# PPTX > Create polished, editable PowerPoint files for slide decks, presentations, and explicit .pptx requests. - Skill: `modsetter/pptx` (Agent Skill) - Install (CLI): `npx skillmds@latest add modsetter/pptx` - Raw SKILL.md: https://api.skillmd.com/api/skills/modsetter/pptx/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: DevOps & Infra - Author: MODSetter (https://skillmd.com/u/modsetter) - Updated: 2026-09-21 - Page: https://skillmd.com/skills/modsetter/pptx --- # PPTX Create an editable `.pptx` in `/workspace` with the preinstalled `python-pptx` package. Never install or download dependencies. For a new deck, set `output_path` to a descriptive `/workspace/.pptx` path. Use this order: 1. Plan the slide purposes and visual system. 2. Build the complete deck. 3. Run the local checks below. 4. Verify the complete deck once. 5. If verification fails, repair it once and reverify. 6. Save the artifact only after the latest verification passes. ## Authoring rules - Use a 16:9 presentation unless the user requests another aspect ratio. Set `prs.slide_width` and `prs.slide_height` once; slide size is deck-wide. - Use a consistent layout, palette, type scale, spacing system, and placement grid across the deck. - Prefer a suitable built-in PowerPoint layout and its native placeholders over unrelated free-positioned text boxes. A native placeholder is a layout container, not permission to leave filler copy visible: populate every visible placeholder with final content unless the user explicitly requests a reusable template. - Treat requests for "image placeholders", "visual suggestions", or "design concepts" as design direction for a finished deck. Add the real visual or a finished graphic treatment; do not display those instructions as slide text. - Keep at least 0.5 inches of outer margin and 0.3 inches between unrelated content regions. Define title, subtitle, body, and footer regions once and reuse them; title and subtitle regions must not overlap. - Give every slide one clear purpose. Keep body copy concise: normally no more than six bullets, with short phrases rather than paragraphs. - Set fonts in the deck by family name. Default to Arial for fit-sensitive text; LibreOffice substitutes the metric-compatible Liberation Sans installed in the sandbox. Use Times New Roman/Liberation Serif when a serif is appropriate, and Noto for scripts they do not cover. If the user requires another font, leave about 10% extra width and height because LibreOffice and PowerPoint may use different metrics. - Never guess or hardcode a font-file path. A path is needed only when calling `text_frame.fit_text(...)`; resolve it at runtime with `fc-match`, for example `fc-match -f '%{file}\n' Arial`, and use the first non-empty line. If no file is returned, do not call `fit_text`; shorten the text or enlarge its region. - Use 32–40 pt titles, 18–24 pt subtitles, and body text of at least 18 pt. Set `text_frame.word_wrap = True` and explicit text-frame margins; use zero margins where text must align exactly with a nearby shape. - Do not use PowerPoint runtime autofit (`text_frame.auto_size`) because PowerPoint and LibreOffice can resolve it differently. For a single-style title or subtitle, `text_frame.fit_text(...)` may be used with the font file resolved above so the fitted size is written into the PPTX. If a title must shrink below 28 pt or a subtitle below 16 pt, shorten it, enlarge its region, or split the content across slides instead. - Keep every shape on the slide canvas. Intentional edge bleed may cross a slide boundary, but do not park unused shapes off-canvas or hide backup slides. - Preserve image aspect ratios. When calling `add_picture`, derive the missing dimension from the source image instead of setting both width and height to unrelated values. Extended crop values are legal, but the left and right crop fractions must sum to less than 1, as must the top and bottom fractions, so some of the image remains visible. - Prefer editable native text, shapes, tables, and charts. Avoid SmartArt and elaborate gradients whose LibreOffice conversion is unreliable. ## Local validation Before verification, run local assertions against the complete deck. Every failure must name the slide and shape so it can be repaired directly: - required slide count and content are present; - title and subtitle regions do not overlap; - area shapes have positive width and height, while a connector may have one zero extent but not two; - every shape intersects the slide canvas; and - fitted title and subtitle text remains above the minimum sizes above; - no visible TODOs, editor notes, design suggestions, or replacement placeholders remain in a finished deck. Save the PPTX to `output_path`, reopen it with `python-pptx`, and confirm the slide count and required content. Do not call `verify_artifact` after each slide; verification renders and reviews the whole deck. ## Revisions Start an in-place revision with `load_artifact_for_revision`. Open `primary_path` with `python-pptx`, edit that current deck directly, and save the result to `expected_output_path`; for the revision, that path is `output_path`. Preserve unaffected slide masters, layouts, notes, relationships, and media. Use `markdown_path` as textual context, not as a replacement deck. Do not reconstruct slides with vision; `verify_artifact` may use vision after the revision is written. A changed title, filename, or design is still the same artifact unless the user explicitly asks for a separate copy. After verification, save the revision with the returned `artifact_id` and `expected_generation`. ## Verify and save 1. Call `verify_artifact(path=output_path, format="pptx")` once after local validation. 2. If it returns blocking findings, fix all of them together. Repair the exact offending shapes in place: update, resize, or delete obsolete elements before adding replacements. Never cover an old element with a new one. 3. Rerun the local checks, overwrite the same `output_path`, and call `verify_artifact` once more. Warnings are advisory. 4. If any blocker remains, stop and explain it. Do not enter another automatic rewrite loop. Call `save_artifact` only when the latest verification of those exact PPTX bytes returned `status="verified"`, using `save_artifact(path=output_path, title="...", markdown_representation="...")`. A failed verification invalidates every earlier pass: never attempt to save afterward. Working files may use any paths; no source file, preview file, or matching filename stem is part of the publication contract. The Markdown representation must faithfully contain the deck's substantive text for accessibility and search.