Xlsx

This handles everything spreadsheet related: creating financial models from scratch, analyzing existing data, and modifying templates while preserving their formulas and formatting. It enforces zero formula errors through mandatory recalculation with LibreOffice, and ships with opinionated standards for financial modeling (blue text for inputs, black for formulas, specific number formatting). The documentation is thorough on formula construction and includes a recalc.py script that catches errors like #REF! and #DIV/0! before you share anything. Useful if you're building projection models or need Claude to actually understand Excel conventions instead of just dumping CSV data into cells. The color coding rules alone will save arguments with finance teams.

skills.sh installs: 238
GitHub stars: 476
last updated: Aug 21, 2026

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Install

$ npx -y skills add aiskillstore/marketplace --skill xlsx --agent claude-code

Installs into .claude/skills of the current project.

Files

Requirements for Outputs

All Excel files

Zero Formula Errors

Every Excel model MUST be delivered with ZERO formula errors (#REF!, #DIV/0!, #VALUE!, #N/A, #NAME?)

Preserve Existing Templates (when updating templates)

Study and EXACTLY match existing format, style, and conventions when modifying files
Never impose standardized formatting on files with established patterns
Existing template conventions ALWAYS override these guidelines

Financial models

Color Coding Standards

Unless otherwise stated by the user or existing template

Industry-Standard Color Conventions

Blue text (RGB: 0,0,255): Hardcoded inputs, and numbers users will change for scenarios
Black text (RGB: 0,0,0): ALL formulas and calculations
Green text (RGB: 0,128,0): Links pulling from other worksheets within same workbook
Red text (RGB: 255,0,0): External links to other files
Yellow background (RGB: 255,255,0): Key assumptions needing attention or cells that need to be updated