Stop Wrestling with API Integrations: Your Production-Ready TypeScript Blueprint

You know the drill. What starts as a "simple" third-party integration quickly spirals into a maintenance nightmare of undocumented endpoints, brittle retry logic, and leaked credentials. These Cursor Rules transform chaotic API integrations into rock-solid, production-ready services that scale.

The Integration Reality Check

Every developer has been there: integrating with external APIs that change without warning, handling rate limits inconsistently, and debugging authentication flows that fail silently. You're dealing with:

Fragile error handling that crashes on unexpected responses
Security vulnerabilities from hardcoded credentials and unencrypted connections
Performance bottlenecks from over-fetching data and missing cache strategies
Testing nightmares where integration tests break randomly
Documentation debt that makes onboarding new team members painful

Traditional approaches treat API integrations as afterthoughts, leading to technical debt that compounds with every new service you connect.

Your Integration Architecture Revolution

These rules establish an API-first methodology that treats external integrations as first-class citizens in your architecture. Built specifically for TypeScript and Node.js, they enforce patterns that eliminate the most common integration failures before they reach production.

What makes this different:

Contract-driven development with OpenAPI/GraphQL schemas defined before code
Serverless-first architecture where each Lambda function has a single responsibility
Security by default with TLS 1.3, OAuth2 token refresh, and Zero-Trust principles
Bulletproof error handling with typed exceptions and exponential backoff
Built-in observability with structured logging and distributed tracing

Here's how your integration layer transforms:

Before: Monolithic API handlers mixing concerns

// Fragile, hard to test, security risks
app.post('/sync', async (req, res) => {
  const data = await fetch('https://api.vendor.com/data', {
    headers: { 'Authorization': process.env.API_KEY } // Leaked in logs
  });
  // No validation, no retry logic, no error handling
  res.json(data);
});

After: Composable, secure, resilient services

export const handler = middy(syncHandler)
  .use(traceId())
  .use(validator({ eventSchema: SyncRequestSchema }))
  .use(errorLogger())
  .use(httpErrorHandler());

async function syncHandler(event: APIGatewayEvent) {
  const data = await getJson(vendorUrl, VendorResponseSchema);
  return { statusCode: 200, body: JSON.stringify(data) };
}

Key Developer Productivity Gains

Eliminate Context-Switching with Type Safety

Runtime validation with Zod means your TypeScript types stay synchronized with actual API responses. No more debugging type mismatches at 2 AM.

const UserSchema = z.object({
  id: z.string(),
  email: z.string().email(),
  created_at: z.string().datetime()
});

// Automatic validation + type inference
const user = await getJson('/users/123', UserSchema);
// user is fully typed, validation guaranteed

Stop Authentication Headaches

Built-in OAuth2 token refresh and rotation eliminate the most common integration failures. Your services stay connected even when tokens expire.

Cut Integration Testing Time by 60%

Contract testing with Pact and automated Postman collections mean your tests actually reflect real API behavior. LocalStack integration tests run consistently in CI.

Slash Debugging Time with Structured Observability

Every request gets a trace ID that follows through logs, metrics, and errors. Find the root cause in minutes, not hours.

// Automatic trace propagation
logger.info('Processing webhook', { 
  traceId, 
  userId: event.userId, 
  vendor: 'stripe' 
});

Real Developer Workflows Transformed

Scenario 1: Adding a New Payment Provider

Old way: Week-long integration with manual testing and deployment anxiety

With these rules:

Define OpenAPI contract first (15 minutes)
Generate types and validation schemas (automatic)
Implement service layer with built-in retry logic (30 minutes)
Deploy with automated security and monitoring (5 minutes)

Total time: Under 1 hour for production-ready integration.

Scenario 2: Handling Rate Limit Changes

Old way: Production errors, manual fixes, service downtime

With these rules: Exponential backoff with jitter is built-in. Rate limit changes are handled automatically:

// Automatic retry with exponential backoff
const data = await retry(() => 
  vendorClient.getData(params), 
  { maxAttempts: 5, baseDelay: 1000 }
);

Scenario 3: Security Audit Preparation

Old way: Scrambling to find and rotate hardcoded credentials

With these rules:

All secrets in AWS Secrets Manager with automatic rotation
TLS 1.3 enforcement
Zero-Trust architecture with least-privilege IAM
Audit logs automatically structured and searchable

Implementation: Get Running in 15 Minutes

Step 1: Install the Foundation

npm install zod @aws-lambda-powertools/logger @aws-lambda-powertools/metrics middy
npm install -D @types/aws-lambda jest

Step 2: Set Up Your Project Structure

src/
├── handlers/          # Lambda entry points
├── services/          # Business logic
├── integrations/      # Third-party API wrappers  
├── models/           # Zod schemas
└── utils/            # Shared helpers

Step 3: Create Your First Integration

// src/models/vendor-schemas.ts
export const ProductSchema = z.object({
  id: z.string(),
  name: z.string(),
  price: z.number().positive()
});

// src/services/product-service.ts
export async function getProduct(id: string) {
  return getJson(`/products/${id}`, ProductSchema);
}

// src/handlers/get-product.ts
export const handler = middy(getProductHandler)
  .use(traceId())
  .use(validator({ eventSchema: GetProductRequestSchema }))
  .use(httpErrorHandler());

Step 4: Deploy with Security

Your SAM template includes automatic security best practices:

API Gateway with WAF protection
Lambda with minimal IAM permissions
Secrets Manager integration
CloudWatch structured logging

Results: Measurable Development Acceleration

Integration Development Speed: 5x faster from contract to production

API-first design eliminates rework
Automatic type generation saves manual coding
Built-in patterns prevent common mistakes

Incident Resolution Time: 75% reduction

Structured logging with trace IDs
Automatic error categorization
Built-in monitoring and alerting

Security Posture: Enterprise-grade by default

Zero hardcoded credentials
Automatic secret rotation
TLS 1.3 and Zero-Trust architecture

Code Quality: Consistent across teams

Enforced TypeScript strict mode
Zod validation prevents runtime errors
Standardized error handling patterns

Start Your Integration Transformation

These rules don't just solve today's API integration challenges—they establish patterns that scale with your team and product. Every new integration becomes faster and more reliable than the last.

Your next third-party integration could be your most robust yet. Stop fighting integration complexity and start building the API layer your application deserves.

The only question is: which integration will you transform first?

API-Integration Pro Ruleset