PPTX Generator

PowerPoint Generator

Overview

Build real .pptx files with exec + Python python-pptx, which Navin ships. Do not run import checks or install anything up front: write the script, and only if it actually fails on a missing dependency, report it and ask before touching the environment. Story and slide plan come from presentation-designer; this skill executes.

The deck must always be editable. Every title, bullet, figure and label is a real text box, every picture a real picture. A slide pasted as a full-bleed screenshot is a rejected deliverable: the user cannot fix a typo, translate a label or reuse a chart.

Motion and 3D (mandatory)

Slides are not a web runtime. Motion on a slide is the theme tokens in design-system.json (motion.duration, motion.easing) and the engine classes .nv-anim-fade, .nv-anim-rise, .nv-anim-stagger, .nv-anim-scale. html2pptx freezes a frame. Three.js, framer-motion, GSAP, Lottie or a canvas FX on a slide become a screenshot. Reject that.

• Theme pack: photos/background.jpg, photos/left.jpg, photos/right.jpg are already in the selected theme. ppt_design deck places them. User attachments (logo, icons, screenshots) replace that slot. Do not ignore the pack and ship empty covers.
• Product UI: visual.kind: screenshot or layout: product-hero (browser chrome). Not a 3D canvas.
• A 3D product the user asked to spin: companion web page (three / R3F) or product-visuals video. Keep the PPTX as photos + editable type.
• Preview motion lives in slides/index.html (CSS only). Do not add a JS 3D engine there.

Language and locale gate (mandatory)

• Before creating or exporting a PPTX, require the user to explicitly select the presentation language. Never infer it from the prompt, UI language, template, names, or location. If absent, ask and stop generation.
• A deck is a simple deliverable. Do not file a board plan and wait for Build. Produce the PPTX in this turn. If a Document Template Attachment is present, that theme is locked. Materialize with its name. Do not ask magazine / swiss / corporate and do not change theme.
• If nothing is attached and presentation-designer has not locked a style (magazine / swiss / corporate), call ask_user and stop. Do not pick a freestyle palette.
• Preserve that language in every title, label, chart, legend, note and file metadata. Translate all source-template text, including small labels and example data.
• Apply locale-appropriate dates, decimal/grouping separators and currencies consistently, including native chart data labels.
• For Arabic and other RTL languages, set RTL/bidi paragraphs and right alignment, mirror layouts where appropriate while retaining logical reading order, and use fonts with complete glyph coverage (for example Noto Naskh Arabic, Noto Sans Arabic or Amiri). Verify shaping in the exported preview and avoid silent font fallback.

Typography & icon rules (mandatory)

• Never use em or en dashes (U+2014 / U+2013) in slide text. Use commas, colons, periods or parentheses instead.
• Never use emoji or generic AI-style icons on slides. Use numbers (01, 02), plain monochrome glyphs (✓ ✗ + −) or simple shapes consistent with the deck design.

Visual fidelity (mandatory)

• A Document Template Attachment is the visual source of truth. Keep its CSS, fonts, spacing, colors and slide layouts. Replace text, data and images only. Add photos when you have them. Theme motion tokens are the only animation on the PPTX. If the user asked for Three.js, ship a companion HTML page. Do not restyle the deck. Still run today's pipeline on that theme: ppt_design deck (outline, stagecraft, rhythm, preview, notes, critique), then ppt_qa.py, then html2pptx, then stamp notes. Do not skip QA because a pretty template is attached. The engine accepts features, columns, steps, phases, description. Prefer items + body.
• Tokens in design-system.json / theme.css are the only legal colors. Components in _engine/navin-ppt.css inherit them.
• Do not invent a freestyle deck (Inter + blue/purple gradients, glassmorphism, glow, generic startup dark mode). That look is a rejected deliverable.
• If no template is attached: pick a recommended pitch template from the workspace library (textbook, black_and_white_clean, startup, premium_black) via document-templates, materialize it, then fill it. Do not hand-author a new design system.
• Never restyle the template to "make it nicer". Adapt content length to the existing blocks; if a block does not fit, choose another slide layout from the same template or delete the block and rebalance.

Copy quality before conversion (mandatory)

• Titles are assertions, not labels ("Les équipes perdent 6 h/semaine", not "Problème").
• ≤6 bullets per slide, ≤12 words each. Cut filler and repeated claims.
• Every invented number stays consistent across slides and has a unit/timeframe.
• Scan for leftover sample copy, source-language strings, empty cards, and template captions that are instructions to the agent.

