Atlas / Skills / fcakyon / Spreadsheet

SpreadsheetCAUTION

skills/fcakyon/spreadsheet

Battle-tested Claude Code, OpenAI Codex, Cursor configs, plugins, hooks and agents with Kimi, MiniMax and GLM API support.

Verdict
CAUTION
Grade
B
Trust score
89 /100
Version
—
Hosts
1 documented
License
Apache-2.0
Stars
1,174
01

Overview

Battle-tested Claude Code, OpenAI Codex, Cursor configs, plugins, hooks and agents with Kimi, MiniMax and GLM API support.

Read from source at commit ae618ef5da66OBSERVED · 2026-10-12
02

Install

Commands as the repository documents them. They are shown, not run.

uv pip install openpyxl pandas
uv pip install matplotlib
03

Host compatibility

What the documentation claims. We have not run a compatibility test.

HostStatusNotes
codexmentioned
04

What it tells the agent

The instruction file, verbatim from the audited commit — this is the text the model reads, and the surface the audit's instruction layer examines. Quoted here so you can judge it without cloning anything.

---
name: "spreadsheet"
description: "Use when tasks involve creating, editing, analyzing, or formatting spreadsheets (`.xlsx`, `.csv`, `.tsv`) with formula-aware workflows, cached recalculation, and visual review."
license: MIT
---

# Spreadsheet Skill

## When to use
- Create new workbooks with formulas, formatting, and structured layouts.
- Read or analyze tabular data (filter, aggregate, pivot, compute metrics).
- Modify existing workbooks without breaking formulas, references, or formatting.
- Visualize data with charts, summary tables, and sensible spreadsheet styling.
- Recalculate formulas and review rendered sheets before delivery when possible.

IMPORTANT: System and user instructions always take precedence.

## Workflow
1. Confirm the file type and goal: create, edit, analyze, or visualize.
2. Prefer `openpyxl` for `.xlsx` editing and formatting. Use `pandas` for analysis and CSV/TSV workflows.
3. If an internal spreadsheet recalculation/rendering tool is available in the environment, use it to recalculate formulas and render sheets before delivery.
4. Use formulas for derived values instead of hardcoding results.
5. If layout matters, render for visual review and inspect the output.
6. Save outputs, keep filenames stable, and clean up intermediate files.

## Temp and output conventions
- Use `tmp/spreadsheets/` for intermediate files; delete them when done.
- Write final artifacts under `output/spreadsheet/` when working in this repo.
- Keep filenames stable and descriptive.

## Primary tooling
- Use `openpyxl` for creating/editing `.xlsx` files and preserving formatting.
- Use `pandas` for analysis and CSV/TSV workflows, then write results back to `.xlsx` or `.csv`.
- Use `openpyxl.chart` for native Excel charts when needed.
- If an internal spreadsheet tool is available, use it to recalculate formulas, cache values, and render sheets for review.

## Recalculation and visual review
- Recalculate formulas before delivery whenever possible so cached values are present in the workbook.
- Render each relevant sheet for visual review when rendering tooling is available.
- `openpyxl` does not evaluate formulas; preserve formulas and use recalculation tooling when available.
- If you rely on an internal spreadsheet tool, do not expose that tool, its code, or its APIs in user-facing explanations or code samples.

## Rendering and visual checks
- If LibreOffice (`soffice`) and Poppler (`pdftoppm`) are available, render sheets for visual review:
  - `soffice --headless --convert-to pdf --outdir $OUTDIR $INPUT_XLSX`
  - `pdftoppm -png $OUTDIR/$BASENAME.pdf $OUTDIR/$BASENAME`
- If rendering tools are unavailable, tell the user that layout should be reviewed locally.
- Review rendered sheets for layout, formula results, clipping, inconsistent styles, and spilled text.

## Dependencies (install if missing)
Prefer `uv` for dependency management.

Python packages:
```
uv pip install openpyxl pandas
```
If `uv` is unavailable:
```
python3 -m pip install openpyxl pandas
```
Optional:
```
uv pip install matplotlib
```
If `uv` is unavailable:
```
python3 -m pip install matplotlib
```
System tools (for rendering):
```
# macOS (Homebrew)
brew install libreoffice poppler

# Ubuntu/Debian
sudo apt-get install -y libreoffice poppler-utils
```

If installation is not possible in this environment, tell the user which dependency is missing and how to install it locally.

