| name | pptx |
| description | Use this skill whenever the user wants to read, create, or edit PowerPoint presentations (.pptx files). Includes content extraction, creating slides from scratch, editing templates, adding charts/tables/images, and visual QA. |
PPTX Processing
Strategy by Task
| Task | Approach |
|---|
| Read / analyze content | uv run --with "markitdown[pptx]" |
| Edit existing template | Unpack XML → edit → repack |
| Create from scratch | pptxgenjs npm package |
| Visual inspection | Convert to images via LibreOffice + pdftoppm |
Reading Content
uv run --with "markitdown[pptx]" -m markitdown presentation.pptx
uv run --with "markitdown[pptx]" -m markitdown output.pptx | grep -iE "xxxx|lorem|ipsum"
mkdir unpacked && cp presentation.pptx unpacked/prs.zip
cd unpacked && unzip prs.zip -d contents
Creating from Scratch (pptxgenjs)
Use when there is no template to start from.
npm install -g pptxgenjs
const pptxgen = require("pptxgenjs");
const prs = new pptxgen();
let slide = prs.addSlide();
slide.addText("Title Text", { x: 0.5, y: 0.5, w: 9, h: 1, fontSize: 44, bold: true, color: "1E2761" });
slide.addText("Body content.", { x: 0.5, y: 2, w: 9, h: 4, fontSize: 16 });
slide.addImage({ path: "photo.jpg", x: 5, y: 1.5, w: 4, h: 3 });
slide.addTable(
[["Col A", "Col B"], ["Row 1", "Data"]],
{ x: 0.5, y: 1.5, w: 4, colW: [2, 2], border: { pt: 1, color: "CFCFCF" } }
);
prs.writeFile({ fileName: "output.pptx" });
Editing Existing Presentations (XML)
mkdir unpacked && cp input.pptx unpacked/prs.zip
cd unpacked && unzip prs.zip -d contents
cd contents && zip -r ../../output.pptx .
uv run --with lxml - <<'EOF'
from lxml import etree
tree = etree.parse("contents/ppt/slides/slide1.xml")
tree.write("contents/ppt/slides/slide1.xml", xml_declaration=True, encoding="UTF-8")
EOF
Design Principles
Don't create boring slides. Plain bullets on white are forgettable. Pick a deliberate palette and stick to it.
Color Strategy
- One color dominates (60–70% visual weight), 1–2 supporting tones, one sharp accent
- Dark backgrounds for title and conclusion slides, light for content
- Pick colors matched to the topic — not default blue
| Theme | Primary | Secondary | Accent |
|---|
| Midnight Executive | 1E2761 | CADCFC | FFFFFF |
| Forest & Moss | 2C5F2D | 97BC62 | F5F5F5 |
| Coral Energy | F96167 | F9E795 | 2F3C7E |
| Charcoal Minimal | 36454F | F2F2F2 | 212121 |
Typography
- Slide title: 36–44pt bold
- Body: 14–16pt
- Avoid Arial for everything — pair a header font with a clean body font (e.g., Georgia + Calibri)
Layout Ideas (every slide needs a visual element)
- Two-column: text left, image/chart right
- Icon rows: colored-circle icon + bold header + description
- Large stat callout: 60–72pt number with small label below
- Half-bleed image with content overlay
Avoid
- Repeating the same layout across slides
- Centering body text (center titles only)
- Accent lines under titles (hallmark of AI-generated slides — use whitespace instead)
- Text-only slides
- Low-contrast text or icons
Visual QA (Required)
Assume there are problems. Convert slides to images and inspect.
soffice --headless --convert-to pdf output.pptx
pdftoppm -jpeg -r 150 output.pdf slide
pdftoppm -jpeg -r 150 -f 2 -l 2 output.pdf slide-fixed
Arch packages: sudo pacman -S libreoffice-fresh poppler
Use a subagent to inspect the images with fresh eyes — prompt it to look for: overlapping elements, text overflow, elements too close to edges, uneven gaps, low-contrast text, leftover placeholders.
QA Loop
- Generate → convert to images → inspect
- List every issue found (if none found, look again)
- Fix issues → re-verify affected slides
- Repeat until a full pass is clean
Quick Reference
| Task | uv invocation |
|---|
| Read text | uv run --with "markitdown[pptx]" -m markitdown |
| XML manipulation | uv run --with lxml |
| Thumbnail generation | uv run --with Pillow |
