excel-author

Produce an .xlsx file on disk using openpyxl. Follow the banker-grade conventions below so the model is auditable, flexible, and reviewable by someone other than the person who built it.

Adapted from Anthropic's xlsx-author and audit-xls skills in the anthropics/financial-services repo. The MCP / Office-JS / Cowork-specific branches of the originals are dropped — this skill assumes headless Python.

Output contract

• Write to ./out/<name>.xlsx. Create ./out/ if it does not exist.
• Return the relative path in your final message so downstream tools can pick it up.
• One logical model per file. Do not append to an existing workbook unless explicitly asked.

Setup

pip install "openpyxl>=3.0"

Core conventions (non-negotiable)