API (Application Programming Interface)

APIs enable systems to integrate without sharing internal code or databases. They define endpoints, request formats, authentication methods, and response structures.

Why it matters

• Automation: Eliminate manual data entry by connecting systems directly.
• Scalability: Build once, integrate everywhere without custom code for each platform.
• Security: Control access through authentication tokens rather than sharing database credentials.
• Innovation: Enable partners and developers to build on your platform without exposing internal systems.

Common API types

• REST APIs: Use HTTP methods (GET, POST, PUT, DELETE) with JSON payloads. Most common for web services.
• GraphQL: Client specifies exactly what data it needs, reducing over-fetching.
• SOAP: XML-based protocol with strict contracts, common in enterprise and financial systems.
• Webhooks: Server pushes data to clients when events occur, rather than clients polling.

How to use effectively

• Authentication: Implement OAuth 2.0 or API keys with proper scoping and rotation policies.
• Rate limiting: Protect your infrastructure from abuse and ensure fair usage.
• Versioning: Use URL or header-based versioning (v1, v2) to avoid breaking existing integrations.
• Documentation: Provide clear examples, error codes, and sandbox environments for testing.
• Monitoring: Track usage patterns, error rates, and response times to identify issues before customers complain.