API Design Best Practices for Modern Applications

APIs are Products

A well-designed API is a joy to use. A poorly designed one frustrates users and creates technical debt. Design with care.

RESTful Principles

Use HTTP methods correctly: GET for reading, POST for creating, PUT/PATCH for updating, DELETE for removing. Use proper status codes.

Consistent Naming

Use clear, consistent naming conventions. Plural nouns for collections (/users), not verbs (/getUsers). Use kebab-case or snake_case consistently.

Versioning

Version your API from day one. Use URL versioning (/v1/users) or header versioning. Make breaking changes in new versions only.

Error Handling

Return meaningful error messages with proper status codes. Include error codes, messages, and suggested solutions when possible.

Pagination

Always paginate list endpoints. Support cursor-based pagination for large datasets. Return metadata about total count and available pages.

Filtering and Sorting

Allow clients to filter and sort results. Use query parameters: /users?role=admin&sort=created_at:desc.

Authentication and Authorization

Use OAuth 2.0 or JWT for authentication. Implement proper authorization checks. Never trust client input.

Rate Limiting

Protect your API with rate limiting. Return clear headers indicating limits and remaining quota.

Documentation

Comprehensive documentation is crucial. Use tools like Swagger/OpenAPI. Include examples for every endpoint.

Monitoring

Track API usage, errors, and performance. Monitor for unusual patterns. Use this data to improve your API.