What it is
The xlsx skill guides an agent through reading, creating, editing, cleaning and converting spreadsheet files whenever a spreadsheet is the primary input or output. It prescribes openpyxl for formulas and formatting, pandas for bulk data, and markitdown for quick looks. A mandatory recalculation step with scripts/recalc.py (LibreOffice) reports formula errors. It also sets rules for output quality and financial-model conventions.
Who it's for
- Users who need spreadsheet files created, edited, cleaned or converted by an AI agent
- Analysts building formula-driven workbooks or financial models
- Anyone restructuring messy tabular data (malformed rows, misplaced headers, junk data) into proper spreadsheets
Requirements
Requirements
- openpyxl, pandas and markitdown (preinstalled; install only if an import fails or the command is missing)
- LibreOffice (soffice), auto-configured via scripts/office/soffice.py
- Python, to run scripts/recalc.py
- The deliverable must be a spreadsheet file
Setup
Recalculate a workbook with formulas
Run recalc.py after writing formulas, because openpyxl stores no cached values. The file is rewritten in place and JSON is returned with status, total_formulas, total_errors and error_summary. The timeout defaults to 30 seconds.
bashpython scripts/recalc.py output.xlsx [timeout_seconds] # default 30
Examples
Write a formula instead of a computed value
pythonsheet['B10'] = '=SUM(B2:B9)'What it does: The skill requires formulas rather than hardcoded Python-computed results, so the sheet recalculates when inputs change.
Quote sheet names with spaces
python='Assumptions Inputs'!$B$5What it does: A cross-sheet reference to a sheet name containing a space must be quoted, or it evaluates to #VALUE!.
Use the _xlfn. prefix for post-2007 functions
text_xlfn.TEXTJOIN, _xlfn.CONCAT, _xlfn.IFS, _xlfn.SWITCH, _xlfn.MAXIFS, _xlfn.MINIFSWhat it does: These six work only with the prefix; written bare they yield #NAME?.
Quick look at a sheet
bashmarkitdown file.xlsxWhat it does: Outputs a ## SheetName section per sheet and reads .xlsm too. It gives no cell coordinates, so don't plan edits from it.
Pros & cons
Pros
- Pro:Mandatory recalc step with JSON error reporting catches formula errors before delivery
- Pro:Detailed openpyxl gotchas (data_only, merged cells, keep_vba, quoted sheet names) prevent common silent mistakes
- Pro:Clear formula guidance avoids functions LibreOffice cannot evaluate, such as XLOOKUP and FILTER
- Pro:Includes financial-model conventions for colors, number formats and assumption handling
Cons
- Con:Cannot use XLOOKUP, XMATCH, SORT, FILTER, UNIQUE or SEQUENCE; sorting and filtering must be done in Python
- Con:A clean recalc only proves formulas evaluate, not that they are correct, so manual checks are needed
- Con:Re-saving workbooks with external links via openpyxl and recalculating loses those links; recalc.py refuses unless --force is used
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