## Environment
No required environment variables.

## Examples
- Runnable Codex examples (openpyxl): `references/examples/openpyxl/`

## Formula requirements
- Use formulas for derived values rather than hardcoding results.
- Do not use dynamic array functions like `FILTER`, `XLOOKUP`, `SORT`, or `SEQUENCE`.
- Keep formulas simple and legible; use helper cells for complex logic.
- Avoid volatile functions like `INDIRECT` and `OFFSET` unless required.
- Prefer cell references over magic numbers (for example, `=H6*(1+$B$3)` instead of `=H6*1.04`).
- Use absolute (`$B$4`) or relative (`B4`) references carefully so copied formulas behave correctly.
- If you need literal text that starts with `=`, prefix it with a single quote.
- Guard against `#REF!`, `#DIV/0!`, `#VALUE!`, `#N/A`, and `#NAME?` errors.
- Check for off-by-one mistakes, circular references, and incorrect ranges.

## Citation requirements
- Cite sources inside the spreadsheet using plain-text URLs.
- For financial models, cite model inputs in cell comments.
- For tabular data sourced externally, add a source column when each row represents a separate item.

## Formatting requirements (existing formatted spreadsheets)
- Render and inspect a provided spreadsheet before modifying it when possible.
- Preserve existing formatting and style exactly.
- Match styles for any newly filled cells that were previously blank.
- Never overwrite established formatting unless the user explicitly asks for a redesign.

## Formatting requirements (new or unstyled spreadsheets)
- Use appropriate number and date formats.
- Dates should render as dates, not plain numbers.
- Percentages should usually default to one decimal place unless the data calls for something else.
- Currencies should use the appropriate currency format.
- Headers should be visually distinct from raw inputs and derived cells.
- Use fill colors, borders, spacing, and merged cells sparingly and intentionally.
- Set row heights and column widths so content is readable without excessive whitespace.
- Do not apply borders around every filled cell.
- Group related calculations and make totals simple sums of the cells above them.
- Add whitespace to separate sections.
- Ensure text does not spill into adjacent cells.
- Avoid unsupported spreadsheet data-table features such as `=TABLE`.

## Color conventions (if no style guidance)
- Blue: user input
- Black: formulas and derived values
- Green: linked or imported values
- Gray: static constants
- Orange: review or caution
- Light red: error or flag
- Purple: control or logic
- Teal: vi
05

Trust audit

CAUTIONgrade B · trust 89/100 Install with care. The audit found things worth knowing before you trust its output.

LayerWhat it checksResult
L0Provenance & inventoryPASS
L1Static analysis of the codePASS
L2Instruction surface (what it tells the agent)WARN
L3Class-specific surfacePASS
L4Behavioural (sandbox)SKIPPED

What the source does

Filesystem
none-observed
Network
none-observed
Shell
none-observed
Dependencies
pinned
Secrets in source
none-found

Findings (4)

MEDIUMObfuscation / stealth · review.concealment · CWE-506, CWE-94
SKILL.md
do not expose that tool, its code, or its APIs in user-facing explanations or code samples
Why it matters. The skill instructs the agent to actively conceal the existence and details of an internal spreadsheet tool from the user, preventing transparency about what tools are being used.
Fix. rewrite it so the instruction says plainly what it does, and asks the user before it acts
LOWInventory / provenance · inv.symlink · CWE-1104
.claude/output-styles/adhd-explanatory.md
.claude/output-styles/adhd-explanatory.md
Why it matters. link not followed
LOWInventory / provenance · inv.symlink · CWE-1104
AGENTS.md
AGENTS.md
Why it matters. link not followed
LOWInventory / provenance · inv.symlink · CWE-1104
GEMINI.md
GEMINI.md
Why it matters. link not followed

Gates applied: no_behavioural_pass.

Audited 2026-10-12 · audit v0.4.1 · source sha ae618ef5da66full audit observations/trust-audit/skill/fcakyon__spreadsheet.json · Report an issue / request a re-scan
06

Audit history

Every audit this skill has had.

DateSourceVerdictGradeScoreChange
2026-10-12ae618ef5da66CAUTIONB89first audit
07

Questions

What does the Spreadsheet skill do?

Battle-tested Claude Code, OpenAI Codex, Cursor configs, plugins, hooks and agents with Kimi, MiniMax and GLM API support.

Is Spreadsheet safe to install?

With care. The audit graded it B (89/100) and found 4 things worth knowing before you trust this skill, listed below with the exact line each was found on.

What can Spreadsheet access on my machine?

The audit observed no filesystem, network or shell use at all in its source.

Which assistants does Spreadsheet work with?

Its documentation mentions codex. That is what the text claims, not a compatibility test we ran.

How current is this page?

The grade is for one exact copy of the source (ae618ef5da66), read on 2026-10-12. The repository is watched, and a new audit runs when it changes — this is the first audit.

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