pptx

The saved excerpt is a snapshot from when this skill was listed. The external source remains the complete and most current version.

---
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 `RECTANGL