Core recipes

from pptx import Presentation
from pptx.util import Inches, Pt
from pptx.dml.color import RGBColor
from pptx.chart.data import CategoryChartData
from pptx.enum.chart import XL_CHART_TYPE

prs = Presentation("brand-template.pptx")   # inherit masters; or Presentation() for blank (13.33x7.5")

# Title + content slide via layout placeholders
slide = prs.slides.add_slide(prs.slide_layouts[1])
slide.shapes.title.text = "Titre du slide"
body = slide.placeholders[1].text_frame
body.text = "Point 1"
p = body.add_paragraph(); p.text = "Sous-point"; p.level = 1

# Free textbox
tb = slide.shapes.add_textbox(Inches(0.5), Inches(1.5), Inches(9), Inches(1))
run = tb.text_frame.paragraphs[0].add_run(); run.text = "42%"
run.font.size = Pt(54); run.font.bold = True; run.font.color.rgb = RGBColor(0x03,0x69,0xFF)

# Image, table, native chart
slide.shapes.add_picture("chart.png", Inches(1), Inches(2), width=Inches(6))
shape = slide.shapes.add_table(3, 4, Inches(0.5), Inches(2), Inches(9), Inches(2))
data = CategoryChartData(); data.categories = ["T1","T2"]; data.add_series("CA", (120, 180))
slide.shapes.add_chart(XL_CHART_TYPE.COLUMN_CLUSTERED, Inches(1), Inches(2), Inches(8), Inches(4.5), data)

prs.save("deck.pptx")

Inspect a template's layouts first: loop prs.slide_layouts and print placeholder names/indexes.

HTML slide template library

Navin materializes the selected editable HTML deck inside the active workspace (one folder per design: slide_XX.html samples at 1920x1080 + metadata.json + design-system.json + theme.css + image.png preview). The shared engine lives in templates/ppt/_engine.

When the runtime context contains a "Document Template Attachment":

1. ls the template folder; read metadata.json and design-system.json.

2. Write a semantic deck JSON. Then let the engine render every slide. The slide_XX.html files in the theme folder are the lookbook (picker preview). Do not copy them. Do not hand-write HTML. Do not paste { "x", "y", "width" }. Hand-edited HTML is how text doubles and images paint over the copy.

   Image on the left: "layout": "image-text". Image on the right: "text-image". Full bleed: "full-bleed-hero". Process, KPI, timeline, matrix: same ids.

   {
     "theme": "startup",
     "language": "fr",
     "slides": [
       {
         "layout": "cover",
         "kicker": "Pitch",
         "title": "Les equipes perdent 6 h par semaine",
         "body": "Un agent operationnel en 14 jours.",
         "tone": "hero-dark",
         "notes": "Open on the wasted hours. Do not read the title."
       },
       {
         "layout": "text-image",
         "title": "Le produit tient la promesse",
         "body": "Un ecran, un resultat mesure.",
         "items": [
           { "label": "14 jours", "detail": "Premier agent en production." },
           { "label": "1 equipe", "detail": "Pas un projet IT de 9 mois." }
         ],
         "visual": { "type": "image", "kind": "screenshot", "position": "right", "fit": "contain" },
         "image": "product.png"
       }
     ]
   }
   

   <navin-python> -m navin.documents.ppt_design deck --slides deck.json -o slides/
   

   One slide only:

   <navin-python> -m navin.documents.ppt_design materialize --theme <name> --slide slide.json -o slides/slide_03.html
   

   The renderer builds the body from scratch. Sample phrases and image.png never survive. If there is no real image, a theme panel fills that column: no empty frame, no leftover placeholder. A content slide that is only a title and one sentence is a defect. Emit at least three items, a process, a KPI row, or a real photo. From three content slides up, the engine inserts an agenda sommaire after the cover, built from the real titles. Do not skip it. Set language on the deck JSON so the kicker reads Sommaire or Agenda. From eight content slides up it also inserts a section-break curtain and promotes a data hero if you forgot. A gallery is added when two or more real photos exist. Tones (light / dark / hero) are filled so the deck is not all-paper. deck also writes index.html (S = presenter: current, next, notes, timer; O = overview), notes.json and critique.json. Do not deliver when critique is under 85. html2pptx.py copies the speaker notes stamped on each slide into the PPTX; the separate ppt_design notes --dir slides/ --pptx deck.pptx command only serves a deck converted some other way. Layout names are tolerant (bullets, title, thanks, kpis... map to catalog ids; ppt_design layouts lists them) but write the real ids.

