RESTful API Design: Best Practices Guide

RESTful API Design Best Practices

Well-designed APIs are crucial for modern applications. Here's how to create APIs that are intuitive, scalable, and maintainable.

1. Use Proper HTTP Methods

Each HTTP method has a specific purpose:

GET    /users       # List all users
GET    /users/123   # Get specific user
POST   /users       # Create new user
PUT    /users/123   # Update entire user
PATCH  /users/123   # Partial update
DELETE /users/123   # Delete user

2. Resource Naming Conventions

Use nouns, not verbs:

❌ Bad:
GET /getUsers
POST /createUser
DELETE /deleteUser/123

✅ Good:
GET /users
POST /users
DELETE /users/123

3. Proper Status Codes

Return meaningful HTTP status codes:

// Success responses
200 OK              // Successful GET, PUT
201 Created         // Successful POST
204 No Content      // Successful DELETE

// Client errors
400 Bad Request     // Invalid syntax
401 Unauthorized    // Authentication required
403 Forbidden       // No permission
404 Not Found       // Resource doesn't exist

// Server errors
500 Internal Error  // Server fault
503 Service Unavailable

4. Pagination

Always paginate large collections:

GET /users?page=2&limit=20

Response:
{
  "data": [...],
  "pagination": {
    "page": 2,
    "limit": 20,
    "total": 100,
    "pages": 5
  }
}

5. Filtering and Sorting

Support flexible queries:

GET /products?category=electronics&sort=price&order=asc
GET /users?created_after=2025-01-01&status=active

6. API Versioning

Version your API from day one:

# URL versioning
https://api.example.com/v1/users

# Header versioning
GET /users
Accept: application/vnd.api+json;version=1

7. Consistent Response Format

Maintain a predictable structure:

{
  "data": {
    "id": "123",
    "type": "user",
    "attributes": {
      "name": "John Doe",
      "email": "[email protected]"
    }
  },
  "meta": {
    "timestamp": "2025-06-10T10:30:00Z"
  }
}

8. Error Handling

Provide helpful error messages:

{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid input data",
    "details": [
      {
        "field": "email",
        "message": "Email format is invalid"
      }
    ]
  }
}

Conclusion

Good API design is about consistency, predictability, and developer experience. Follow these practices to create APIs that are a joy to work with.