Note: This repository contains Anthropic's implementation of skills for Claude. For information about the Agent Skills standard, see agentskills.io.

Skills

Skills are folders of instructions, scripts, and resources that Claude loads dynamically to improve performance on specialized tasks. Skills teach Claude how to complete specific tasks in a repeatable way, whether that's creating documents with your company's brand guidelines, analyzing data using your organization's specific workflows, or automating personal tasks.

For more information, check out:

About This Repository

This repository contains skills that demonstrate what's possible with Claude's skills system. These skills range from creative applications (art, music, design) to technical tasks (testing web apps, MCP server generation) to enterprise workflows (communications, branding, etc.).

Each skill is self-contained in its own folder with a SKILL.md file containing the instructions and metadata that Claude uses. Browse through these skills to get inspiration for your own skills or to understand different patterns and approaches.

Many skills in this repo are open source (Apache 2.0). We've also included the document creation & editing skills that power Claude's document capabilities under the hood in the skills/docx, skills/pdf, skills/pptx, and skills/xlsx subfolders. These are source-available, not open source, but we wanted to share these with developers as a reference for more complex skills that are actively used in a production AI application.

Disclaimer

These skills are provided for demonstration and educational purposes only. While some of these capabilities may be available in Claude, the implementations and behaviors you receive from Claude may differ from what is shown in these skills. These skills are meant to illustrate patterns and possibilities. Always test skills thoroughly in your own environment before relying on them for critical tasks.

Skill Sets

./skills: Skill examples for Creative & Design, Development & Technical, Enterprise & Communication, and Document Skills
./spec: The Agent Skills specification
./template: Skill template

Try in Claude Code, Claude.ai, and the API

Claude Code

You can register this repository as a Claude Code Plugin marketplace by running the following command in Claude Code:

/plugin marketplace add anthropics/skills

Then, to install a specific set of skills:

Select Browse and install plugins
Select anthropic-agent-skills
Select document-skills or example-skills
Select Install now

Alternatively, directly install either Plugin via:

/plugin install document-skills@anthropic-agent-skills
/plugin install example-skills@anthropic-agent-skills

After installing the plugin, you can use the skill by just mentioning it. For instance, if you install the document-skills plugin from the marketplace, you can ask Claude Code to do something like: "Use the PDF skill to extract the form fields from path/to/some-file.pdf"

Claude.ai

These example skills are all already available to paid plans in Claude.ai.

To use any skill from this repository or upload custom skills, follow the instructions in Using skills in Claude.

Claude API

You can use Anthropic's pre-built skills, and upload custom skills, via the Claude API. See the Skills API Quickstart for more.

Creating a Basic Skill

Skills are simple to create - just a folder with a SKILL.md file containing YAML frontmatter and instructions. You can use the template-skill in this repository as a starting point:

---
name: my-skill-name
description: A clear description of what this skill does and when to use it
---

# My Skill Name

[Add your instructions here that Claude will follow when this skill is active]

## Examples
- Example usage 1
- Example usage 2

## Guidelines
- Guideline 1
- Guideline 2

The frontmatter requires only two fields:

name - A unique identifier for your skill (lowercase, hyphens for spaces)
description - A complete description of what the skill does and when to use it

The markdown content below contains the instructions, examples, and guidelines that Claude will follow. For more details, see How to create custom skills.

Partner Skills

Skills are a great way to teach Claude how to get better at using specific pieces of software. As we see awesome example skills from partners, we may highlight some of them here:

Notion - Notion Skills for Claude

docx

name: docx description: "Use this skill whenever the user wants to create, read, edit, or manipulate Word documents (.docx files) or Word templates (.dotx files). Triggers include: any mention of 'Word doc', 'word document', '.docx', '.dotx', or requests to produce professional documents with formatting like tables of contents, headings, page numbers, or letterheads. Also use when extracting or reorganizing content from .docx or .dotx files, inserting or replacing images in documents, performing find-and-replace in Word files, working with tracked changes or comments, or converting content into a polished Word document. If the user asks for a 'report', 'memo', 'letter', 'template', or similar deliverable as a Word or .docx file, use this skill. Do NOT use for PDFs, spreadsheets, Google Docs, or general coding tasks unrelated to document generation." license: Proprietary. LICENSE.txt has complete terms

DOCX creation, editing, and analysis

A .docx is a ZIP archive of XML files. Choose your approach by task:

Task	Approach
Create a new document	Write a `docx` (npm) script — see gotchas below
Edit an existing document	`unzip` → edit `word/document.xml` → `zip` (docx-js cannot open existing files)
Read content	`pandoc -t markdown file.docx`

Script paths below are relative to this skill's directory.

Creating with docx-js — gotchas

docx is preinstalled — do not run npm install first; write the script and require('docx') directly. Only if that require fails: npm install docx. The model knows the API; these are the footguns:

Page size defaults to A4. For US Letter set page: { size: { width: 12240, height: 15840 } } (DXA; 1440 = 1″).
Landscape: pass portrait dimensions and orientation: PageOrientation.LANDSCAPE — docx-js swaps width/height internally.
Tables need dual widths: set columnWidths on the table AND width on every cell, both in WidthType.DXA (PERCENTAGE breaks in Google Docs). Column widths must sum to the table width.
Table shading: use ShadingType.CLEAR, never SOLID (renders black).
Lists: never insert • literally; use a numbering config with LevelFormat.BULLET.
ImageRun requires type: ("png", "jpg", …).
PageBreak must be inside a Paragraph.
Never use \n — use separate Paragraph elements.
TOC: headings must use built-in HeadingLevel.*; custom heading styles need outlineLevel set or they won't appear.
Don't use a table as a horizontal rule — use a paragraph bottom border instead.
Dot-leader / right-aligned-on-same-line: use PositionalTab (alignment: PositionalTabAlignment.RIGHT, leader: PositionalTabLeader.DOT) inside a TextRun, not literal . or space padding.

