API Design Checklist
API Design Checklist
Comprehensive checklist for designing robust, scalable APIs
Follow RESTful principles
Use proper HTTP methods, status codes, and resource-based URLs
Examples:
- •
GET /users/123 (retrieve user) - •
POST /users (create user) - •
PUT /users/123 (update user) - •
DELETE /users/123 (delete user)
Use consistent naming conventions
Maintain consistent resource naming, casing, and URL structure
Examples:
- •
Use plural nouns: /users, /orders, /products - •
Use kebab-case: /user-profiles, /order-items - •
Avoid verbs in URLs: /users not /getUsers
Implement API versioning
Plan for API evolution with proper versioning strategy
Examples:
- •
URL versioning: /v1/users, /v2/users - •
Header versioning: Accept: application/vnd.api+json;version=1 - •
Query parameter: /users?version=1
Validate all input data
Implement comprehensive input validation and sanitization
Examples:
- •
Required field validation - •
Data type validation - •
Format validation (email, phone) - •
Range and length validation
Standardize response format
Use consistent response structure across all endpoints
Examples:
- •
{ "data": {...}, "meta": {...}, "errors": [...] } - •
Include pagination metadata - •
Consistent error response format
Use appropriate HTTP status codes
Return meaningful status codes for different scenarios
Examples:
- •
200 OK - Successful GET, PUT - •
201 Created - Successful POST - •
400 Bad Request - Invalid input - •
401 Unauthorized - Authentication required - •
404 Not Found - Resource not found - •
500 Internal Server Error - Server error
Implement proper authentication
Secure API endpoints with appropriate authentication mechanisms
Examples:
- •
JWT tokens for stateless authentication - •
OAuth 2.0 for third-party access - •
API keys for service-to-service - •
Multi-factor authentication for sensitive operations
Implement role-based access control
Control access to resources based on user roles and permissions
Examples:
- •
Role-based permissions (admin, user, guest) - •
Resource-level access control - •
Scope-based authorization - •
Principle of least privilege
Enforce HTTPS everywhere
Use TLS encryption for all API communications
Examples:
- •
Redirect HTTP to HTTPS - •
Use HSTS headers - •
Validate SSL certificates - •
Use strong cipher suites
Implement rate limiting
Protect against abuse with request rate limiting
Examples:
- •
Per-user rate limits - •
Per-IP rate limits - •
Different limits for different endpoints - •
Graceful degradation when limits exceeded
Implement caching strategy
Use appropriate caching mechanisms to improve performance
Examples:
- •
HTTP caching headers (Cache-Control, ETag) - •
CDN for static content - •
Application-level caching - •
Database query caching
Implement pagination for large datasets
Prevent performance issues with large response payloads
Examples:
- •
Cursor-based pagination for real-time data - •
Offset-based pagination for static data - •
Include pagination metadata - •
Configurable page sizes with limits
Enable response compression
Reduce bandwidth usage with response compression
Examples:
- •
Gzip compression for text responses - •
Brotli compression for modern browsers - •
Compress responses > 1KB - •
Set appropriate compression levels
Provide comprehensive API documentation
Create clear, up-to-date documentation for all endpoints
Examples:
- •
OpenAPI/Swagger specifications - •
Interactive API explorer - •
Code examples in multiple languages - •
Authentication examples
Document all error responses
Provide clear error codes and resolution steps
Examples:
- •
Error code reference - •
Error message formats - •
Troubleshooting guides - •
Common error scenarios
Implement comprehensive logging
Log requests, responses, and errors for debugging and monitoring
Examples:
- •
Request/response logging - •
Error logging with stack traces - •
Performance metrics logging - •
Security event logging
Provide health check endpoints
Enable monitoring and load balancer health checks
Examples:
- •
/health - Basic health check - •
/health/detailed - Dependency checks - •
/metrics - Performance metrics - •
/status - Service status
Implement comprehensive testing
Test all API endpoints thoroughly
Examples:
- •
Unit tests for business logic - •
Integration tests for endpoints - •
Contract tests for API compatibility - •
Load tests for performance
Checklist Summary
Pro Tip: Focus on completing all Critical and High priority items first. These form the foundation of a well-designed API and are essential for security, performance, and maintainability.