excel-automation

An agent skill by daymade, from daymade/claude-code-skills. Tags: automation, data, macos, office, spreadsheets.

What it does

Create, parse, and control Excel files on macOS. Professional formatting with openpyxl, complex xlsm parsing with stdlib zipfile+xml for investment bank financial models, and Excel window control via AppleScript. Use when creating formatted Excel reports, parsing financial models that openpyxl cannot handle, or automating Excel on macOS.

Install

With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:

npx skills add daymade/claude-code-skills --skill excel-automation

Or copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):

git clone --depth 1 https://github.com/daymade/claude-code-skills
cp -r claude-code-skills/daymade-docs/excel-automation ~/.claude/skills/excel-automation

Safety box score

Grade B, low risk: 18 of 100 risk points, rated 2026-10-20. The grade rates what the skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. How the score works.

This skill creates and parses Excel workbooks locally, and can also drive Microsoft Excel on macOS through AppleScript. The main risks are running bundled Python scripts on user-supplied workbook paths, potentially fetching `openpyxl` at runtime, and changing the active Excel window during UI automation.

Category levels, from 0 (none) to 3 (high)
Category	Level	Why
Code & shell execution	2 (moderate)	The skill explicitly runs local code via `uv run ... scripts/*.py` and sends AppleScript to Excel (`osascript -e 'tell application "Microsoft Excel" to activate'`), so it can execute code against provided files.
Network access	1 (low)	It declares `dependencies = ["openpyxl"]` and instructs `uv run --with openpyxl`, which can contact a package index and download that library if it is not already present.
Filesystem reach	1 (low)	The scripts read and rewrite workbook files with `zf.extractall(tmp)` and `wb.save(output_path)`, but the visible blast radius stays within the workbook paths the caller supplies.
Secrets & credentials	0 (none)	No code or instructions here read browser sessions, keychains, `.env` files, tokens, or passwords.
Privilege & persistence	0 (none)	There is no sudo use, global install, service registration, login-item setup, or shell/OS setting change in the files.
Instruction hijack surface	0 (none)	I found no prompt-injection content such as instructions to ignore safeguards, hide behavior, or fetch remote instructions.
Irreversible actions	0 (none)	The skill edits and inspects Excel files only; it does not send messages, publish, pay, deploy, or delete external resources.
Transparency	1 (low)	The repo is readable, but it relies on the external `openpyxl` package rather than bundling all workbook logic in-tree.

Before installing

Read `SKILL.md` and both scripts: they will execute local Python and AppleScript.
If you care about offline installs, preinstall `openpyxl` and run the scripts once with network disabled.
Test on a scratch workbook first to confirm the output path and any AppleScript UI actions are acceptable.

Rated 2026-10-20 by an automated review of 5 files from the skill's repository.

Source

Repository: daymade/claude-code-skills (all skills from this repository)
Path: daymade-docs/excel-automation/SKILL.md
Branch: main
Updated: 2026-09-20

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