# XLSX

> Create polished Excel workbooks for budgets, trackers, tables, and explicit .xlsx spreadsheet requests.

- Skill: `gabrielmoreira/xlsx-13` (Agent Skill)
- Install (CLI): `npx skillmds@latest add gabrielmoreira/xlsx-13`
- Raw SKILL.md: https://api.skillmd.com/api/skills/gabrielmoreira/xlsx-13/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: gabrielmoreira (https://skillmd.com/u/gabrielmoreira)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/gabrielmoreira/xlsx-13

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# XLSX

Create the requested workbook in `/workspace` with the preinstalled
`xlsxwriter` and `openpyxl` packages. Never install or download dependencies.
Use XlsxWriter for new workbooks because it can write explicit formula caches
that verification and the browser grid require.

## Authoring rules

- Prefer one clear sheet purpose per worksheet. Name sheets for the user, not
  `Sheet1` / `Sheet2`, unless the request is a blank template.
- Set column widths deliberately. Freeze header rows when tables are scrolled.
- Style headers once (bold, fill, borders) and reuse the style objects. Prefer
  number formats (`#,##0.00`, `0%`, dates) over pre-formatted strings.
- Write formulas with **both** the formula string and a computed cached value:
  `worksheet.write_formula("B2", "=A2*1.1", cell_format, 110)`. Verification
  rejects formula cells that lack a cached result, and the in-browser grid
  shows the cache rather than recalculating.
- Also call `workbook.set_calc_mode("auto")` (or the equivalent recalculation
  on open) so Excel/LibreOffice recompute when the file is opened.
- Never leave Excel error literals (`#DIV/0!`, `#REF!`, `#VALUE!`, `#N/A`, …)
  as cached results. Fix the formula or the inputs instead.
- Keep workbooks under the verification cell ceiling (100 000 cells). Prefer
  compact tables over giant empty ranges.
- Charts, pivot tables, macros, and VBA are out of scope for this skill. Stick
  to values, formulas, formats, panes, and multiple sheets.

## Revisions

Start an in-place revision with `load_artifact_for_revision`. Open
`primary_path` with `openpyxl` using `data_only=False`, edit that current
workbook directly, and write the revision to `expected_output_path`. Preserve
unaffected worksheets, formulas, formatting, panes, validation, links, and
workbook settings. Use `markdown_path` as textual context, not as a replacement
workbook. Do not use vision to reconstruct workbook contents.

If the workbook contains formulas, saving with `openpyxl` is not the final
step: run headless LibreOffice on a temporary copy and place the recalculated
XLSX at `expected_output_path` before verification. This refreshes formula
caches for verification and the browser grid. Use distinct temporary input and
conversion-output paths so LibreOffice never overwrites its own input. Check
the command's exit status and confirm the recalculated file exists. The
conversion command is
`libreoffice --headless --convert-to xlsx --outdir <recalc-dir> <temporary.xlsx>`;
move its output to `expected_output_path`.

Save the verified revision with the returned `artifact_id` and
`expected_generation`. A changed title, filename, or design is still the same
artifact unless the user explicitly asks for a separate copy.

## Verify and save

Call `verify_artifact(path=output_path, format="xlsx")`. Spreadsheet verification is
structural only: there is no PDF preview and no vision pass. Warnings are
advisory. If it reports blocking findings, fix all blockers together,
regenerate once at the same output path, and reverify. If a blocker remains,
stop and explain it instead of entering another automatic rewrite loop.

Then call `save_artifact(path=output_path, title="...",
markdown_representation="...")`. Working files may use any paths; no source
file, preview file, or matching filename stem is part of the publication
contract. The Markdown representation must faithfully summarize the workbook's
sheets, column meanings, and key figures for accessibility and search.