Excel Spreadsheet Wizard

Excel Spreadsheet Wizard builds real .xlsx workbooks programmatically — with formulas that calculate, conditional formatting that triggers, named ranges that resolve, and chart-ready data layouts. It is aimed at developers and analysts who need to hand off a finished spreadsheet (a budget model, a KPI report, a reconciliation sheet) rather than a CSV dump, and who are tired of debugging #REF! and #NAME? errors after the fact.

When to use it

• You need a recurring report (monthly close, cohort retention, commission run) emitted as a styled workbook.
• You're turning a query result or JSON payload into a deliverable with subtotals, a pivot summary, and a chart.
• You want a financial model where downstream cells recalculate when inputs change — not pre-computed static values.
• You need output that opens cleanly in Excel, Google Sheets, and Numbers without "repair" prompts.

How it works

Under the hood the skill writes workbooks with the OpenPyXL engine and validates them before returning. Key capabilities:

• Formulas written as strings into cells (ws["D2"] = "=SUM(B2:C2)"), with relative/absolute references resolved against the actual data range so they don't drift or break.
• Conditional formatting via ColorScaleRule, CellIsRule, and FormulaRule (data bars, color scales, highlight-greater-than, etc.).
• Named ranges registered through DefinedName so formulas read =SUM(Revenue) instead of opaque coordinates.
• Charts (BarChart, LineChart, PieChart) wired to Reference ranges.
• Pivot-style summaries generated as grouped/aggregated sheets (true native pivot caches are limited in the .xlsx spec, so the skill emits a refreshable summary table plus the source range).

After generation it loads the file back, recalculates with a formula evaluator, and flags any cell resolving to an error before you ship it.

Usage

curl -fsSL --create-dirs -o ~/.claude/skills/excel-spreadsheet-wizard/SKILL.md https://claudeskil.com/skills/excel-spreadsheet-wizard/SKILL.md

# then, in a session:
> Build sales_report.xlsx from this CSV. Add a "Total" column
> (=quantity*unit_price), a color scale on the Total column,
> a named range "Revenue" over it, and a bar chart of revenue
> by region on a second sheet.

You can also point it at existing data: "open Q3.xlsx, add a conditional-format rule flagging margins below 20% in red, and a summary pivot by product line."

Tips & gotchas

• Formulas are stored, not evaluated by the writer. Excel/Sheets computes them on open; the skill's validator pre-checks them, but a blank cell on first open usually means the app hasn't recalculated — press F9 or enable auto-calc.
• Cross-sheet references need quoted sheet names when they contain spaces: ='Raw Data'!A2. Ask the skill to handle quoting and it will.
• Numbers is the strictest reader. Exotic conditional-format icon sets may degrade there; stick to color scales and data bars for full cross-app fidelity.
• Pivots aren't live pivot tables — they're aggregated summary sheets. If you need a refreshable native PivotTable, say so and keep the source range intact.

FAQ

Will it overwrite my existing workbook? No — it writes to a new path unless you explicitly ask it to edit a file in place.

Can it preserve my existing styles and macros? Cell styles and data are preserved on edits. VBA macros require .xlsm; tell it to keep macros and it will use the macro-enabled format.

Does it support multiple sheets and formulas across them? Yes — multi-sheet workbooks with inter-sheet formulas and named ranges spanning sheets are fully supported.