gbb-pptx

name: gbb-pptx description: > Generate professional PowerPoint (PPTX) presentations using python-pptx (the AI Apps GBB dark/light pitch-deck generator). USE FOR: create PowerPoint, generate PPTX, make slide deck, build presentation, convert markdown to slides, pitch deck, report as PPTX, create slides, gbb-pptx, gbb deck, dark-themed deck. DO NOT USE FOR: editing existing PPTX files (use the upstream `pptx` skill), PDF generation, Google Slides. metadata: version: "2.0.1"

GBB PPTX Deck Generator Skill

Renamed from pptx in v2.0.0 to avoid name collision with the upstream Anthropic-style pptx skill (which focuses on reading/editing existing .pptx files via markitdown). This GBB variant generates fresh dark/light-themed pitch decks from Markdown using python-pptx. Both can coexist at user scope — invoke this one with the gbb-pptx / "GBB deck" / "dark-themed deck" trigger phrases.

Generate professional, dark-themed PowerPoint (PPTX) presentations using python-pptx.

When to Use

Invoke this skill when the user asks to:

Create a PowerPoint / PPTX presentation
Generate a slide deck
Convert markdown content into slides
Build a pitch deck or report as PPTX

Prerequisites

pip install python-pptx

How It Works

Define slide content — either from user instructions or by reading a markdown file
Generate a Python script using the patterns below
Run the script to produce the .pptx file

Core Patterns

Slide Setup (16:9 Widescreen)

from pptx import Presentation
from pptx.util import Inches, Pt
from pptx.dml.color import RGBColor
from pptx.enum.text import PP_ALIGN
from pptx.enum.shapes import MSO_SHAPE

prs = Presentation()
prs.slide_width = Inches(13.333)   # 16:9
prs.slide_height = Inches(7.5)

Background Color

def set_bg(slide, color):
    fill = slide.background.fill
    fill.solid()
    fill.fore_color.rgb = color

Text Box

def text_box(slide, left, top, width, height, text,
             font_size=14, color=RGBColor(0xF1,0xF5,0xF9),
             bold=False, align=PP_ALIGN.LEFT, font="Segoe UI"):
    box = slide.shapes.add_textbox(
        Inches(left), Inches(top), Inches(width), Inches(height))
    box.text_frame.word_wrap = True
    p = box.text_frame.paragraphs[0]
    p.text = text
    p.font.size = Pt(font_size)
    p.font.color.rgb = color
    p.font.bold = bold
    p.font.name = font
    p.alignment = align
    return box

Bullet List

def bullet_list(slide, left, top, width, height, items,
                font_size=14, color=RGBColor(0xF1,0xF5,0xF9)):
    box = slide.shapes.add_textbox(
        Inches(left), Inches(top), Inches(width), Inches(height))
    tf = box.text_frame
    tf.word_wrap = True
    for i, text in enumerate(items):
        p = tf.paragraphs[0] if i == 0 else tf.add_paragraph()
        p.text = f"▸  {text}"
        p.font.size = Pt(font_size)
        p.font.color.rgb = color
        p.font.name = "Segoe UI"
        p.space_before = Pt(14)
    return box

Rounded Rectangle Card

def card(slide, left, top, width, height,
         fill=RGBColor(0x16,0x20,0x36),
         border=RGBColor(0x1E,0x29,0x3B)):
    shape = slide.shapes.add_shape(
        MSO_SHAPE.ROUNDED_RECTANGLE,
        Inches(left), Inches(top), Inches(width), Inches(height))
    shape.fill.solid()
    shape.fill.fore_color.rgb = fill
    shape.line.color.rgb = border
    shape.line.width = Pt(1)
    return shape

Accent Bar (decorative line)

def accent_bar(slide, left, top, width=1.2, height=0.055,
               color=RGBColor(0x38,0x9F,0xF7)):
    s = slide.shapes.add_shape(
        1, Inches(left), Inches(top), Inches(width), Inches(height))
    s.fill.solid()
    s.fill.fore_color.rgb = color
    s.line.fill.background()

Speaker Notes

def add_notes(slide, text):
    slide.notes_slide.notes_text_frame.text = text

Polish pass (optional but recommended). Speaker notes are pure prose read aloud during the demo — AI-prose tells degrade credibility. After the deck is assembled, run gbb-humanizer over the notes text using the pre-canned gbb-seller-pitch.md voice sample. Do not humanize slide bullets or titles — those need to stay punchy and parallel; the humanizer's section-aware mode skips them by default.

