Claude Official Skill: XLSX — Spreadsheet Operations

What it is

This is an official Claude Code skill from Anthropic's skills repository for working with Excel spreadsheet files. It handles creating workbooks, writing formulas, generating charts, building pivot tables, and automating data analysis across XLSX, XLSM, and CSV formats.

The skill is designed for developers and analysts who use Claude Code and need to programmatically generate or manipulate spreadsheets without leaving the terminal.

How it saves time or tokens

Instead of manually writing openpyxl or xlsxwriter code, the skill provides Claude Code with the knowledge to handle spreadsheet operations directly. It understands Excel formula syntax, chart types, and formatting conventions. The estimated token cost is around 500 tokens per invocation.

How to use

1. Install via Claude Code:

claude skill install anthropics/skills/xlsx

1. Or manually copy the SKILL.md content to .claude/skills/xlsx/SKILL.md
2. The skill activates automatically when you ask Claude Code to work with spreadsheet files

Example

# Generated by Claude Code with xlsx skill
import openpyxl
from openpyxl.chart import BarChart, Reference

wb = openpyxl.Workbook()
ws = wb.active
ws.title = 'Sales Report'

# Headers and data
ws.append(['Month', 'Revenue', 'Costs'])
ws.append(['Jan', 50000, 30000])
ws.append(['Feb', 62000, 35000])
ws.append(['Mar', 58000, 32000])

# Add formula
ws['D1'] = 'Profit'
ws['D2'] = '=B2-C2'
ws['D3'] = '=B3-C3'
ws['D4'] = '=B4-C4'

# Add chart
chart = BarChart()
data = Reference(ws, min_col=2, max_col=4, min_row=1, max_row=4)
chart.add_data(data, titles_from_data=True)
ws.add_chart(chart, 'A6')

wb.save('sales_report.xlsx')

Related on TokRepo

• AI coding tools — development productivity skills
• Automation tools — data processing automation

Common pitfalls

• Forgetting to install the openpyxl dependency in your Python environment
• Opening large XLSX files in read-only mode to avoid memory issues
• Not handling formula calculation mode (formulas show raw text until opened in Excel)