (docx, xlsx, pdf, pptx) but they're:

• Not installable as a plugin - requires manual setup
• Python-heavy - relies on openpyxl, pypdf, pandoc, LibreOffice
• Local execution only - can't run in Cloudflare Workers
• Comprehensive but complex - covers every edge case, ~500+ lines each

Opportunity: Create a streamlined, TypeScript-first alternative that:

• Installs with one command
• Works on edge runtimes (Cloudflare Workers)
• Covers 80% of use cases with 20% of the complexity

Target Audience

• Primary users: Developers building web apps that need document exports (invoices, reports, proposals)
• Secondary: Claude Code users wanting to create Office docs during development
• Scale: Part of claude-skills marketplace (60+ skills)
• Context: Production skill for our marketplace

Core Functionality (MVP)

1. DOCX Generation - Create Word documents

• Create documents with headings, paragraphs, tables, images
• Basic formatting (bold, italic, fonts, colors)
• Export to buffer/blob for download or storage
• Library: docx npm package (v9.x)

2. XLSX Generation - Create Excel spreadsheets

• Create workbooks with multiple sheets
• Cell formatting, formulas, column widths
• Export to buffer for download
• Library: xlsx (SheetJS) or exceljs for richer features

3. PDF Generation - Create and modify PDFs

• Create PDFs from scratch (text, images, shapes)
• Fill existing PDF forms
• Merge/split PDF documents
• Library: pdf-lib (v1.17.x)

4. HTML→PDF (Cloudflare Workers bonus)

• Convert HTML/CSS to PDF using Browser Rendering API
• Template-based document generation
• Requires: Cloudflare Browser Rendering binding

Out of Scope for MVP (defer to Phase 2):

• PowerPoint (PPTX) - adds complexity, can add later
• Tracked changes / redlining in DOCX - requires OOXML manipulation
• Formula recalculation/validation - requires LibreOffice
• OCR for scanned PDFs - requires Python/pytesseract
• Reading/parsing existing Office files (focus on creation first)

Tech Stack (Validated)

Component	Choice	Rationale
DOCX	docx npm v9.5+	Pure JS, Workers-compatible, well-maintained
XLSX	xlsx (SheetJS) v0.18+	Pure JS, universal runtime support
PDF	pdf-lib v1.17+	Explicitly supports Workers + browser
HTML→PDF	Cloudflare Browser Rendering	Native Cloudflare solution

Key Dependencies (all Workers-compatible):

• docx - 3.4 MB unpacked, ~1.2 MB minified
• xlsx - 7.5 MB unpacked, ~500 KB minified
• pdf-lib - 19.5 MB unpacked, ~500 KB minified

Research Findings

Similar Solutions Reviewed

Solution	Strengths	Weaknesses	Our Differentiation
Anthropic's official skills	Comprehensive, battle-tested	Python-heavy, not a plugin, local only	TS-first, plugin installable, Workers-compatible
tfriedel/claude-office-skills	Packages Anthropic's approach	Incomplete, attribution concerns	Original implementation, maintained
Individual npm libraries	Work well standalone	No Claude Code integration	Skill bundles with templates + patterns

Technical Validation

• docx in Workers: Confirmed compatible - pure JS, uses jszip internally
• pdf-lib in Workers: Explicitly documented as supporting Cloudflare Workers
• xlsx in Workers: Pure JS algorithms, no Node dependencies
• Browser Rendering: Official Cloudflare docs show HTML→PDF pattern
• Working example: worker-generate-invoice-pdf

Known Challenges

Challenge	Mitigation
Bundle size (~2-3MB total)	Tree-shaking, lazy loading, document which deps needed
No formula validation in XLSX	Document limitation, recommend manual verification
Complex DOCX editing	Out of scope for MVP, document as limitation
Browser Rendering requires paid plan	Document as optional enhancement

Scope Validation

Why Build This?

• Anthropic's skills aren't conveniently installable
• No existing skill covers server-side (Workers) document generation
• High demand use case (invoices, reports, exports)

Why This Approach?

• TypeScript aligns with our stack (Cloudflare, React, Vite)
• Pure JS libraries enable universal runtime support
• Focused scope = maintainable, high-quality skill

What Could Go Wrong?

1. Bundle size concerns - Mitigate with clear documentation on what to import
2. Missing features users expect - Clear scope documentation, Phase 2 roadmap
3. Library updates breaking things - Pin versions, test before updating

Estimated Effort

• MVP: ~4-6 hours (~4-6 minutes human time with Claude Code)
• Breakdown:
  • Research/templates: 1h (done in this exploration)
  • DOCX patterns + templates: 1-1.5h
  • XLSX patterns + templates: 1-1.5h
  • PDF patterns + templates: 1-1.5h
  • Workers examples: 0.5-1h
  • Testing + polish: 0.5h

Success Criteria (MVP)

• /plugin install office works from claude-skills marketplace
• Can create basic DOCX with headings, paragraphs, tables
• Can create basic XLSX with data, formulas, formatting
• Can create PDF with text, images, or fill forms
• All templates work in both Node.js AND Cloudflare Workers
• Documentation includes "Use when" scenarios and examples
• Skill follows claude-skills standards (YAML frontmatter, README, etc.)

Skill Structure

skills/office/
├── SKILL.md              # Main skill with patterns for all 3 formats
├── README.md             # Auto-trigger keywords
├── rules/
│   └── office.md         # Correction rules for common mistakes
├── templates/
│   ├── docx-basic.ts     # Word document template
│   ├── xlsx-basic.ts     # Excel spreadsheet template
│   ├── pdf-basic.ts      # PDF generation template
│   └── workers-pdf.ts    # Cloudflare Workers HTML→PDF example
├── references/
│   ├── docx-api.md       # Quick reference for docx npm
│   ├── xlsx-api.md       # Quick reference for SheetJS
│   └── pdf-lib-api.md    # Quick reference for pdf-lib
└── scripts/
    └── verify-deps.sh    # Check library versions

Next Steps

If proceeding:

1. Run /plan-project to generate IMPLEMENTATION_PHASES.md
2. Review phases and adjust
3. Start Phase 1 (skill scaffolding)

Phase 2 Roadmap (after MVP):

• Add PPTX generation
• Add template system (fill placeholders in existing docs)
• Add more complex DOCX features (headers/footers, TOC)
• Consider reading/parsing existing files

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Research References

• Anthropic Skills Repository
• docx npm package
• pdf-lib
• SheetJS (xlsx)
• Cloudflare Browser Rendering - PDF Generation
• worker-generate-invoice-pdf example
• tfriedel/claude-office-skills
• pdfjs-serverless for Workers