Verify the output

After writing a .docx, render it and look at it:

python scripts/office/soffice.py --headless --convert-to pdf output.docx
pdftoppm -jpeg -r 100 output.pdf page
ls page-*.jpg   # then Read the images

pdftoppm zero-pads page numbers to the width of the page count (page-01.jpg…page-12.jpg).

Editing existing documents

Legacy .doc files must be converted first: python scripts/office/soffice.py --headless --convert-to docx file.doc.

unzip -q doc.docx -d unpacked/
find unpacked -type l -delete   # strip symlink entries — docx from external parties is untrusted
python scripts/merge_runs.py unpacked/   # coalesce fragmented runs so text is findable
# edit unpacked/word/document.xml in place — do NOT reformat or pretty-print
(cd unpacked && rm -f ../out.docx && zip -Xr ../out.docx .)
python scripts/office/validate.py out.docx --original doc.docx   # XSD checks; --auto-repair fixes common issues
# redlining? add --author "<the name you redlined under>" to check every edit is tracked

Word splits text across many <w:r> runs (revision ids, spell-check markers), so a phrase you can see in the document often doesn't exist as a contiguous string in the XML. merge_runs.py merges adjacent identically-formatted runs in word/document.xml without changing content or rendering; it also accepts a .docx directly (python scripts/merge_runs.py doc.docx -o merged.docx).

Tracked changes: when redlining, validate with --author "<the name you redlined under>" (needs --original) — it reports any text you changed without a <w:ins>/<w:del> around it, which is easy to do by accident and invisible in the accepted view. Wrap runs in <w:ins>/<w:del> with w:id, w:author, w:date attributes. Inside <w:del>, the text element is <w:delText>, not <w:t>. A deleted paragraph mark (<w:pPr><w:rPr><w:del w:id=".." w:author=".." w:date=".."/></w:rPr></w:pPr>) means "merge this paragraph into the next" — so deleting a paragraph outright is that plus a <w:del> around every run. The <w:del/> must come before the rPr's other children; their order is schema-enforced.

To produce a clean copy with all tracked changes accepted: python scripts/accept_changes.py in.docx out.docx.

Accepting a deleted paragraph mark should join that paragraph to the one below it, so a paragraph whose runs are all deleted vanishes. Word does this; accept_changes.py and pandoc --track-changes=accept don't always. Both fail the same way — they strip the deleted text but leave the emptied paragraph behind, which reads as a stray empty bullet when it was auto-numbered:

pandoc --track-changes=accept never joins the paragraphs.
accept_changes.py (LibreOffice) joins them correctly, except when the deleted paragraph is followed by an empty spacer paragraph.

An empty bullet in either view is an artifact of that view, not a defect in the document. Check paragraph deletions in the XML.

Comments

Comments require six cross-linked files. Use the helper — directory mode when you'll also be editing document.xml (saves an unzip/rezip cycle), .docx-direct mode otherwise:

# Against an already-unpacked directory (preferred when also placing markers)
python scripts/comment.py unpacked/ "Fees & expenses cap is too low"
python scripts/comment.py unpacked/ "Agreed" --parent 0

# Against a .docx directly
python scripts/comment.py contract.docx "This cap is too low" -o annotated.docx

The script writes comments.xml, commentsExtended.xml, commentsIds.xml, commentsExtensible.xml, the relationships, and the content-type overrides. Comment IDs are auto-assigned. It then prints the <w:commentRangeStart>/<w:commentRangeEnd>/<w:commentReference> snippet to add to word/document.xml so the comment anchors to specific text — until you place those markers, the comment exists but is not visible.

Dependencies

docx (npm, preinstalled — install only if require('docx') fails) · pandoc · LibreOffice (soffice) · pdftoppm (Poppler)

pdf

name: pdf description: Use this skill whenever the user wants to do anything with PDF files. This includes reading or extracting text/tables from PDFs, combining or merging multiple PDFs into one, splitting PDFs apart, rotating pages, adding watermarks, creating new PDFs, filling PDF forms, encrypting/decrypting PDFs, extracting images, and OCR on scanned PDFs to make them searchable. If the user mentions a .pdf file or asks to produce one, use this skill. license: Proprietary. LICENSE.txt has complete terms

PDF Processing Guide

Overview

This guide covers essential PDF processing operations using Python libraries and command-line tools. For advanced features, JavaScript libraries, and detailed examples, see REFERENCE.md. If you need to fill out a PDF form, read FORMS.md and follow its instructions.

Quick Start

from pypdf import PdfReader, PdfWriter

# Read a PDF
reader = PdfReader("document.pdf")
print(f"Pages: {len(reader.pages)}")

# Extract text
text = ""
for page in reader.pages:
    text += page.extract_text()

Python Libraries

pypdf - Basic Operations

Merge PDFs

from pypdf import PdfWriter, PdfReader

writer = PdfWriter()
for pdf_file in ["doc1.pdf", "doc2.pdf", "doc3.pdf"]:
    reader = PdfReader(pdf_file)
    for page in reader.pages:
        writer.add_page(page)

with open("merged.pdf", "wb") as output:
    writer.write(output)

Split PDF

reader = PdfReader("input.pdf")
for i, page in enumerate(reader.pages):
    writer = PdfWriter()
    writer.add_page(page)
    with open(f"page_{i+1}.pdf", "wb") as output:
        writer.write(output)

