Gamma Presentation

Gamma Presentation Authoring

Staleness Watch: See EXTERNAL-API-REGISTRY.md for source URLs and recheck cadence

This skill teaches you to write markdown that imports cleanly into Gamma, then refine the result using Gamma's in-app AI chat agent. Two workflows are supported:

1. API workflow — .github/muscles/gamma-generator.cjs posts directly to the Gamma API (one-shot)
2. Manual workflow — author the file in VS Code → paste/upload into Gamma UI → refine with the agent (recommended for high-stakes decks)

Choose manual when the user wants creative control over layout, image style, and theme. Choose API when speed matters more than polish.

Authoring Rules

Card Breaks Are ---

Each --- (markdown horizontal rule on its own line, blank line above and below) becomes a new card. Cards are Gamma's slide unit. Without explicit ---, Gamma's importer auto-splits unpredictably.

# Quarterly Review

Opening card content.

---

## Revenue

Second card.

---

## Next Steps

Third card.

Rule of thumb: One core idea per card. If a card needs scrolling at 16:9, split it.

Heading Hierarchy

Do not skip levels. # Title → ## Card → ### Section keeps the importer's outline correct.

Card Length Budget

Long-form documents (mode document) tolerate more; presentations should breathe.

Speaker Notes

Gamma reads HTML comments as speaker notes:

## Pricing Strategy

We're moving to tiered pricing in Q3.

<!-- Speaker note: Emphasize the migration window. Reference the Q2 churn data
when asked. Do not commit to a launch date — legal review pending. -->

Notes are hidden in published view, exported in PPTX speaker-notes panel.

Image Directives

Three patterns, in order of fidelity:

Write alt-text prompts as if briefing a photographer: subject, framing, lighting, mood, what to exclude (no text, no people, no logos).

Tables

Standard pipe tables import as Gamma tables:

| Tier | Price | Seats |
|---|---|---|
| Starter | $29/mo | 5 |
| Pro | $99/mo | 25 |
| Enterprise | Custom | Unlimited |

Keep ≤ 5 columns, ≤ 8 rows per card. Wider tables → split or move to appendix.

Charts

Gamma renders simple data via its chart card. To hint the importer, use a fenced block labelled chart with TSV/CSV:

```chart
type: bar
title: Revenue by Quarter
Q1	120
Q2	145
Q3	180
Q4	210
```

For complex visualizations, generate the chart externally (data-visualization skill) and embed as an image.

Columns / Multi-Column Layouts

Gamma's importer recognizes a 2- or 3-column layout from ### siblings within a card:

## Comparison

### Old Approach
- Manual ticketing
- Email follow-up
- 5-day SLA

### New Approach
- Auto-routed
- Slack threads
- 4-hour SLA

The card renders as side-by-side columns. Keep parallel structure (same bullet count).

Callouts

Use blockquote with a leading emoji to trigger Gamma's callout card style:

> 💡 **Insight**: 73% of churned customers never opened the onboarding email.

> ⚠️ **Risk**: API rate limits cap us at 12K syncs/hour during the launch window.

Toggles / Collapsibles

For appendix detail that shouldn't crowd the main flow, use HTML <details>:

<details>
<summary>Methodology</summary>

We surveyed 1,240 users across 3 cohorts between Jan and Mar 2026...

</details>

Gamma renders these as expandable toggles.

Document Skeleton

Every well-formed Gamma source follows this shape:

# {Deck Title}

{One-sentence promise of what the audience will learn.}

<!-- Speaker note: Audience = {who}. Goal = {what they should do next}.
Tone = {confident / exploratory / instructive}. -->

---

## Agenda

1. The problem
2. What we did
3. What changed
4. What's next

---

## {Section 1 Title}

{Body — 40-80 words or 3-5 bullets.}

![Illustrative image alt text — describe scene, lighting, mood]()

---

{... more cards ...}

---

## Recommendation

> 💡 **Bottom line**: {one sentence}

---

## Appendix

<details>
<summary>Methodology</summary>
...
</details>

<details>
<summary>Data sources</summary>
...
</details>

Always end with an Appendix section using <details> toggles for backup data, methodology, glossary, and FAQs. The audience sees a clean main flow; the presenter has depth on demand.

