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

Error Handling

Resources

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

Next Steps

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