APIs (Application Programming Interfaces) connect your business website to external services — payment gateways, CRM systems, shipping providers, communication platforms, and more. Understanding REST, GraphQL, and webhooks helps you choose the right integration approach for each use case, reducing development time and improving reliability.
What Are the Main Types of APIs Used in Business Websites?
| API Type | How It Works | Best For | Example |
|---|---|---|---|
| REST | Request-response over HTTP using standard methods (GET, POST, PUT, DELETE) | Most integrations; simple, widely supported | Razorpay payment API, Google Maps API |
| GraphQL | Single endpoint; client specifies exactly what data it needs | Complex data fetching, mobile apps, SPAs | Shopify Storefront API, GitHub API v4 |
| Webhooks | Server pushes data to your endpoint when an event occurs | Real-time notifications, event-driven workflows | Payment confirmation, form submission, order status |
| SOAP | XML-based protocol with strict contracts | Legacy enterprise systems, banking | Some Indian banking and government APIs |
How Do REST APIs Work?
REST (Representational State Transfer) is the most common API architecture for web integrations. It uses standard HTTP methods:
- GET — retrieve data (e.g., fetch product details, list orders)
- POST — create data (e.g., create a new order, submit a form)
- PUT/PATCH — update data (e.g., update customer profile, modify an order)
- DELETE — remove data (e.g., cancel a subscription)
REST APIs return data typically as JSON, are stateless (each request is independent), and use URLs to identify resources. Most Indian payment gateways (Razorpay, Cashfree, PayU), communication APIs (MSG91, Twilio), and logistics APIs (Shiprocket, Delhivery) use REST.
When Should You Use GraphQL Instead of REST?
GraphQL solves specific problems that REST handles less efficiently:
- Over-fetching: REST endpoints often return more data than you need. GraphQL lets you request only the fields you want
- Under-fetching: Getting related data in REST may require multiple API calls. GraphQL can fetch nested related data in one request
- Rapid front-end development: Front-end developers can change data requirements without backend changes
Use GraphQL when building data-rich single-page applications, mobile apps with bandwidth constraints, or when consuming APIs that offer it (Shopify, WooCommerce via WPGraphQL). Stick with REST for simpler integrations and when the service only offers REST endpoints.
How Do Webhooks Fit In?
Webhooks are reverse APIs — instead of your server asking for data, the external service sends data to your server when something happens:
- Payment confirmed: Razorpay sends a webhook to your server when a payment succeeds or fails
- Order shipped: Shiprocket notifies your site when the tracking status changes
- Form submitted: Typeform or Gravity Forms can push submissions to your CRM
- Subscription renewed: WooCommerce Subscriptions fires webhooks on renewal events
Webhooks are essential for real-time synchronisation and event-driven architectures. They eliminate the need for polling (repeatedly checking for updates), which wastes server resources.
What Are API Authentication Methods?
| Method | Security Level | Use Case |
|---|---|---|
| API Key | Basic | Simple integrations, server-to-server calls |
| OAuth 2.0 | High | User-authorised access to third-party data (Google, Facebook APIs) |
| JWT (JSON Web Tokens) | Good | Stateless authentication for SPAs and mobile apps |
| HMAC Signature | High | Webhook verification (Razorpay, Stripe use this) |
| Basic Auth | Low | Legacy systems, internal APIs only (always over HTTPS) |
What Are the Best Practices for API Integration?
- Never expose API keys in front-end code. Make API calls from your server, not from JavaScript in the browser
- Implement proper error handling. APIs fail — handle timeouts, rate limits, 4xx and 5xx responses gracefully. Show users helpful messages, not raw error codes
- Use environment variables for API keys and secrets. Never commit them to version control
- Validate webhook payloads. Verify the HMAC signature to confirm the webhook came from the expected service
- Implement retry logic with exponential backoff for failed requests
- Log API calls and responses for debugging and auditing, but redact sensitive data in logs
- Respect rate limits. Most APIs limit requests per minute or hour. Implement caching and queuing to stay within limits
- Use SDKs when available. Razorpay, Cashfree, and other Indian services provide PHP, Node.js, and Python SDKs that handle authentication and error cases for you
What APIs Do Indian Business Websites Commonly Need?
- Payments: Razorpay, Cashfree, PayU, Stripe, PayPal
- SMS/WhatsApp: MSG91, Twilio, Gupshup
- Email: SendGrid, Mailgun, Amazon SES
- Shipping: Shiprocket, Delhivery, Ecom Express
- Maps and location: Google Maps, Mapbox
- GST: ClearTax, Zoho GST APIs for invoice compliance
- CRM: HubSpot, Zoho CRM, Salesforce
- Analytics: Google Analytics Data API, Facebook Marketing API
FAQ: Should I build API integrations myself or use plugins/Zapier?
For standard integrations (payment gateways, email services), use established plugins or SDKs — they are tested, maintained, and handle edge cases. For custom workflows (syncing orders to a proprietary ERP, custom CRM flows), either build custom integrations or use middleware like Zapier, Make (Integromat), or Pabbly Connect. Middleware is faster to set up but adds a recurring cost and a dependency.
FAQ: How do I test API integrations safely?
Most Indian payment gateways and service APIs offer sandbox or test environments. Razorpay, Cashfree, and Stripe all provide test API keys that simulate transactions without real money. Always develop and test against sandbox environments before switching to production keys. Use tools like Postman or Insomnia to test API calls independently before integrating them into your code.
FAQ: What happens when a third-party API goes down?
Design for failure. Implement circuit breakers that stop calling a failing API after repeated failures. Use fallback mechanisms where possible (e.g., queue orders for processing when the shipping API is down). Display user-friendly messages instead of errors. Monitor API health and set up alerts for failures. For critical services, consider having a backup provider.
