Gamma

Gamma Generate API

What this skill really does

Gamma's Generate API (v1.0, GA since Nov 2025) creates a Gamma (presentation / document / social / webpage) from text — a one-line prompt up to ~400k characters of content — and can export it to PDF, PPTX or PNG. It is a generation-only API: you send input text, poll for completion, and get a shareable gammaUrl plus an optional exportUrl.

It is asynchronous and one-shot per generation. There is no slide-by-slide edit API, no "outline" endpoint, no templates endpoint. (The previous version of this skill documented api.gamma.app/v1/generate, /v1/presentations, update_slide, list_templates — none of those exist. They were removed.)

Helper: scripts/gamma_client.py (correct endpoints, verified against the live API).

Status / honesty notes (verified 2026-07-22)

• Base URL, path and header below were probed live and are correct (a bad key returns HTTP 401 Invalid API key, i.e. the request reaches the real endpoint).
• ⚠️ The GAMMA_API_KEY stored in ~/.claude/.credentials.master.env currently returns 401 Invalid API key — it is expired/revoked or on the wrong plan. GAMMA_API_KEY_2 is a broken placeholder (os.getenv(...)), ignore it.
• Before anything works: regenerate a key at gamma.app → Settings → API keys (needs a paid plan: Pro / Ultra / Teams / Business) and replace GAMMA_API_KEY.
• Fields marked "(unverified)" below are from Gamma's docs but were not exercised with a live generation here. Treat exact allowed-value lists as best-effort, not gospel.

API surface

Request body (POST /v1.0/generations)

Response: { "generationId": "..." }.

Poll response (GET /v1.0/generations/{generationId})

• status: pending → completed | failed
• on completed: gammaUrl, gammaId, exportUrl (present only if exportAs was set), credits.deducted, credits.remaining
• rate-limit headers: x-ratelimit-remaining, x-ratelimit-remaining-burst, x-ratelimit-remaining-daily. Poll every ~5 s.
• export URLs expire in ~1 week and are public-with-link.

Procedure

1. Ensure a valid GAMMA_API_KEY (see status notes). Quick auth check: curl -s -o /dev/null -w "%{http_code}\n" -H "X-API-KEY: $GAMMA_API_KEY" \ https://public-api.gamma.app/v1.0/generations/x — expect 404 (key OK) vs 401 (bad key).
2. Build inputText. For tighter control, pass a structured outline and use textMode: preserve or condense instead of generate.
3. POST /v1.0/generations; keep the generationId.
4. Poll GET /v1.0/generations/{generationId} every ~5 s until completed/failed.
5. Use gammaUrl (view/share) and exportUrl (download, if exportAs set).

Output

• gammaUrl — editable/shareable Gamma
• exportUrl — PDF/PPTX/PNG download (only when exportAs requested)
• gammaId, credits deducted/remaining

Usage — helper script

# generate + wait for completion + export to pptx
python ~/.claude/skills/gamma/scripts/gamma_client.py generate \
  "AI in Healthcare: trends, applications, and outlook" \
  --format presentation --num-cards 10 --export pptx \
  --tone professional --audience "hospital executives" --wait

# poll an existing generation
python ~/.claude/skills/gamma/scripts/gamma_client.py poll <generationId> --wait

Usage — raw curl

KEY="$GAMMA_API_KEY"
GEN=$(curl -s -X POST https://public-api.gamma.app/v1.0/generations \
  -H "X-API-KEY: $KEY" -H "Content-Type: application/json" \
  -d '{"inputText":"Quarterly sales report Q4: metrics, wins, 2025 outlook",
       "format":"presentation","textMode":"generate","numCards":10,"exportAs":"pptx"}' \
  | python -c "import sys,json;print(json.load(sys.stdin)['generationId'])")

# poll
curl -s https://public-api.gamma.app/v1.0/generations/$GEN -H "X-API-KEY: $KEY"

Credits (rough, from docs — unverified against a live run)

• text: ~1–3 credits per card (model-dependent)
• images: ~2–15 (standard) up to 30–125 (ultra) credits each
• example: 10-card deck + 5 images ≈ 20–60 credits

Checklist before shipping a Gamma job

• GAMMA_API_KEY valid (auth probe returns 404, not 401)
• format is one of presentation/document/social/webpage
• inputText ≤ 400k chars
• numCards within plan limit (1–75)
• set exportAs only if you need a downloadable file
• poll to completed before using exportUrl (async!)
• grab exportUrl promptly — it expires in ~1 week

Not this skill

• Local slide building / templated decks without Gamma → manus-slides, pptx, slides
• KP / Company decks (HTML→PNG→PPTX) → тот же стек manus-slides + pptx; заточенного под КП навыка в паке нет
• Editing an existing .pptx → pptx

References

• Developer docs: https://developers.gamma.app
• Endpoint spec: https://github.com/gamma-app/gamma-docs