Gamma SDK Patterns

Overview

Learn idiomatic patterns and best practices for the Gamma SDK to build robust presentation automation.

Prerequisites

• Completed gamma-local-dev-loop setup
• Familiarity with async/await patterns
• TypeScript recommended

Instructions

Pattern 1: Client Singleton

// lib/gamma.ts
import { GammaClient } from '@gamma/sdk';

let client: GammaClient | null = null;

export function getGammaClient(): GammaClient {
  if (!client) {
    client = new GammaClient({
      apiKey: process.env.GAMMA_API_KEY,
      timeout: 30000,
      retries: 3,
    });
  }
  return client;
}

Pattern 2: Presentation Builder

// lib/presentation-builder.ts
import { getGammaClient } from './gamma';

interface SlideContent {
  title: string;
  content: string;
  layout?: 'title' | 'content' | 'image' | 'split';
}

export class PresentationBuilder {
  private slides: SlideContent[] = [];
  private title: string = '';
  private style: string = 'professional';

  setTitle(title: string): this {
    this.title = title;
    return this;
  }

  addSlide(slide: SlideContent): this {
    this.slides.push(slide);
    return this;
  }

  setStyle(style: string): this {
    this.style = style;
    return this;
  }

  async build() {
    const gamma = getGammaClient();
    return gamma.presentations.create({
      title: this.title,
      slides: this.slides,
      style: this.style,
    });
  }
}

Pattern 3: Error Handling Wrapper

// lib/safe-gamma.ts
import { GammaError } from '@gamma/sdk';

export async function safeGammaCall<T>(
  fn: () => Promise<T>
): Promise<{ data: T; error: null } | { data: null; error: string }> {
  try {
    const data = await fn();
    return { data, error: null };
  } catch (err) {
    if (err instanceof GammaError) {
      return { data: null, error: err.message };
    }
    throw err;
  }
}

Pattern 4: Template Factory

// lib/templates.ts
type TemplateType = 'pitch-deck' | 'report' | 'tutorial' | 'proposal';

const TEMPLATES: Record<TemplateType, object> = {
  'pitch-deck': { slides: 10, style: 'bold' },
  'report': { slides: 15, style: 'professional' },
  'tutorial': { slides: 8, style: 'friendly' },
  'proposal': { slides: 12, style: 'corporate' },
};

export function fromTemplate(type: TemplateType, title: string) {
  return { ...TEMPLATES[type], title };
}

Output

• Reusable client singleton
• Fluent builder pattern
• Type-safe error handling
• Template factory system

Error Handling

Pattern	Use Case	Benefit
Singleton	Multiple modules	Consistent config
Builder	Complex presentations	Readable code
Safe Call	Error boundaries	Graceful failures
Factory	Repeated templates	DRY code

Resources

• Gamma SDK Patterns
• TypeScript Design Patterns

Next Steps

Proceed to gamma-core-workflow-a for presentation generation workflows.