---

name: retellai-sdk-patterns description: | Apply production-ready Retell AI SDK patterns for TypeScript and Python. Use when implementing Retell AI integrations, refactoring SDK usage, or establishing team coding standards for Retell AI. Trigger with phrases like "retellai SDK patterns", "retellai best practices", "retellai code patterns", "idiomatic retellai". allowed-tools: Read, Write, Edit version: 1.0.0 license: MIT author: Jeremy Longshore jeremy@intentsolutions.io

Retell AI SDK Patterns

Overview

Production-ready patterns for Retell AI SDK usage in TypeScript and Python.

Prerequisites

• Completed retellai-install-auth setup
• Familiarity with async/await patterns
• Understanding of error handling best practices

Instructions

Step 1: Implement Singleton Pattern (Recommended)

Copy// src/retellai/client.ts
import { RetellAIClient } from '@retellai/sdk';

let instance: RetellAIClient | null = null;

export function getRetell AIClient(): RetellAIClient {
  if (!instance) {
    instance = new RetellAIClient({
      apiKey: process.env.RETELLAI_API_KEY!,
      // Additional options
    });
  }
  return instance;
}

Step 2: Add Error Handling Wrapper

Copyimport { Retell AIError } from '@retellai/sdk';

async function safeRetell AICall<T>(
  operation: () => Promise<T>
): Promise<{ data: T | null; error: Error | null }> {
  try {
    const data = await operation();
    return { data, error: null };
  } catch (err) {
    if (err instanceof Retell AIError) {
      console.error({
        code: err.code,
        message: err.message,
      });
    }
    return { data: null, error: err as Error };
  }
}

Step 3: Implement Retry Logic

Copyasync function withRetry<T>(
  operation: () => Promise<T>,
  maxRetries = 3,
  backoffMs = 1000
): Promise<T> {
  for (let attempt = 1; attempt <= maxRetries; attempt++) {
    try {
      return await operation();
    } catch (err) {
      if (attempt === maxRetries) throw err;
      const delay = backoffMs * Math.pow(2, attempt - 1);
      await new Promise(r => setTimeout(r, delay));
    }
  }
  throw new Error('Unreachable');
}

Output

• Type-safe client singleton
• Robust error handling with structured logging
• Automatic retry with exponential backoff
• Runtime validation for API responses

Error Handling

Examples

Factory Pattern (Multi-tenant)

Copyconst clients = new Map<string, RetellAIClient>();

export function getClientForTenant(tenantId: string): RetellAIClient {
  if (!clients.has(tenantId)) {
    const apiKey = getTenantApiKey(tenantId);
    clients.set(tenantId, new RetellAIClient({ apiKey }));
  }
  return clients.get(tenantId)!;
}

Python Context Manager

Copyfrom contextlib import asynccontextmanager
from retellai import RetellAIClient

@asynccontextmanager
async def get_retellai_client():
    client = RetellAIClient()
    try:
        yield client
    finally:
        await client.close()

Zod Validation

Copyimport { z } from 'zod';

const retellaiResponseSchema = z.object({
  id: z.string(),
  status: z.enum(['active', 'inactive']),
  createdAt: z.string().datetime(),
});

Resources

• Retell AI SDK Reference
• Retell AI API Types
• Zod Documentation

Next Steps

Apply patterns in retellai-core-workflow-a for real-world usage.