   The PPTX stays editable. The HTML preview is extra, never a screenshot substitute for the file. Colors come from --nv-* tokens. Never invent a new hex.

   Visuals follow ppt_assets (see presentation-designer). Never download from Google Images. Numbers become native charts. Simple process graphics may stay native SVG. Architecture, sequence, workflow and data-flow diagrams use archify (export PNG/SVG onto the slide). Photos come from Unsplash / Pexels / Pixabay only, cached with author metadata. Icons come from Lucide (then Tabler, Heroicons, Simple Icons) as SVG tinted with the theme accent. User files win. cover for photos, contain for screenshots and logos. Never stretch.

3. Pick data-variant from _engine/catalog.json (process, cycle, timeline, funnel, matrix, kpi, chart, table, …). Step counts stay between the catalog min and max (process: 2 to 10).

4. Convert with the bundled converter:

   <navin-python> .navin/resources/tools/html2pptx.py slides/ -o deck.pptx
   

   Chromium measures the rendered page, then every text becomes a text box, every solid block a shape, every local image a picture, and only the remaining decor (gradients, SVG, shadows) is flattened behind them. Roughly one second per slide. Useful flags: --keep-fonts to keep the CSS font names instead of their Office equivalents, --chromium PATH when no browser is found, --keep-workdir DIR to inspect the intermediate files.

5. Never restyle the template; adapt content length to the existing blocks. Keep the template fonts and palette even if you dislike them.

6. QA the slides before converting (see below), fix what it names, run it again. Then read what the converter prints: it reports the defects a reader notices first, and each one is a fix to make in the HTML before delivering: copy running past the 1920x1080 frame (shorten it), text that does not separate from the block behind it (darken the text or lighten the block), the same picture reused across slides (find distinct visuals or drop them).

7. After conversion, run doc_check.py deck.pptx, then preview_document.py deck.pptx previews/ and read the PNGs. Reject the deck if titles are topic-labels, bullets are padded, or slides look like a different brand than the template.

Deliver a PDF instead (or as well) when the user asked for one: <navin-python> .navin/resources/tools/html2pdf.py slides/ -o deck.pdf prints the same slides as 16:9 pages with a real text layer.

Charts stay editable: put the numbers in series or chart in the deck JSON (see "Charts stay editable" below) and the converter places a native chart, never a matplotlib PNG, unless the user wants a pixel-exact figure.

Visual QA (before converting)

Every slide is laid out in Chromium at 1920x1080 - the frame the converter uses - and read the way the room will read it: what runs off the edge, what prints over what, what cannot be read from the back, what carries no title, what chart has no insight line. Each slide comes back scored out of 100 against _engine/quality.json, with the thing to change.

<navin-python> .navin/resources/tools/ppt_qa.py slides/
<navin-python> .navin/resources/tools/ppt_qa.py slides/ --json

It exits non-zero when the weakest slide falls under the declared threshold of 85: one weak slide is the one the room remembers, so an average is not enough. Run it on the filled slides, before converting, because that is the stage where a finding is still one line of HTML away from being fixed. Do not deliver a deck that is still asking for rework.

Two findings fail the deck whatever it scores, because they mean the slide was never written rather than written badly:

• template-copy: the text is still the template's, word for word. Every template declares text_policy: replace_all_visible_text, and QA now checks it by comparing the deck against the template it was copied from. Copying a template and adapting the first slides leaves the rest describing the template's imaginary company.
• empty: filler the template shipped with - lorem in any of its variants, Your title here, a (+62) 000 0000 0000 contact block.
• thin-slide: a content slide that is only a title and one sentence. Cover and statement may do that. Cards, text, process and text-image may not.

Two more are worth knowing in advance, because they are invisible in the preview and only bite once the deck is a PowerPoint file:

• title-not-heading: the slide title must be an h1/h2 (the .nv-title class alone is not enough). The converter puts it in PowerPoint's title placeholder, which is what fills the Outline view and names the slide in the thumbnail panel. A div styled large arrives as an anonymous textbox.
• theme-unlinked: the slide names colours instead of reading tokens, so it cannot change theme. Materialize it with ppt_design.py rather than hand-rolling a palette.

No empty blocks (mandatory)

A template slide holds a fixed number of cards, columns, quotes and figures. Leaving some of them with sample text, a placeholder image or nothing at all is what makes a deck look unfinished.