Extract Metadata

reader = PdfReader("document.pdf")
meta = reader.metadata
print(f"Title: {meta.title}")
print(f"Author: {meta.author}")
print(f"Subject: {meta.subject}")
print(f"Creator: {meta.creator}")

Rotate Pages

reader = PdfReader("input.pdf")
writer = PdfWriter()

page = reader.pages[0]
page.rotate(90)  # Rotate 90 degrees clockwise
writer.add_page(page)

with open("rotated.pdf", "wb") as output:
    writer.write(output)

pdfplumber - Text and Table Extraction

Extract Text with Layout

import pdfplumber

with pdfplumber.open("document.pdf") as pdf:
    for page in pdf.pages:
        text = page.extract_text()
        print(text)

Extract Tables

with pdfplumber.open("document.pdf") as pdf:
    for i, page in enumerate(pdf.pages):
        tables = page.extract_tables()
        for j, table in enumerate(tables):
            print(f"Table {j+1} on page {i+1}:")
            for row in table:
                print(row)

Advanced Table Extraction

import pandas as pd

with pdfplumber.open("document.pdf") as pdf:
    all_tables = []
    for page in pdf.pages:
        tables = page.extract_tables()
        for table in tables:
            if table:  # Check if table is not empty
                df = pd.DataFrame(table[1:], columns=table[0])
                all_tables.append(df)

# Combine all tables
if all_tables:
    combined_df = pd.concat(all_tables, ignore_index=True)
    combined_df.to_excel("extracted_tables.xlsx", index=False)

reportlab - Create PDFs

Basic PDF Creation

from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas

c = canvas.Canvas("hello.pdf", pagesize=letter)
width, height = letter

# Add text
c.drawString(100, height - 100, "Hello World!")
c.drawString(100, height - 120, "This is a PDF created with reportlab")

# Add a line
c.line(100, height - 140, 400, height - 140)

# Save
c.save()

Create PDF with Multiple Pages

from reportlab.lib.pagesizes import letter
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, PageBreak
from reportlab.lib.styles import getSampleStyleSheet

doc = SimpleDocTemplate("report.pdf", pagesize=letter)
styles = getSampleStyleSheet()
story = []

# Add content
title = Paragraph("Report Title", styles['Title'])
story.append(title)
story.append(Spacer(1, 12))

body = Paragraph("This is the body of the report. " * 20, styles['Normal'])
story.append(body)
story.append(PageBreak())

# Page 2
story.append(Paragraph("Page 2", styles['Heading1']))
story.append(Paragraph("Content for page 2", styles['Normal']))

# Build PDF
doc.build(story)

Subscripts and Superscripts

IMPORTANT: Never use Unicode subscript/superscript characters (₀₁₂₃₄₅₆₇₈₉, ⁰¹²³⁴⁵⁶⁷⁸⁹) in ReportLab PDFs. The built-in fonts do not include these glyphs, causing them to render as solid black boxes.

Instead, use ReportLab's XML markup tags in Paragraph objects:

from reportlab.platypus import Paragraph
from reportlab.lib.styles import getSampleStyleSheet

styles = getSampleStyleSheet()

# Subscripts: use <sub> tag
chemical = Paragraph("H<sub>2</sub>O", styles['Normal'])

# Superscripts: use <super> tag
squared = Paragraph("x<super>2</super> + y<super>2</super>", styles['Normal'])

For canvas-drawn text (not Paragraph objects), manually adjust font the size and position rather than using Unicode subscripts/superscripts.

Command-Line Tools

pdftotext (poppler-utils)

# Extract text
pdftotext input.pdf output.txt

# Extract text preserving layout
pdftotext -layout input.pdf output.txt

# Extract specific pages
pdftotext -f 1 -l 5 input.pdf output.txt  # Pages 1-5

qpdf

# Merge PDFs
qpdf --empty --pages file1.pdf file2.pdf -- merged.pdf

# Split pages
qpdf input.pdf --pages . 1-5 -- pages1-5.pdf
qpdf input.pdf --pages . 6-10 -- pages6-10.pdf

# Rotate pages
qpdf input.pdf output.pdf --rotate=+90:1  # Rotate page 1 by 90 degrees

# Remove password
qpdf --password=mypassword --decrypt encrypted.pdf decrypted.pdf

pdftk (if available)

# Merge
pdftk file1.pdf file2.pdf cat output merged.pdf

# Split
pdftk input.pdf burst

# Rotate
pdftk input.pdf rotate 1east output rotated.pdf

Common Tasks

Extract Text from Scanned PDFs

# Requires: pip install pytesseract pdf2image
import pytesseract
from pdf2image import convert_from_path

# Convert PDF to images
images = convert_from_path('scanned.pdf')

# OCR each page
text = ""
for i, image in enumerate(images):
    text += f"Page {i+1}:\n"
    text += pytesseract.image_to_string(image)
    text += "\n\n"

print(text)

Add Watermark

from pypdf import PdfReader, PdfWriter

# Create watermark (or load existing)
watermark = PdfReader("watermark.pdf").pages[0]

# Apply to all pages
reader = PdfReader("document.pdf")
writer = PdfWriter()

for page in reader.pages:
    page.merge_page(watermark)
    writer.add_page(page)

with open("watermarked.pdf", "wb") as output:
    writer.write(output)

Extract Images

# Using pdfimages (poppler-utils)
pdfimages -j input.pdf output_prefix

# This extracts all images as output_prefix-000.jpg, output_prefix-001.jpg, etc.

Password Protection

from pypdf import PdfReader, PdfWriter

reader = PdfReader("input.pdf")
writer = PdfWriter()

for page in reader.pages:
    writer.add_page(page)

