jwynia/pptx-generator
Create and manipulate PowerPoint PPTX files programmatically. Use when the user needs to generate presentations, modify PPTX templates, extract slide content, create thumbnail previews, or automate PowerPoint workflows. Supports both template-based generation (for branding compliance) and from-scratch creation. Keywords: PowerPoint, PPTX, presentation, slides, template, deck, slideshow, corporate, branding.
npx skills add https://github.com/jwynia/agent-skills --skill pptx-generatorUse this skill when:
Do NOT use this skill when:
{{PLACEHOLDERS}} and replace with contentExtract text inventory to understand what can be replaced:
deno run --allow-read scripts/analyze-template.ts corporate-template.pptx > inventory.json
Output (inventory.json):
{
"filename": "corporate-template.pptx",
"slideCount": 10,
"textElements": [
{
"slideNumber": 1,
"shapeId": "shape-2",
"shapeName": "Title 1",
"placeholderType": "ctrTitle",
"position": { "x": 1.5, "y": 2.0, "w": 7.0, "h": 1.2 },
"paragraphs": [
{ "text": "{{TITLE}}", "fontSize": 44, "bold": true }
]
}
]
}
Create replacements.json:
{
"textReplacements": [
{ "tag": "{{TITLE}}", "value": "Q4 2024 Results" },
{ "tag": "{{SUBTITLE}}", "value": "Financial Overview" },
{ "tag": "{{DATE}}", "value": "December 2024" },
{ "tag": "{{AUTHOR}}", "value": "Finance Team", "slideNumbers": [1] }
]
}
deno run --allow-read --allow-write scripts/generate-from-template.ts \
corporate-template.pptx replacements.json output.pptx
Get information about available slides:
deno run --allow-read scripts/generate-thumbnails.ts slide-library.pptx
For visual preview, extract the thumbnail:
deno run --allow-read --allow-write scripts/generate-thumbnails.ts \
slide-library.pptx --extract-thumb --output-dir ./previews
Create selections.json:
{
"slideSelections": [
{ "slideNumber": 1 },
{ "slideNumber": 5 },
{ "slideNumber": 12 },
{ "slideNumber": 3 }
],
"textReplacements": [
{ "tag": "{{TITLE}}", "value": "Custom Presentation" }
]
}
deno run --allow-read --allow-write scripts/generate-from-template.ts \
slide-library.pptx selections.json custom-deck.pptx
Create spec.json:
{
"title": "Product Launch 2025",
"author": "Marketing Team",
"slides": [
{
"background": { "color": "003366" },
"elements": [
{
"type": "text",
"x": 1, "y": 2.5, "w": 8, "h": 1.5,
"options": {
"text": "Product Launch 2025",
"fontSize": 44,
"bold": true,
"color": "FFFFFF",
"align": "center"
}
},
{
"type": "text",
"x": 1, "y": 4, "w": 8, "h": 0.5,
"options": {
"text": "Revolutionizing the Industry",
"fontSize": 24,
"color": "CCCCCC",
"align": "center"
}
}
]
},
{
"elements": [
{
"type": "text",
"x": 0.5, "y": 0.5, "w": 9, "h": 0.7,
"options": {
"text": "Key Features",
"fontSize": 32,
"bold": true,
"color": "003366"
}
},
{
"type": "table",
"x": 0.5, "y": 1.5, "w": 9, "h": 3,
"options": {
"rows": [
["Feature", "Description", "Benefit"],
["Speed", "2x faster processing", "Save time"],
["Quality", "HD output", "Better results"],
["Integration", "Works with existing tools", "Easy adoption"]
],
"border": { "pt": 1, "color": "CCCCCC" }
}
}
]
}
]
}
deno run --allow-read --allow-write scripts/generate-scratch.ts spec.json output.pptx
Scenario: Generate quarterly report from branded template.
Steps:
# 1. Analyze template for replaceable content
deno run --allow-read scripts/analyze-template.ts quarterly-template.pptx --pretty
# 2. Create replacements.json with Q4 data
# 3. Generate report
deno run --allow-read --allow-write scripts/generate-from-template.ts \
quarterly-template.pptx replacements.json Q4-2024-Report.pptx
Scenario: Combine approved slides for a specific client pitch.
Steps:
# 1. View available slides
deno run --allow-read scripts/generate-thumbnails.ts pitch-library.pptx
# 2. Create selections.json picking slides 1, 3, 7, 12, 15
# 3. Generate custom deck
deno run --allow-read --allow-write scripts/generate-from-template.ts \
pitch-library.pptx selections.json acme-pitch.pptx
Scenario: Generate presentation from JSON data (e.g., API response).