Workflow A: Manual (Recommended for High-Stakes Decks)

1. Draft the markdown file using the skeleton above. Keep it under 75 cards (Gamma's import limit).

2. Pre-process with the preprocessor muscle to auto-insert card breaks, demote stray H1s, and flag dense cards / weak alt-text:

   node .github/muscles/md-to-gamma.cjs ./deck.md
   # writes ./deck-gamma.md with inline <!-- Gamma: ... --> recommendations
   

   Or right-click any .md in VS Code Explorer → Convert Markdown → Gamma (preprocess).

3. Validate locally: render to HTML (md-to-html skill) or PPTX (md-to-word → PowerPoint) to sanity-check structure before paying for credits.

4. Import to Gamma:

   • Open https://gamma.app → Create new → Import → paste markdown or upload <name>-gamma.md
   • Choose theme + page format (16:9 fixed for presentations, fluid for docs)
   • Click Generate

5. Refine via chat agent (see next section)

6. Export as PPTX or PDF

This workflow gives the user control over theme, brand, and per-card image direction.

Workflow B: API One-Shot

Use .github/muscles/gamma-generator.cjs when speed matters and the user is okay with the default theme:

node .github/muscles/gamma-generator.cjs --file ./deck.md --slides 12 --dimensions 16x9 --export pptx --open

Always pass --slides N and --dimensions 16x9 for presentations. Without them, Gamma auto-splits and may default to fluid layout.

For draft-then-edit workflow:

# 1. Generate draft markdown
node .github/muscles/gamma-generator.cjs --topic "Q2 review" --draft --draft-output ./q2.md

# 2. User edits q2.md in VS Code

# 3. Generate final
node .github/muscles/gamma-generator.cjs --file ./q2.md --slides 14 --dimensions 16x9 --export pptx --open

Full parameter reference: see instructions/gamma-presentation.instructions.md.

Refining with Gamma's Chat Agent

Once the deck is open in Gamma's editor, the sparkle icon ✨ opens the AI chat agent. It can edit any card, regenerate images, restyle the whole deck, translate, and add new cards.

Effective Agent Prompts

Agent Strengths vs Limits

Agent does well:

• Per-card edits (text, images, layout)
• Theme application across deck
• Adding individual cards from a topic
• Translation and tone shifts
• Restyling images consistently

Agent struggles with:

• Multi-card structural rewrites (do those in markdown, re-import)
• Embedded chart data corrections (edit source data, regenerate)
• Brand asset injection (upload assets to workspace first)
• Cross-card narrative consistency (you stay the editor here)

Rule: Use markdown for structure, agent for polish. If you find yourself re-prompting the agent 4+ times for the same card, the source markdown is wrong — fix it there and re-import.

Recommendations to Surface to the User

When generating or reviewing a Gamma source file, proactively call out these issues:

Cost Awareness

Default 10-card deck with standard images: 80–150 credits (~$1.50–3 on Pro plans).

Tier the image model to deck importance:

• Throwaway / iteration: flux-quick (2 credits)
• Standard work: flux-pro (10 credits) — recommended default
• Client-facing: imagen4 or recraft (25 credits)
• Hero deck: flux-ultra or gpt-image-hd (75–125 credits)

Full model table in instructions/gamma-presentation.instructions.md.

Related

• instructions/gamma-presentation.instructions.md — auto-loaded routing + muscle parameters
• prompts/gamma.prompt.md — /gamma command reference
• muscles/md-to-gamma.cjs — markdown preprocessor (name.md → name-gamma.md); also surfaced as Convert Markdown → Gamma (preprocess) in the VS Code right-click menu
• muscles/gamma-generator.cjs — API runner (one-shot generation)
• skills/presentation-tool-selection — Marp vs Gamma vs manual decision matrix
• skills/data-visualization — produce chart images for embed
• skills/markdown-mermaid — diagrams that survive Gamma import
• skills/brand-asset-management — upload brand assets to Gamma workspace before generation