# Add password
writer.encrypt("userpassword", "ownerpassword")

with open("encrypted.pdf", "wb") as output:
    writer.write(output)

Quick Reference

Task	Best Tool	Command/Code
Merge PDFs	pypdf	`writer.add_page(page)`
Split PDFs	pypdf	One page per file
Extract text	pdfplumber	`page.extract_text()`
Extract tables	pdfplumber	`page.extract_tables()`
Create PDFs	reportlab	Canvas or Platypus
Command line merge	qpdf	`qpdf --empty --pages ...`
OCR scanned PDFs	pytesseract	Convert to image first
Fill PDF forms	pdf-lib or pypdf (see FORMS.md)	See FORMS.md

Next Steps

For advanced pypdfium2 usage, see REFERENCE.md
For JavaScript libraries (pdf-lib), see REFERENCE.md
If you need to fill out a PDF form, follow the instructions in FORMS.md
For troubleshooting guides, see REFERENCE.md

pptx

name: pptx description: "Use this skill any time a .pptx or .potx file is involved in any way — as input, output, or both. This includes: creating slide decks, pitch decks, or presentations; reading, parsing, or extracting text from any .pptx or .potx file (even if the extracted content will be used elsewhere, like in an email or summary); editing, modifying, or updating existing presentations; combining or splitting slide files; working with templates (.potx), layouts, speaker notes, or comments. Trigger whenever the user mentions "deck," "slides," "presentation," or references a .pptx or .potx filename, regardless of what they plan to do with the content afterward. If a .pptx or .potx file needs to be opened, created, or touched, use this skill." license: Proprietary. LICENSE.txt has complete terms

PPTX creation, editing, and analysis

A .pptx is a ZIP archive of XML files. Choose your approach by task:

Task	Approach
Create a new deck	Write a `pptxgenjs` script — see gotchas below
Edit an existing deck, or build from a template	unzip → edit `ppt/slides/slideN.xml` → zip
Read content	`markitdown deck.pptx` (one block per slide under `<!-- Slide number: N -->` markers); visual grid: `python scripts/thumbnail.py deck.pptx`

Scripts

Paths are relative to this skill's directory. Everything else is plain Python, node, or shell.

Script	What it does
`scripts/thumbnail.py deck.pptx [prefix]`	Labeled grid of every slide, for picking template layouts. `.pptx` only. Pass `prefix` — it defaults to `thumbnails`, which overwrites the grids of any other deck done in the same directory
`scripts/add_slide.py unpacked/ slide2.xml [--after slideN.xml]`	Duplicate a slide (or a `slideLayoutN.xml`) with all the package bookkeeping. Also takes a `.pptx` directly with `-o out.pptx`
`scripts/clean.py unpacked/`	Delete slides, media, and rels no longer referenced. Run after `<p:sldIdLst>` is final
`scripts/office/validate.py deck.pptx [--original src.pptx]`	Schema, relationship, content-type, chart and slide checks; each failure names its fix. Pass `--original` for any template-derived deck — it baselines the schema checks against the template, so the template's own XSD errors don't read as yours
`scripts/office/soffice.py --headless --convert-to pdf deck.pptx`	LibreOffice wrapper — bare `soffice` hangs in this sandbox

Creating with pptxgenjs — gotchas

pptxgenjs is preinstalled — do not run npm install first; write the script and require('pptxgenjs') directly. Only if that require fails: npm install pptxgenjs. The model knows the API; these are the footguns:

Set pres.layout before adding slides. The default canvas is LAYOUT_16x9 = 10" × 5.625", not 13.3" wide. Coordinates past the edge are written, not clamped — the shape just isn't on the slide. (LAYOUT_WIDE is 13.3" × 7.5".)
Hex colors: never #, never 8 digits. color: "FF0000". Both "#FF0000" and alpha baked into the hex ("00000020") corrupt the file. For translucency: transparency: 0-100 on fills and images, opacity: 0.0-1.0 on shadows — each is silently ignored on the other.
pptxgenjs mutates option objects in place (converts values to EMU on first use). Never share one shadow/options object across two add* calls — build a fresh object each time.
Shadow offset must be ≥ 0 — a negative offset corrupts the file. To cast a shadow upward, use angle: 270 with a positive offset.
letterSpacing is silently ignored — the real option is charSpacing.
Lists: bullet: true on each item, never a literal • (renders double bullets). Set breakLine: true on every array item except the last. Space bulleted paragraphs with paraSpaceAfter, not lineSpacing (huge gaps).
One new pptxgen() per output file — never reuse an instance.
rectRadius only works on ROUNDED_RECTANGLE, not RECTANGLE.
Gradient fills aren't supported — use a gradient image as the background instead.
Text boxes have built-in internal padding — set margin: 0 whenever text must align with a shape, line, or icon at the same x.
Speaker notes go in slide.addNotes("...") (plain text, once per slide), never in a text box on the slide.
Keep charts native. Use addChart() for everything PowerPoint can chart (pass an array of {type, data, options} for combos). For PowerPoint-native features the library doesn't expose (trendlines, error bars), compute the extra series yourself or post-process the generated OOXML — do not fall back to a rendered image. Only chart types PowerPoint has no native form for (Sankey, network, chord) go in as images.
Default charts render bare — no title, no data labels, dated palette. Set showTitle + title, showValue: true + dataLabelPosition, chartColors: [...] from your palette, and quiet the frame (catAxisLabelColor/valAxisLabelColor, valGridLine: { color, size }, catGridLine: { style: "none" }, showLegend: false for a single series).
On a stacked bar or column chart, dataLabelPosition must be ctr, inEnd, or inBase. outEnd corrupts the file.
A combo series using secondaryValAxis/secondaryCatAxis needs both valAxes and catAxes on the chart options, two entries each. Without them pptxgenjs writes axis ids it never declares, and PowerPoint discards that chart and reports the file as corrupt. Supplying only valAxes is not enough.
After writeFile(), run python scripts/office/validate.py deck.pptx. It reports the two chart faults above and the slide-XML defects PowerPoint refuses, and names the fix for each. Fix them in your generator, not by hand-editing the packed XML.
Never reorder the children of <p:presentation>. pptxgenjs writes <p:notesMasterIdLst> right after <p:sldIdLst> and points both masters at one theme part. PowerPoint reads that happily — move the element and the same deck becomes unopenable.
Icons: render react-icons to SVG (ReactDOMServer.renderToStaticMarkup), rasterize with sharp at ≥256px, and insert via addImage({ data: "image/png;base64," + buf.toString("base64") }) — the image/png;base64, prefix is required (react-icons, react, react-dom, and sharp are preinstalled — npm install react-icons react react-dom sharp only if a require fails).