Steps:
# 1. Transform your data into spec.json format
# 2. Generate presentation
deno run --allow-read --allow-write scripts/generate-scratch.ts data-spec.json report.pptx
| Script | Purpose | Permissions |
|--------|---------|-------------|
| analyze-template.ts | Extract text inventory from PPTX | --allow-read |
| generate-thumbnails.ts | Get slide info and extract previews | --allow-read --allow-write |
| generate-from-template.ts | Modify templates (replace/combine) | --allow-read --allow-write |
| generate-scratch.ts | Create PPTX from JSON specification | --allow-read --allow-write |
| Type | Description | Key Options |
|------|-------------|-------------|
| text | Text box | text, fontSize, bold, color, align |
| image | Image from file or base64 | path, data, sizing |
| table | Data table | rows, colW, border, fill |
| shape | Geometric shapes | type, fill, line, text |
| chart | Charts and graphs | type, data, title, showLegend |
Symptoms: Output PPTX still contains {{PLACEHOLDER}} tags.
Solution:
analyze-template.ts to verify exact tag textslideNumbers filter in replacementsSymptoms: Slides appear in wrong order after combining.
Solution:
slideSelectionsSymptoms: Image elements are blank in output.
Solution:
Understanding how PowerPoint's OOXML format handles placeholders is crucial for template development.
PowerPoint uses a hierarchical inheritance model:
Theme → Slide Master → Slide Layout → Slide
{{placeholder}} text in a layout does NOT automatically appear on slides using that layout.<a:lstStyle/>, it inherits formatting (color, size, bullets) from the layout's <a:lstStyle>.<p:ph type="..." idx="..."/>. The type (e.g., "title", "body", "ctrTitle") and idx must match.<a:buNone/> in the layout's lstStyle.In layout placeholders, define colors in <a:lstStyle> (inheritable), not in <a:rPr> (run-specific):
<!-- Layout: Color in lstStyle (GOOD - inheritable) -->
<p:txBody>
<a:lstStyle>
<a:lvl1pPr algn="ctr">
<a:buNone/> <!-- Suppress bullets -->
<a:defRPr sz="4400" b="1">
<a:solidFill><a:srgbClr val="FFFFFF"/></a:solidFill>
</a:defRPr>
</a:lvl1pPr>
</a:lstStyle>
<a:p>
<a:r><a:rPr lang="en-US"/><a:t>{{placeholder}}</a:t></a:r>
</a:p>
</p:txBody>
For slides to properly inherit from layouts:
<!-- Slide: Empty lstStyle to inherit from layout -->
<p:sp>
<p:nvSpPr>
<p:cNvPr id="2" name="title 2"/>
<p:cNvSpPr><a:spLocks noGrp="1"/></p:cNvSpPr>
<p:nvPr>
<p:ph type="ctrTitle"/> <!-- Links to layout placeholder -->
</p:nvPr>
</p:nvSpPr>
<p:spPr/> <!-- Empty = inherit position from layout -->
<p:txBody>
<a:bodyPr/>
<a:lstStyle/> <!-- Empty = inherit formatting from layout -->
<a:p>
<a:r>
<a:rPr lang="en-US"/> <!-- Empty = inherit character formatting -->
<a:t>{{placeholder}}</a:t> <!-- Content must be here -->
</a:r>
</a:p>
</p:txBody>
</p:sp>
| Issue | Cause | Solution |
|-------|-------|----------|
| Text shows as black instead of white | Color defined in <a:rPr> not <a:lstStyle> | Move color to layout's <a:defRPr> in <a:lstStyle> |
| Unwanted bullets appearing | Master's bodyStyle has bullets, layout doesn't override | Add <a:buNone/> to layout's <a:lvl1pPr> |
| Placeholder text not appearing | Text only in layout, not in slide | Include text content in slide's <p:txBody> |
| Formatting not applying | Slide has explicit formatting | Use empty <a:lstStyle/> and <a:rPr lang="en-US"/> |
| Type | Usage |
|------|-------|
| ctrTitle | Centered title (title slides) |
| title | Standard title |
| subTitle | Subtitle |
| body | Content area (use idx for multiple) |
| pic | Picture placeholder |
| dt | Date/time |
| ftr | Footer |
| sldNum | Slide number |
Take jwynia/pptx-generator from the repository into ~/.claude/skills for personal
use, or into .claude/skills inside a project.
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same name cannot sit side by side — one of them will be ignored.