sg-build

name	sg-build
description	Assemble final PowerPoint (.pptx) from presentation markdown and generated images. Use when you want to create the final PowerPoint, build the deck after image generation, or skip to building from presentation.md.
argument-hint	<presentation.md> [--template generic] [--style style.json]
allowed-tools	Bash, Read, Glob, Grep

Slide Generator: Build Step

Assemble the final PowerPoint file (.pptx) from the presentation markdown and generated images. Uses python-pptx to create a professional slide deck with the selected template.

Pre-loaded Context

Working directory: !pwd

Available presentation files: !ls -la *.md 2>/dev/null | grep -i pres || echo "No presentation files found"

Available images: !ls images/ 2>/dev/null | wc -l || echo "0"

Available templates: !sg list-templates 2>&1 || echo "Cannot list templates"

Prerequisites

• Preflight: sg --version must succeed before proceeding — if sg is missing, stop and tell the user this requires the private davistroy/slide-generator engine (owner-only; see ADR-0008)
• slide-generator package installed
• A presentation.md file with slide content
• Generated images in images/ directory (optional — builds without images if missing)

Input Validation

Required:

• <presentation.md> - Path to presentation markdown file

Optional:

• --template <name> - Template to use (default: generic). Use sg list-templates to see options
• --style <path> - Custom style JSON file for colors, fonts, sizing
• --output <path> - Output .pptx file path

Instructions

1. Verify input: Confirm presentation markdown and images exist
2. List templates (if user hasn't specified):

   sg list-templates
   

3. Run build:

   sg build presentation.md --template generic
   

4. Verify output: Confirm .pptx file was created
5. Report results: Show file path, file size, slide count

How It Works

The build step:

• Parses markdown into structured slide data (titles, bullets, notes, image refs)
• Classifies each slide type (title, content, two-column, image-heavy, etc.)
• Applies template layout rules for each slide type
• Embeds generated images at appropriate positions
• Adds speaker notes, slide numbers, and footers
• Uses dynamic year detection for copyright footers

Error Handling

Error	Cause	Fix
Template not found	Invalid template name	Run sg list-templates
No slides parsed	Malformed markdown	Check presentation.md format
Image not found	Missing image file	Re-run sg generate-images or use --skip-images
python-pptx error	Template corruption	Try a different template

Output

The build step produces:

• A .pptx PowerPoint file ready for presentation
• File is named based on the topic or output flag

Custom Templates

Install custom templates to ~/.slide-generator/templates/<name>/:

• Must contain a .pptx template file
• Optional template.py extending PresentationTemplate
• Optional style.json for color/font configuration