Editing existing decks and templates

Pick layouts first: python scripts/thumbnail.py template.pptx template-thumbs writes a labeled grid of every slide and prints the file(s) it created — template-thumbs.jpg, split into template-thumbs-N.jpg past 12 slides. Always pass that second argument, named after the deck. It defaults to thumbnails, so two decks thumbnailed in one directory silently overwrite each other's grids — the first deck's are simply gone (template analysis only — visual QA needs the full-resolution renders from Converting to Images; it only accepts .pptx, so copy a .potx to a .pptx name first). Use it with markitdown to map each content section onto a template slide, and vary the layouts — don't put every section on the same title-and-bullets slide.

python3 -c "import sys,zipfile; zipfile.ZipFile(sys.argv[1]).extractall('unpacked')" deck.pptx
python scripts/add_slide.py unpacked/ slide2.xml --after slide2.xml   # duplicate a slide (or slideLayoutN.xml); prints the new slide's path
# reorder / delete slides = edit <p:sldIdLst> in ppt/presentation.xml
python scripts/clean.py unpacked/                                     # after deletions: removes orphaned slides, media, rels
# edit slide content in ppt/slides/slideN.xml
(cd unpacked && rm -f ../out.pptx && zip -Xr ../out.pptx .)           # zip from INSIDE the dir; rm first or deleted parts survive
python scripts/office/validate.py out.pptx --original deck.pptx

Do all structural work — add, delete, reorder — before editing any slide's content. add_slide.py copies a slide file verbatim, so duplicating after you edit clones the edited content; and clean.py deletes any slide missing from <p:sldIdLst>, including one you just wrote.
Never copy a slide file by hand — add_slide.py does every registration a new slide needs and reports what it made (Created ppt/slides/slide17.xml from slide2.xml). It also works directly on a file: add_slide.py deck.pptx slide2.xml -o out.pptx — pass -o, or it rewrites the input deck in place. A duplicated slide still references its source's chart/SmartArt/embedded-object parts rather than cloning them, so editing one slide's chart changes the other's.
If you use python-pptx, three things it won't do: duplicate a slide (its only entry point is add_slide(layout)), preserve formatting through text_frame.text = "..." (that collapses the paragraph to a single unstyled run — assign run.text instead), or read the SVG/EMF most template art uses (add_picture raises UnidentifiedImageError).
Legacy .ppt must be converted first: python scripts/office/soffice.py --headless --convert-to pptx file.ppt. .potx templates unpack and pack identically — keep the .potx extension on the output.
To reuse a template icon or image, duplicate a slide or layout that already contains it.

When filling in a template:

If you script an XML transform, parse with defusedxml.minidom — round-tripping OOXML through xml.etree.ElementTree rewrites namespace prefixes and corrupts the deck.
Template slots ≠ source items. If the template shows 4 team members and you have 3, delete the 4th member's entire group (image + text boxes), not just its text — then check for orphaned visuals in QA.
One <a:p> per list item — never concatenate items into a single paragraph. Copy the sibling <a:pPr> to preserve spacing, and put b="1" on the <a:rPr> of titles, section headers, and inline labels (Status:, Owner:).
Let bullets inherit from the layout; only add <a:buChar>, <a:buAutoNum> (numbered), or <a:buNone> to override — never a literal • in the text.
Text with leading or trailing spaces needs xml:space="preserve" on its <a:t>.

Design Ideas

Don't create boring slides. Plain bullets on a white background won't impress anyone. Consider ideas from this list for each slide.

Before Starting

Pick a bold, content-informed color palette: The palette should feel designed for THIS topic. If swapping your colors into a completely different presentation would still "work," you haven't made specific enough choices.
Dominance over equality: One color should dominate (60-70% visual weight), with 1-2 supporting tones and one sharp accent. Never give all colors equal weight.
Dark/light contrast: Dark backgrounds for title + conclusion slides, light for content ("sandwich" structure). Or commit to dark throughout for a premium feel.
Commit to a visual motif: Pick ONE distinctive element and repeat it — rounded image frames, icons in colored circles. Carry it across every slide. Do not use a color bar or accent stripe as your motif (see Avoid list).