• Fill every block of a slide with real content, or delete the block from the HTML and rebalance the layout (a 4-card grid becomes a 3-card grid, not three cards and a hole).
• Never ship "Lorem ipsum", "Title here", "XX%", an untouched sample label or an empty image frame.
• Not enough material for a slide? Drop the slide instead of padding it.
• Title + one sentence on text, cards, text-image or process is unfinished. QA flags it as thin-slide. Rewrite with three claims or a visual, then render again.
• A block whose text is much shorter than the sample changes the balance: either write to the intended length or pick a slide layout that fits.

Before delivering

1. Reopen the file and check what it actually contains, not what the script intended:

   from pptx import Presentation
   prs = Presentation("deck.pptx")
   for i, slide in enumerate(prs.slides, 1):
       boxes = [s for s in slide.shapes if s.has_text_frame and s.text_frame.text.strip()]
       chars = sum(len(s.text_frame.text) for s in boxes)
       print(i, "text boxes:", len(boxes), "chars:", chars)
   

   A slide with zero text boxes is a rasterized slide: fix the conversion, do not deliver it.

2. Read the text back for leftover sample copy, source-language strings, em dashes and emoji.

3. Validate the file itself:

   <navin-python> .navin/resources/tools/doc_check.py deck.pptx
   

   It blocks on leftover sample copy, unresolved {{placeholders}}, em dashes, emoji, an empty slide, text off the canvas and a missing title, and warns on thin slides and tiny text. Fix the source and convert again.

4. Look at the deck, do not assume it. The bundled previewer renders the saved file into PNGs and a contact sheet, so read them back with vision:

   <navin-python> .navin/resources/tools/preview_document.py deck.pptx previews/
   

   With LibreOffice installed it is the real render (fonts, charts, pictures); without it, the geometry of every shape is drawn at its true place, which still shows a decor that stops short of the edge, text over text, an empty block or unreadable copy.

5. Every slide of the template you kept has real content. Template captions that explain the layout ("The 'what' defines the products a brand offers") are instructions to you, not copy: replace them with the client's content or delete them.

Charts stay editable

Give the numbers in the deck JSON and the converter builds a native PowerPoint chart (the client can restyle or edit the data in PowerPoint):

{"layout": "chart", "title": "Revenue tripled in three years", "insight": "+43% year on year",
 "series": [{"label": "2024", "value": "1.9M"}, {"label": "2025", "value": "2.8M"}, {"label": "2026", "value": "3.6M"}]}

Several series or another type use chart:

{"layout": "chart", "title": "EMEA leads on margin", "insight": "41% in Q4",
 "chart": {"type": "line", "categories": ["Q1", "Q2", "Q3", "Q4"],
           "series": [{"name": "EMEA", "values": [31, 34, 36, 41]}, {"name": "Americas", "values": [22, 25, 27, 29]}],
           "number_format": "0\"%\""}}

Types: column, bar, stacked-column, stacked-bar, line, area, stacked-area, pie, doughnut, radar. The HTML preview draws the same chart (bars, polyline or donut) so ppt_qa and the PDF print see what the PPTX will hold. A chart the user wants pixel-exact stays an image.

The user's own .pptx

When the user hands over their company deck, it is the design. Do not redraw it:

<navin-python> .navin/resources/tools/office_template.py inspect brand.pptx      # layouts, placeholders, theme fonts and colours
<navin-python> .navin/resources/tools/office_template.py build brand.pptx --slides deck.json -o deck.pptx
<navin-python> .navin/resources/tools/office_template.py fill brand.pptx --data values.json -o deck.pptx   # {{key}} placeholders

build adds slides on the template's own layouts (title, subtitle, bulleted body with levels, picture, table, notes) and drops the sample slides unless --keep-slides is passed. Then doc_check and preview_document as above.

Workflow

1. Get the validated slide plan (one message per slide) from presentation-designer.
2. Use the brand template from template-manager when it exists.
3. Generate slide by slide from a structured dict/JSON - the script stays rerunnable under build/, and out of the reply.
4. QA the slides with ppt_qa.py, fix the findings, run it again until it passes.
5. Convert, stamp speaker notes, open slides/index.html to flip through the deck, then run the delivery checks above.

Rules

• One idea per slide; ≤6 bullets, ≤10 words each - push data to charts.
• Numbers get big-figure treatment, not buried in sentences.
• Charts as native pptx charts when they need to stay editable; as images when they must be pixel-exact.