gamma-core-workflow-b

Gamma Core Workflow B: Templates & Export

Overview

Use Gamma's template-based generation (POST /v1.0/generations/from-template) and export retrieval (GET /v1.0/generations/{id}/files) endpoints. Template generation lets you replicate a single-page gamma template across multiple variations. Export retrieval gives you downloadable PDF, PPTX, and PNG files.

Prerequisites

• Completed gamma-core-workflow-a
• A template gamma with exactly one page (created in the Gamma app)
• Understanding of the generate-poll-retrieve pattern

Key Concepts

• Template gamma: A regular gamma with exactly one page, used as a repeatable template
• gammaId: Found in the gamma URL or copied from the app
• Export URLs: Temporary download links returned after generation — download promptly as they expire

Instructions

Step 1: Create from Template

import { createGammaClient, pollUntilDone } from "./lib/gamma";

const gamma = createGammaClient({ apiKey: process.env.GAMMA_API_KEY! });

// POST /v1.0/generations/from-template
// The template gamma MUST have exactly one page
async function generateFromTemplate(
  templateGammaId: string,
  prompt: string,
  options: {
    themeId?: string;
    exportAs?: "pdf" | "pptx" | "png";
    imageStyle?: string;
  } = {}
) {
  const { generationId } = await gamma.generateFromTemplate({
    gammaId: templateGammaId,
    prompt,
    themeId: options.themeId,
    exportAs: options.exportAs,
    imageOptions: options.imageStyle
      ? { style: options.imageStyle }
      : undefined,
  });

  return pollUntilDone(gamma, generationId);
}

// Usage: generate a sales proposal from a template
const result = await generateFromTemplate(
  "gamma_template_abc123",   // Your one-page template ID
  "Create a sales proposal for Acme Corp. Highlight our cloud migration services, 99.9% uptime SLA, and 24/7 support.",
  { exportAs: "pdf", imageStyle: "corporate professional" }
);

console.log(`View: ${result.gammaUrl}`);
console.log(`Download: ${result.exportUrl}`);

Step 2: Batch Template Generation

// Generate multiple variations from the same template
const clients = [
  { name: "Acme Corp", focus: "cloud migration" },
  { name: "TechStart Inc", focus: "AI implementation" },
  { name: "GlobalBank", focus: "security compliance" },
];

import pLimit from "p-limit";
const limit = pLimit(2); // Respect rate limits

const proposals = await Promise.allSettled(
  clients.map((client) =>
    limit(() =>
      generateFromTemplate(
        "gamma_template_abc123",
        `Proposal for ${client.name} focusing on ${client.focus}. Include pricing tier for enterprise. Reference their industry.`,
        { exportAs: "pptx" }
      )
    )
  )
);

proposals.forEach((r, i) => {
  const status = r.status === "fulfilled" ? r.value.gammaUrl : `FAILED: ${r.reason}`;
  console.log(`${clients[i].name}: ${status}`);
});

Step 3: Export Format Selection

// Export is specified at generation time via `exportAs`
// You cannot export an already-generated gamma via the API
// Instead, generate with the desired export format

// PDF export — best for sharing externally
const pdfResult = await gamma.generate({
  content: "Annual report for 2025",
  outputFormat: "document",
  exportAs: "pdf",
});

// PPTX export — for editing in PowerPoint/Google Slides
// Note: PPTX exports may have layout shifts and font differences
const pptxResult = await gamma.generate({
  content: "Team kickoff presentation",
  outputFormat: "presentation",
  exportAs: "pptx",
});

// PNG export — for thumbnails or social sharing
const pngResult = await gamma.generate({
  content: "Product announcement graphic",
  outputFormat: "social_post",
  exportAs: "png",
});

Step 4: Retrieve Export Files

// After generation completes, exportUrl is in the poll response
// Download files promptly — URLs expire after a period

import { writeFile } from "node:fs/promises";

async function downloadExport(generationId: string, outputPath: string) {
  // Poll until complete
  const result = await pollUntilDone(gamma, generationId);

  if (!result.exportUrl) {
    throw new Error("No export URL — did you specify exportAs?");
  }

  // Download the file
  const response = await fetch(result.exportUrl);
  if (!response.ok) throw new Error(`Download failed: ${response.status}`);

  const buffer = Buffer.from(await response.arrayBuffer());
  await writeFile(outputPath, buffer);
  console.log(`Saved to ${outputPath} (${buffer.length} bytes)`);
}

// Usage
const { generationId } = await gamma.generate({
  content: "Sales deck for Q1 review",
  outputFormat: "presentation",
  exportAs: "pdf",
});

await downloadExport(generationId, "./output/q1-review.pdf");

Step 5: Sharing Configuration

// Configure who can access the generated gamma
const { generationId } = await gamma.generate({
  content: "Internal strategy document",
  outputFormat: "document",
  sharingOptions: {
    // Workspace members
    workspaceAccess: "comment",  // noAccess | view | comment | edit | fullAccess

    // External (non-workspace) visitors
    externalAccess: "noAccess",  // Lock down for internal docs

    // Share with specific people via email
    emailOptions: {
      emails: ["partner@example.com"],
      accessLevel: "view",
    },
  },
});

Step 6: curl Reference

# Generate from template
curl -X POST "https://public-api.gamma.app/v1.0/generations/from-template" \
  -H "X-API-KEY: ${GAMMA_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "gammaId": "your_template_gamma_id",
    "prompt": "Create a proposal for Acme Corp focusing on cloud services",
    "exportAs": "pdf",
    "themeId": "theme_abc123",
    "imageOptions": { "style": "photorealistic" },
    "sharingOptions": {
      "workspaceAccess": "edit",
      "externalAccess": "view"
    }
  }'

# Poll for result
curl "https://public-api.gamma.app/v1.0/generations/${GEN_ID}" \
  -H "X-API-KEY: ${GAMMA_API_KEY}" | jq '{status, gammaUrl, exportUrl, creditsUsed}'

Export Format Comparison

Format	Best For	Fidelity	Editable?
PDF	Sharing, printing	High	No
PPTX	Editing in PowerPoint/Slides	Medium (layout shifts possible)	Yes
PNG	Thumbnails, social media	High (single image)	No

Error Handling

Error	Cause	Solution
"Template must have exactly one page"	Multi-page template	Edit template to single page
Empty exportUrl	exportAs not specified	Add exportAs to generation request
Download URL expired	Too slow to download	Download immediately after completion
422 on template generation	Invalid gammaId	Verify template ID from Gamma app URL

Resources

• Create from Template
• Template Parameters Explained
• Receive Generated File URLs

Next Steps

Proceed to gamma-common-errors for troubleshooting API issues.