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

Markdown	Gamma role
# H1	Title card — use exactly once at the top
## H2	New card title
### H3	Section header within a card
#### H4	Sub-section / column header

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

Card Length Budget

Card type	Body words	Bullet count
Title / section divider	0–10	0
Content card (16:9)	40–80	3–5
Detail / data card	80–140	5–8
Appendix card	up to 200	8–12

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:

Pattern	When to use
	Exact image you control
![A photorealistic close-up of a chess piece on a marble board, dramatic side lighting]() (empty src)	Let Gamma's AI generate from your alt text
<!-- gamma-image: cinematic shot, low-angle, golden hour, no text --> (HTML comment marker)	Hint for the chat agent to swap later — placeholder card uses theme default

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

Goal	Prompt template
Tighten a wordy card	"Condense this card to 3 bullets, keep the data point"
Regenerate one image	"Replace this image with a wide cinematic shot, low-angle, no people"
Restyle whole deck	"Apply a more conservative tone — dark navy theme, serif headings, minimal images"
Add a missing card	"Insert a 'Next Steps' card after Pricing with 4 owner/date bullets"
Fix imbalance	"Card 6 is much denser than the others — split it into two"
Translate	"Translate the deck to Brazilian Portuguese, keep the data labels in English"
Generate speaker notes	"Add 2-sentence speaker notes to every card that has data"
Add data viz	"Convert this table into a horizontal bar chart, sorted descending"

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:

Issue detected	Recommendation to user
First card has more than a title	"Add a one-sentence promise under the H1 — Gamma's title card looks empty otherwise"
Any card body > 140 words	"Card N is too dense for a 16:9 slide — split or move detail to an appendix toggle"
No ![]() image directives	"No image prompts found — Gamma will use stock images. Add 2-3 alt-text prompts for hero cards"
No speaker notes	"Add <!-- Speaker note: ... --> blocks for talking points — they export to PPTX"
No appendix	"Add ## Appendix with <details> toggles for methodology and data sources"
Heading levels skip (H1 → H3)	"Heading hierarchy skips a level — Gamma's outline will look broken"
Identical bullet counts across all cards	"Vary card density — uniform cards feel monotonous; mix bullets, tables, callouts, images"
All-text deck with --image-model set	"No ![]() directives but image-model is set — generation will be expensive without alt-text guidance"

---

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