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.