Color Palettes

Choose colors that match your topic — don't default to generic blue. Use these palettes as inspiration:

Theme	Primary	Secondary	Accent
Midnight Executive	`1E2761` (navy)	`CADCFC` (ice blue)	`FFFFFF` (white)
Forest & Moss	`2C5F2D` (forest)	`97BC62` (moss)	`F5F5F5` (cream)
Coral Energy	`F96167` (coral)	`F9E795` (gold)	`2F3C7E` (navy)
Warm Terracotta	`B85042` (terracotta)	`E7E8D1` (sand)	`A7BEAE` (sage)
Ocean Gradient	`065A82` (deep blue)	`1C7293` (teal)	`21295C` (midnight)
Charcoal Minimal	`36454F` (charcoal)	`F2F2F2` (off-white)	`212121` (black)
Teal Trust	`028090` (teal)	`00A896` (seafoam)	`02C39A` (mint)
Berry & Cream	`6D2E46` (berry)	`A26769` (dusty rose)	`ECE2D0` (cream)
Sage Calm	`84B59F` (sage)	`69A297` (eucalyptus)	`50808E` (slate)
Cherry Bold	`990011` (cherry)	`FCF6F5` (off-white)	`2F3C7E` (navy)

For Each Slide

Every slide needs a visual element — image, chart, icon, or shape. Text-only slides are forgettable.

Layout options:

Two-column (text left, illustration on right)
Icon + text rows (icon in colored circle, bold header, description below)
2x2 or 2x3 grid (image on one side, grid of content blocks on other)
Half-bleed image (full left or right side) with content overlay

Data display:

Large stat callouts (big numbers 60-72pt with small labels below)
Comparison columns (before/after, pros/cons, side-by-side options)
Timeline or process flow (numbered steps, arrows)

Visual polish:

Icons in small colored circles next to section headers
Italic accent text for key stats or taglines

Typography

Font names you write into the .pptx are rendered by the user's PowerPoint, not by this environment. Your visual QA renders via LibreOffice, which substitutes fonts it doesn't have — and for some fonts the substitute has different widths, so your QA preview can show text overflow (or fit) that the real deck won't have. To keep your QA trustworthy:

Safe fonts (render true-to-width in QA and ship with Office): Arial, Calibri, Cambria, Times New Roman, Courier New, Bookman Old Style, Century Schoolbook. Use these for body text and anything where fit matters.
Headers with personality at zero QA risk: pair a safe-list serif header (Cambria, Bookman Old Style, Century Schoolbook) with a safe-list sans body (Calibri or Arial). You get visual contrast without giving up reliable overflow checks.
If the user asks for a font outside the safe list (e.g. Georgia or Trebuchet MS): use it where the user asked, but size those containers with extra slack (~10%) and don't trust QA text-fit on those elements — the preview of that font is approximate. If the user hasn't specified, prefer safe-list fonts for body text.
QA-unreliable fonts (substitute has different widths — overflow checks can be wrong): Georgia, Trebuchet MS, Impact, Arial Black, Garamond, Consolas, Palatino Linotype. Calibri Light substitution varies by environment; treat as QA-unreliable. Fine for titles/accents with slack; don't trust QA text-fit on these.
Never default to Aptos — Office's post-2023 default has no metric-compatible substitute here and is missing from older Office installs, so it's unreliable on both ends.

Element	Size
Slide title	36-44pt bold
Section header	20-24pt bold
Body text	14-16pt
Captions	10-12pt muted

Spacing

0.5" minimum margins
0.3-0.5" between content blocks
Leave breathing room—don't fill every inch

Avoid (Common Mistakes)

Don't repeat the same layout — vary columns, cards, and callouts across slides
Don't center body text — left-align paragraphs and lists; center only titles
Don't skimp on size contrast — titles need 36pt+ to stand out from 14-16pt body
Don't default to blue — pick colors that reflect the specific topic
Don't mix spacing randomly — choose 0.3" or 0.5" gaps and use consistently
Don't style one slide and leave the rest plain — commit fully or keep it simple throughout
Don't create text-only slides — add images, icons, charts, or visual elements; avoid plain title + bullets
Don't forget text box padding — when aligning lines or shapes with text edges, set margin: 0 on the text box or offset the shape to account for padding
Don't use low-contrast elements — icons AND text need strong contrast against the background; avoid light text on light backgrounds or dark text on dark backgrounds
NEVER use accent lines under titles — these are a hallmark of AI-generated slides; use whitespace or background color instead
NEVER add decorative color bars or accent stripes — this includes: header/footer bars spanning the slide width, vertical sidebar stripes down one edge of the slide, thin accent stripes along one edge of a card or content block, and "single-side borders" on rectangles. These read as AI-generated filler. If you want to set a card apart, use a subtle background tint, a drop shadow, or an icon — not an edge stripe.
Don't default to cream/beige backgrounds — when no background is specified, use white (FFFFFF) or the user's brand palette; avoid warm-neutral defaults like F5F5DC, FAF0E6, FAEBD7, FFF8E1
Don't ship text that overflows its shape — if text doesn't fit, reduce font size, split across slides, or enlarge the container; never leave content cut off or spilling past bounds

QA (Required)

Your first render usually has a few real issues — overlaps, overflow, misalignment. Find and fix those, re-render only the slides you changed, and stop.

Content QA

markitdown output.pptx

Check for missing content, typos, wrong order.

When using templates, check for leftover placeholder text:

markitdown output.pptx | grep -iE "\bx{3,}\b|lorem|ipsum|\bTODO|\[insert|this.*(page|slide).*layout"

If grep returns results, fix them before declaring success.

File QA (required)

python scripts/office/validate.py output.pptx                      # built from scratch
python scripts/office/validate.py output.pptx --original src.pptx  # built from a template

If the deck came from a template, always pass --original. A template may itself contain parts the XSD rejects, so a bare run can report failures you never caused — and a genuine regression can hide among them. --original baselines the schema and slide checks against the template, suppressing errors it already had. The structural checks — relationships, content types, charts — ignore --original and report template-inherited problems either way, so read those on their own merits.

pptxgenjs emits chart XML PowerPoint refuses to open, and every other tool accepts: python-pptx opens those decks, LibreOffice renders them, the XSD passes them. Every failure names its fix. Fix it in the generator and rebuild.