Save with Lock Detection

import os, time
out = "output.pptx"
if os.path.exists(out):
    try:
        with open(out, "ab"): pass
    except PermissionError:
        ts = time.strftime("%Y%m%d-%H%M%S")
        out = f"output-{ts}.pptx"
prs.save(out)

Theme Presets

Dark Navy (ThreadLight style)

BG      = RGBColor(0x0F, 0x17, 0x2A)  # Background
CARD    = RGBColor(0x16, 0x20, 0x36)  # Card fill
BLUE    = RGBColor(0x38, 0x9F, 0xF7)  # Primary accent
CYAN    = RGBColor(0x06, 0xB6, 0xD4)  # Secondary accent
WHITE   = RGBColor(0xF1, 0xF5, 0xF9)  # Primary text
MUTED   = RGBColor(0x94, 0xA3, 0xB8)  # Secondary text
DIM     = RGBColor(0x64, 0x74, 0x8B)  # Tertiary text
GREEN   = RGBColor(0x22, 0xC5, 0x5E)  # Success
AMBER   = RGBColor(0xF5, 0x9E, 0x0B)  # Warning/highlight
RED     = RGBColor(0xEF, 0x44, 0x44)  # Error/negative

Light Corporate

BG      = RGBColor(0xFF, 0xFF, 0xFF)
CARD    = RGBColor(0xF8, 0xFA, 0xFC)
BLUE    = RGBColor(0x00, 0x78, 0xD4)  # Microsoft Blue
WHITE   = RGBColor(0x1A, 0x1A, 0x2E)  # Dark text on light
MUTED   = RGBColor(0x60, 0x60, 0x60)

Slide Layout Recipes

Title Slide

Accent bar at ~30% from top
Title: 44-48pt bold
Tagline: 20-22pt accent color
Subtitle: 14pt muted
Footer: 11pt dim at bottom

Content Slide with Bullets

Accent bar at top-left
Title: 28-30pt bold
Bullet list: 14-15pt with ▸ prefix and 14-18pt spacing
Optional highlight quote at bottom in accent color

Two-Column Comparison

Two side-by-side cards (each ~5.4" wide on 16:9)
Column headers in accent colors
✓ / ✗ prefixes for positive / negative items

Card Grid (2×3 or 2×2)

Cards with title (accent color, bold) + description (muted)
Column spacing: x = margin + col * card_pitch

Timeline / Steps

Numbered badge cards (accent fill)
Title + description on same row
Optional time value right-aligned

Tips

Use Inches() for all positioning — never raw EMU values
16:9 canvas is 13.333 × 7.5 inches; keep content within 1" margins
Font hierarchy: Title 28-48pt → Heading 16-20pt → Body 12-15pt → Caption 10-11pt
Use word_wrap = True on all text frames
Keep text boxes slightly taller than needed to prevent clipping
Test with python -c "from pptx import Presentation; ..." to validate
For locked files (open in PowerPoint), auto-version the output filename

Example: Complete Slide

slide = prs.slides.add_slide(prs.slide_layouts[6])  # blank layout
set_bg(slide, BG)
accent_bar(slide, 1, 0.6)
text_box(slide, 1, 0.8, 11, 0.6, "Slide Title Here", 30, WHITE, True)
bullet_list(slide, 1, 1.7, 11, 4, [
    "First bullet point with key insight",
    "Second bullet point with supporting data",
    "Third bullet point with call to action",
], 15, WHITE)
card(slide, 1, 5.5, 11.3, 1)
text_box(slide, 1.4, 5.65, 10.5, 0.7,
         '"Closing quote or key takeaway"', 14, CYAN)
add_notes(slide, "Speaker notes with source links here")
prs.save("output.pptx")

Skill	Use When
gbb-humanizer	Polish pass for speaker notes after the deck is generated. Section-aware mode skips slide bullets and titles (which need to stay punchy and parallel) and only rewrites the prose inside `notes_slide.notes_text_frame.text`. Use the pre-canned `gbb-seller-pitch.md` voice sample.
threadlight-design	Generates the SpecKit + `overview.html` that this deck's slides typically narrate — the deck is often a re-projection of the same content for an audience that prefers slides to long-form HTML.

GBB PPTX Deck Generator Skill

When to Use

Prerequisites

How It Works

Core Patterns

Slide Setup (16:9 Widescreen)

Background Color

Text Box

Bullet List

Rounded Rectangle Card

Accent Bar (decorative line)

Speaker Notes

Save with Lock Detection

Theme Presets

Dark Navy (ThreadLight style)

Light Corporate

Slide Layout Recipes

Title Slide

Content Slide with Bullets

Two-Column Comparison

Card Grid (2×3 or 2×2)

Timeline / Steps

Tips

Example: Complete Slide

See Also