API Endpoint Domain: Setup and Best Practices

Running an API on a dedicated subdomain like api.is-pro.dev is a common pattern for modern web applications. It keeps your API separate from your frontend, simplifies CORS configuration, and allows independent scaling. This guide covers everything you need to set up and secure your API endpoint with a free is-pro.dev subdomain.

Why Use a Dedicated API Domain

Separating your API onto its own subdomain offers several advantages:

Clean separation of concerns between your frontend and backend
Simplified CORS configuration since the frontend domain differs from the API domain
Independent scaling — your API can be hosted on different infrastructure from your frontend
Professional URL structure like api.project.is-pro.dev

Choosing Your API Subdomain

Common naming patterns for API subdomains:

api.is-pro.dev for a general API
api.your-project.is-pro.dev for project-specific APIs
graphql.is-pro.dev for GraphQL endpoints
v1.api.is-pro.dev for versioned APIs

DNS Configuration for APIs

For API servers, you typically need an A record pointing to your server's IP address:


Type: A
Name: api
IPv4: your-server-ip
Proxy Status: DNS only (gray cloud) for TCP-based APIs, Proxied (orange cloud) for HTTP APIs


If your API is hosted on a platform like Railway, Render, or Fly.io, use a CNAME record instead pointing to the platform's provided domain.
SSL for API Endpoints
HTTPS is essential for APIs to protect data in transit. Configuration options:
Cloudflare Proxy (orange cloud): SSL is handled automatically by Cloudflare. Your API is served over HTTPS with Cloudflare's shared certificate. This works well for REST and GraphQL APIs over HTTP/HTTPS.
Let's Encrypt: For direct SSL termination on your server, use Certbot:

`bash


sudo certbot --nginx -d api.is-pro.dev


Caddy: Automatically provisions and renews SSL certificates:


api.is-pro.dev {
    reverse_proxy localhost:3000
}


CORS Configuration
When your frontend is on a different domain than your API, configure CORS headers:
Node.js (Express):

`javascript


const cors = require('cors');
app.use(cors({
    origin: ['https://app.is-pro.dev', 'https://your-frontend.vercel.app'],
    methods: ['GET', 'POST', 'PUT', 'DELETE'],
    credentials: true
}));


Python (FastAPI):

`python


from fastapi.middleware.cors import CORSMiddleware
app.add_middleware(CORSMiddleware,
    allow_origins=["https://app.is-pro.dev"],
    allow_methods=["*"],
    allow_headers=["*"])


Go (Gin):

`go


r.Use(cors.New(cors.Config{
    AllowOrigins: []string{"https://app.is-pro.dev"},
    AllowMethods: []string{"GET", "POST", "PUT", "DELETE"},
}))


Rate Limiting
Protect your API from abuse with rate limiting:
Cloudflare Rate Limiting: Configure in the Cloudflare dashboard under Security → WAF → Rate Limiting. Free plan allows 10 rules. Set thresholds based on your API's expected usage patterns.
Application-level limiting: Use middleware in your framework:

`javascript


const rateLimit = require('express-rate-limit');
const limiter = rateLimit({
    windowMs: 15  60  1000,
    max: 100,
    message: { error: 'Too many requests' }
});
app.use('/api/', limiter);


API Documentation
Make your API discoverable with documentation:
OpenAPI/Swagger: Define your API schema in OpenAPI 3.0 format. Host the documentation on a subpath of your API domain:


https://api.is-pro.dev/docs


Postman: Create a public workspace with collection and environment templates. Link to it from your API's root endpoint.
Response headers: Include API version, rate limit status, and documentation links in response headers.
Monitoring and Logging
Set up basic monitoring for your API:

Health check endpoint at /health returning status and uptime


Structured logging with correlation IDs for request tracking
Uptime monitoring with services like UptimeRobot (free tier: 50 monitors)
Error tracking with Sentry (free tier available)


Troubleshooting

CORS errors: Verify that your CORS configuration includes the exact origin of your frontend (including protocol and port if applicable). Use curl -H "Origin: https://app.is-pro.dev" -I https://api.is-pro.dev/endpoint to test.


SSL handshake failures for proxied APIs: If using Cloudflare proxy (orange cloud), ensure your origin server accepts connections from Cloudflare's IP ranges. These are published in Cloudflare's documentation.
Rate limiting too aggressive: Monitor your API usage patterns before setting limits. Start with generous limits and tighten based on observed traffic.
FAQ
Q: Can I use WebSockets with a proxied Cloudflare domain?
A: Yes, Cloudflare supports WebSocket connections through proxied DNS. Ensure your server supports WebSocket upgrades.
Q: How do I version my API?

A: Include the version in the URL path (/v1/users) or use a separate subdomain (v1.api.is-pro.dev`). Path-based versioning is simpler to configure.

Q: Can I use HTTP/2 for my API?

A: Yes, Cloudflare supports HTTP/2 automatically for proxied domains. Enable it in the Speed settings.

Conclusion

Setting up an API endpoint on a dedicated is-pro.dev subdomain gives you a professional, scalable architecture at zero cost. Configure DNS, enable SSL, set up CORS, implement rate limiting, and document your endpoints. Your API will be production-ready and accessible worldwide.

Written by Mayank Baswal

API Endpoint Domain: Setup and Best Practices

Why Use a Dedicated API Domain

Choosing Your API Subdomain

DNS Configuration for APIs

SSL for API Endpoints

CORS Configuration

Rate Limiting

API Documentation

Monitoring and Logging

Troubleshooting

FAQ

Conclusion