Visual QA

Convert the slides to images (see Converting to Images) and inspect every one. After staring at the generating code you tend to see what you expect rather than what rendered, so look at the images fresh (a subagent works well for this if you have one). User-visible defects to look for:

Text overflow or text cut off at a box or slide boundary — check this first. It is the most common defect and always user-visible. (For a font the previewer renders unreliably per Typography, the preview is approximate: trust the ~10% slack you left, not its apparent fit.)
Overlapping elements (text through shapes, lines through words, stacked elements)
Source citations or footers colliding with content above
Elements too close (< 0.3" gaps) or cards/sections nearly touching
Uneven gaps (large empty area in one place, cramped in another)
Insufficient margin from slide edges (< 0.5")
Columns or similar elements not aligned consistently
Low-contrast text (e.g., light gray text on cream-colored background)
Template decoration mispositioned after text replacement — e.g., a title underline positioned for one line, but the replaced title wrapped to two
Low-contrast icons (e.g., dark icons on dark backgrounds without a contrasting circle)
Text boxes too narrow causing excessive wrapping
Leftover placeholder content

Converting to Images

Convert presentations to individual slide images for visual inspection:

python scripts/office/soffice.py --headless --convert-to pdf output.pptx
rm -f slide-*.jpg
pdftoppm -jpeg -r 150 output.pdf slide
ls -1 "$PWD"/slide-*.jpg

Pass the absolute paths printed above directly to the view tool. The rm clears stale images from prior runs. pdftoppm zero-pads based on page count: slide-1.jpg for decks under 10 pages, slide-01.jpg for 10-99, slide-001.jpg for 100+.

After fixes, rerun all four commands above — the PDF must be regenerated from the edited .pptx before pdftoppm can reflect your changes.

Dependencies

pptxgenjs (npm, preinstalled — install only if require('pptxgenjs') fails) · markitdown[pptx], Pillow, defusedxml, lxml (pip — text dump, thumbnail, clean, validate) · LibreOffice (soffice, auto-configured for sandboxed environments via scripts/office/soffice.py) · pdftoppm (Poppler)

xlsx

name: xlsx description: "Use this skill any time a spreadsheet file is the primary input or output. This means any task where the user wants to: open, read, edit, or fix an existing .xlsx, .xlsm, .xltx, .csv, or .tsv file (e.g., adding columns, computing formulas, formatting, charting, cleaning messy data); create a new spreadsheet from scratch or from other data sources; or convert between tabular file formats. Trigger especially when the user references a spreadsheet file by name or path — even casually (like "the xlsx in my downloads") — and wants something done to it or produced from it. Also trigger for cleaning or restructuring messy tabular data files (malformed rows, misplaced headers, junk data) into proper spreadsheets. The deliverable must be a spreadsheet file. Do NOT trigger when the primary deliverable is a Word document, HTML report, standalone Python script, database pipeline, or Google Sheets API integration, even if tabular data is involved." license: Proprietary. LICENSE.txt has complete terms

XLSX creation, editing, and analysis

Task	Approach
Create or edit with formulas/formatting	`openpyxl` — see gotchas below
Bulk data in or out	`pandas` (`read_excel`, `to_excel`)
Quick look at a sheet	`markitdown file.xlsx` — `## SheetName` per sheet; reads `.xlsm` too. No cell coordinates, so don't plan edits from it
Read a model (formulas and values)	two `load_workbook` passes — see gotchas

openpyxl, pandas, and markitdown are preinstalled — do not run pip install first; write the script and import directly. Only if an import fails (or the markitdown command is missing): pip install the missing package.

Script paths below are relative to this skill's directory.

Requirements for every output

Professional font (Arial, Times New Roman) throughout, unless the user says otherwise.
Zero formula errors. Never ship while recalc.py reports errors_found. If you think an error predates you, prove it: load the original with data_only=True and look at that cell. An error you introduced looks exactly like one you inherited.
Use formulas, never hardcoded results. Write sheet['B10'] = '=SUM(B2:B9)', not the Python-computed total. The sheet must recalculate when its inputs change.
Follow the user's spec literally. Exact tab names, exact column headers, and the formula they spelled out. A redesign that computes something else fails, however elegant.
Document every assumption and hardcoded number where the reader will see it — a cell comment, or an adjacent cell at a table's end. Cite a real source when one exists (Source: Company 10-K, FY2024, Page 45, Revenue Note, [SEC EDGAR URL]); when the number came from the user, say so plainly.
A workbook you create for someone to fill in needs a short legend naming which cells to edit, and one example row of realistic values showing the expected format. Never add such a row to a file you were asked to edit.
Editing an existing file: match its conventions exactly. They override every guideline here. Find its designated input cells first — a distinct font color, fill, or shading marks them — write only there, and leave every existing formula untouched.

Recalculate (mandatory whenever the file contains formulas)

openpyxl writes formulas as strings with no cached values. Until you recalculate, every formula cell reads back as None to anything reading cached values — pandas, load_workbook(data_only=True), and most previewers.

python scripts/recalc.py output.xlsx [timeout_seconds]   # default 30

LibreOffice computes every formula, the file is rewritten in place, and you get JSON: status (success | errors_found), total_formulas, total_errors, and an error_summary naming up to 100 cells per error type (locations_truncated says how many it withheld — trust total_errors, not the length of the list). Fix what it names and run it again. JSON with an error key instead of a status means nothing was recalculated, and only that case exits non-zero — errors_found exits 0, so never treat a clean exit as a clean workbook.

