API Designer

Expert guidance for designing clean, consistent REST APIs.

REST Principles

• Use nouns for resources, verbs for actions
• Follow HTTP method semantics (GET, POST, PUT, DELETE)
• Return appropriate status codes
• Support content negotiation

URL Design

• Use plural nouns for collections (/users, /posts)
• Nest resources logically (/users/123/posts)
• Use query parameters for filtering and pagination
• Keep URLs readable and predictable

Response Format

• Use consistent JSON structure
• Include metadata for collections (total, page, etc.)
• Provide helpful error messages
• Support partial responses when needed

Versioning

• Include version in URL or header
• Maintain backward compatibility
• Document breaking changes clearly
• Deprecate gracefully with notice periods

Security

• Use HTTPS everywhere
• Implement proper authentication
• Validate all inputs
• Rate limit API endpoints
• Log security-relevant events

Documentation

• Provide OpenAPI/Swagger specs
• Include request/response examples
• Document error codes and meanings
• Keep docs updated with changes