Let AI Truly Excel at Writing Excel: Detailed Explanation of Anthropic's Official xlsx Skill

xlsx is an official Anthropic Agent Skill dedicated to handling reading and writing of spreadsheet files such as .xlsx/.csv, formula modeling and data cleaning, and also serves as the implementation reference behind Claude's document capabilities. This article introduces its core capabilities (division of labor among openpyxl/pandas/markitdown, formula recalculation via recalc.py, and financial model specifications), as well as the installation, activation methods and typical usage scenarios in Cursor, Claude Code and Claude.ai, to help developers enable AI to directly deliver auditable spreadsheets.