A green recalc proves your formulas evaluate, not that they are right. An off-by-one range or a reference to the wrong row yields a clean, error-free file with wrong numbers. Write 2–3 formulas first and check they pull the values you expect, before building out a grid.

A workbook that links to another file loses those links if you re-save it with openpyxl and then recalculate. Such a formula reads ='[1]Returns Analysis'!$B$2 — the [1] is an index into the workbook's external-reference list, naming a separate file on disk, not a sheet. That file is rarely present here, so the cell's cached value is the only thing holding its data. openpyxl strips that value on save; LibreOffice then has to resolve the reference for real, fails, writes #NAME?, and deletes every link. recalc.py refuses to run in that state — copy those cells' values out of the original before you save over them (--force overrides, and accepts the loss).

Choosing formulas that survive verification

LibreOffice implements fewer functions than Excel, and one it cannot evaluate becomes a literal #NAME? baked into the file you deliver.

Prefer Excel-2007-era functions — SUMIFS, INDEX, MATCH, IFERROR, SUMPRODUCT — which need no prefix.
Six post-2007 functions work, but only with an _xlfn. prefix, because openpyxl writes your formula into the XML verbatim and Excel stores post-2007 names prefixed (its UI hides the prefix): _xlfn.TEXTJOIN, _xlfn.CONCAT, _xlfn.IFS, _xlfn.SWITCH, _xlfn.MAXIFS, _xlfn.MINIFS. Written bare, each yields #NAME?.
Never use XLOOKUP, XMATCH, SORT, FILTER, UNIQUE, or SEQUENCE. The runtime's LibreOffice cannot evaluate them under any prefix. Newer builds do evaluate them, but they are spilling array functions and an openpyxl-written file has no spill metadata, so only the top-left cell of the range gets a value — and recalc.py reports total_errors: 0 on the truncated result. Use INDEX/MATCH for lookups, and sort, filter, and de-duplicate in Python before writing the cells.
A formula LibreOffice could not parse is written back lowercased — a quick tell beside a #NAME?.

openpyxl gotchas

Reading a model takes two loads. data_only=True yields cached values with the formulas gone; the default yields formula strings with no values. One pass cannot give you both.
data_only=True is destructive if you save. That workbook has no formulas left, so saving replaces every one with a literal — permanently.
data_only=True on a file openpyxl just wrote returns None everywhere — run recalc.py first. (A formula whose result is "" also reads back as None.)
Merged cells: write the top-left anchor only. Every other cell in the range is a MergedCell whose .value is read-only.
.xlsm loses its macros unless you pass keep_vba=True to load_workbook.
A sheet name containing a space must be quoted in a cross-sheet reference: ='Assumptions Inputs'!$B$5. Unquoted, it evaluates to #VALUE!.

Financial models

Unless the user says otherwise, or the existing file already does something else.

Color: blue text (0,0,255) for hardcoded inputs and scenario levers · black for formulas · green (0,128,0) for links to another sheet · red (255,0,0) for links to another file · yellow fill (255,255,0) for key assumptions and cells the user should fill in.

Numbers: currency $#,##0, with the unit named in the header (Revenue ($mm)) · zeros render as -, including in percentages ($#,##0;($#,##0);-) · negatives in parentheses · percentages 0.0%, stored as fractions (0.15 renders 15.0%; storing 15 renders 1500.0%) · valuation multiples 0.0x · years as text ("2024", never 2,024).

Structure: every assumption in its own labeled cell, referenced by the formulas that use it (=B5*(1+$B$6), never =B5*1.05) · formulas consistent across every projection period, since a lone edited cell mid-row is the commonest silent error · guard denominators that can be zero.

Dependencies

openpyxl, pandas, markitdown (pip, preinstalled — install only if an import fails or the command is missing) · LibreOffice (soffice, auto-configured for sandboxed environments via scripts/office/soffice.py)

Skills

Skill Details

Skills

About This Repository

Disclaimer

Skill Sets

Try in Claude Code, Claude.ai, and the API

Claude Code

Claude.ai

Claude API

Creating a Basic Skill

Partner Skills

docx

DOCX creation, editing, and analysis

Creating with docx-js — gotchas

Verify the output

Editing existing documents

Comments

Dependencies

pdf

PDF Processing Guide

Overview

Quick Start

Python Libraries

pypdf - Basic Operations

Merge PDFs

Split PDF

Extract Metadata

Rotate Pages

pdfplumber - Text and Table Extraction

Extract Text with Layout

Extract Tables

Advanced Table Extraction

reportlab - Create PDFs

Basic PDF Creation

Create PDF with Multiple Pages

Subscripts and Superscripts

Command-Line Tools

pdftotext (poppler-utils)

qpdf

pdftk (if available)

Common Tasks

Extract Text from Scanned PDFs

Add Watermark

Extract Images

Password Protection

Quick Reference

Next Steps

pptx

PPTX creation, editing, and analysis

Scripts

Creating with pptxgenjs — gotchas

Editing existing decks and templates

Design Ideas

Before Starting

Color Palettes

For Each Slide

Typography

Spacing

Avoid (Common Mistakes)

QA (Required)

Content QA

File QA (required)

Visual QA

Converting to Images

Dependencies

xlsx

XLSX creation, editing, and analysis

Requirements for every output

Recalculate (mandatory whenever the file contains formulas)

Choosing formulas that survive verification

openpyxl gotchas

Financial models

Dependencies

template-skill

name: template-skill description: Replace with description of the skill and when Claude should use it.

Insert instructions below

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