# XLSX Author

> Use when financial-services work requires produce a .xlsx file on disk (headless) instead of driving a live Excel workbook — for managed-agent sessions with no open Office app..

- Skill: `changhochien/xlsx-author` (Agent Skill)
- Install (CLI): `npx skillmds@latest add changhochien/xlsx-author`
- Raw SKILL.md: https://api.skillmd.com/api/skills/changhochien/xlsx-author/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Data & Analytics
- License: MIT
- Author: changhochien (https://skillmd.com/u/changhochien)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/changhochien/xlsx-author

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# xlsx-author

Use this skill when running **headless** (managed-agent / CMA mode) and you need to deliver an Excel workbook as a **file artifact** rather than editing a live workbook via `mcp__office__excel_*`.

## Output contract

- Write to `./out/<name>.xlsx`. Create `./out/` if it does not exist.
- Return the relative path in your final message so the orchestration layer can collect it.

## How to build the workbook

Write a short Python script and run it with Bash. Use `openpyxl`:

```python
from openpyxl import Workbook
from openpyxl.styles import Font, PatternFill

wb = Workbook()
ws = wb.active; ws.title = "Inputs"
ws["B2"] = "Revenue"; ws["C2"] = 1_250_000_000
ws["C2"].font = Font(color="0000FF")           # blue = hardcoded input
calc = wb.create_sheet("DCF")
calc["C5"] = "=Inputs!C2*(1+Inputs!C3)"        # black = formula
wb.save("./out/model.xlsx")
```

## Conventions (mirror `audit-xls`)

- **Blue / black / green.** Blue = hardcoded input, black = formula, green = link to another sheet/file.
- **No hardcodes in calc cells.** Every calculation cell is a formula; every input lives on an Inputs tab.
- **Named ranges** for any value referenced from a deck or memo.
- **Balance checks.** Include a Checks tab that ties (BS balances, CF ties to cash, etc.) and surfaces TRUE/FALSE.
- **One model per file.** Do not append to an existing workbook unless explicitly asked.

## When NOT to use

If `mcp__office__excel_*` tools are available (Cowork plugin mode), use those instead — they drive the user's live workbook with review checkpoints. This skill is the file-producing fallback for headless runs.

## Hermes Profile Notes
This skill was packaged from `pi-financial-services` source path `plugins/vertical-plugins/financial-analysis/skills/xlsx-author` for the Hermes financial-services profile. Use institutional data connectors first when available, cite sources, and stage outputs for qualified human review.


## Common Pitfalls
1. Do not present drafts as investment, legal, tax, or accounting advice.
2. Do not use web search as the primary source when an institutional MCP/data connector is available.
3. Do not execute transactions, contact clients, post to a ledger, or approve onboarding. Stage outputs for review.


## Verification Checklist
- [ ] Inputs, assumptions, dates, and currencies are explicit.
- [ ] Numbers tie across tables, models, decks, and memos.
- [ ] Sources are cited and institutional data is preferred where available.
- [ ] Output is labeled draft / for human review where appropriate.