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XLSX Author

AnthropicOfficialPublished by Anthropic

  • Skill
  • Tool integration
  • Documents and content
  • Apache-2.0
  • No issues found
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From the author

Produce a .xlsx file on disk (headless) instead of driving a live Excel workbook — for managed-agent sessions with no open Office app.
— the description by Anthropic

AutoGineer summary

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

xlsx-author provides a structured approach for AI agents to create .xlsx files directly on disk without requiring a live Excel application. Designed for headless or managed-agent environments, it ensures consistent formatting, formula-driven calculations, and professional modeling standards by leveraging Python and the openpyxl library.

What it does

  • Generates .xlsx files programmatically in headless environments
  • Enforces standardized color-coding for inputs, formulas, and links
  • Supports the creation of named ranges for referenced values
  • Facilitates the inclusion of balance check tabs for data validation
  • Outputs files to a designated directory for collection by orchestration layers

When to use it

  • When operating in headless or managed-agent modes
  • When you need to deliver a standalone Excel file artifact
  • When live Excel application integration tools are unavailable
  • When building financial or data models that require strict structural conventions

Advantages

  • Enables automated spreadsheet generation without GUI dependencies
  • Promotes clean modeling practices through enforced separation of inputs and formulas
  • Ensures consistent file structure and naming conventions
  • Allows for programmatic validation through built-in balance checks

Usage examples

“Create a financial model for a startup with revenue projections.”
The agent generates a model.xlsx file in the ./out/ directory, containing an Inputs tab with blue-coded hardcoded values and a DCF tab with black-coded formulas.
“Generate a budget spreadsheet with a balance check tab.”
The agent creates a workbook with an Inputs sheet and a Checks sheet that performs boolean validation on the budget totals.

Install

  1. Download the skill as a ZIP:

    https://autogineer.com/agent-skills/anthropics/xlsx-author/download

  2. Unzip it into the cross-client skills folder of your project:

    mkdir -p .agents/skills && unzip xlsx-author.zip -d .agents/skills

Documentation by Anthropic

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:

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.

Files

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 an MCP server, Needs Python

Security

No issues found by our static scan· No issues found

A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.

Attribution and licence

Published by
Anthropic
Publisher
Anthropic (Official)
Source
anthropics/financial-services · plugins/agent-plugins/pitch-agent/skills/xlsx-author · commit 6056506
Licence
Apache License 2.0 (redistribution allowed)
  • LICENSE (added by AutoGineer from LICENSE)
  • ATTRIBUTION.md (written by AutoGineer)
Synced
Also distributed in
anthropics/financial-services, anthropics/financial-services, anthropics/financial-services, anthropics/financial-services, anthropics/financial-services, anthropics/financial-services, anthropics/financial-services, anthropics/financial-services

AutoGineer is not affiliated with or endorsed by Anthropic or Anthropic.

Download ZIP

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