REST API Design Best Practices
A well-designed API is a joy to work with. A poorly designed one causes endless frustration. Here's how to design APIs that developers love.
Core Principles
- Consistency: Same patterns everywhere
- Predictability: Behave as expected
- Simplicity: Easy to understand and use
- Documentation: Clear, complete docs
URL Structure
Use nouns, not verbs: - Good: GET /users/123 - Bad: GET /getUser?id=123
Use plural nouns: - Good: /users, /orders - Bad: /user, /order
Nest for relationships: - GET /users/123/orders
HTTP Methods
- GET: Retrieve resources
- POST: Create resources
- PUT: Replace resources
- PATCH: Partial updates
- DELETE: Remove resources
Response Codes
Use appropriate status codes: - 200: Success - 201: Created - 400: Bad request - 401: Unauthorized - 404: Not found - 500: Server error
Pagination
For list endpoints: - Use cursor-based pagination for large datasets - Include total count and next/previous links - Allow configurable page sizes
Error Handling
Return consistent error responses: - Error code - Human-readable message - Field-level errors for validation - Request ID for debugging
Versioning
Version your API from day one: - URL versioning: /v1/users - Header versioning: Accept: application/vnd.api+json;version=1
Security
- Always use HTTPS
- Implement authentication (JWT, OAuth)
- Rate limiting
- Input validation
- CORS configuration
Good API design is an investment that pays dividends. At HostSpica, we design APIs that scale and evolve gracefully.