Replit SDK Patterns

Overview

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

Prerequisites

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

Instructions

Step 1: Implement Singleton Pattern (Recommended)

// src/replit/client.ts
import { ReplitClient } from '@replit/sdk';

let instance: ReplitClient | null = null;

export function getReplitClient(): ReplitClient {
  if (!instance) {
    instance = new ReplitClient({
      apiKey: process.env.REPLIT_API_KEY!,
      // Additional options
    });
  }
  return instance;
}

Step 2: Add Error Handling Wrapper

import { ReplitError } from '@replit/sdk';

async function safeReplitCall<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 ReplitError) {
      console.error({
        code: err.code,
        message: err.message,
      });
    }
    return { data: null, error: err as Error };
  }
}

Step 3: Implement Retry Logic

async function withRetry<T>(
  operation: () => Promise<T>,
  maxRetries = 3,
  backoffMs = 1000  # 1000: 1 second in ms
): 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

Pattern	Use Case	Benefit
Safe wrapper	All API calls	Prevents uncaught exceptions
Retry logic	Transient failures	Improves reliability
Type guards	Response validation	Catches API changes
Logging	All operations	Debugging and monitoring

Examples

Factory Pattern (Multi-tenant)

const clients = new Map<string, ReplitClient>();

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

Python Context Manager

from contextlib import asynccontextmanager
from replit import ReplitClient

@asynccontextmanager
async def get_replit_client():
    client = ReplitClient()
    try:
        yield client
    finally:
        await client.close()

Zod Validation

import { z } from 'zod';

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

Resources

• Replit SDK Reference
• Replit API Types
• Zod Documentation

Next Steps

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