Core Principles

1. Client-Server: Separates client and server responsibilities for modularity.

2. Statelessness: Each request from a client contains all the information necessary, without storing session data server-side.

3. Cacheability: Responses can be cached for better performance.

4. Layered System: Layers operate independently and can be changed without impacting others.

5. Code on Demand (optional): Servers can extend client functionality by delivering code to be executed client-side.

6. Uniform Interface: Consistent interaction across different components.

HTTP Methods

1. GET: Retrieves resources.

2. POST: Creates new resources or submits data.

3. PUT: Updates or replaces existing resources.

4. PATCH: Partially modifies existing resources.

5. DELETE: Deletes resources.

6. HEAD: Similar to GET but only retrieves headers.

7. OPTIONS: Fetches communication options available for a resource.

Status Codes

1. 2xx (Success):

   • 200 OK: The request was successful.

   • 201 Created: The resource was successfully created.

2. 3xx (Redirection):

   • 301 Moved Permanently: The resource was moved to a new URI.

3. 4xx (Client Error):

   • 401 Unauthorized: Authentication is required or has failed.

   • 403 Forbidden: The server understands the request but refuses to authorize it.

   • 404 Not Found: The requested resource could not be found.

4. 5xx (Server Error):

   • 500 Internal Server Error: A generic error occurred on the server side.

Security Best Practices

1. Authentication: Use OAuth 2.0, JWT (JSON Web Tokens).

2. Authorization: Implement RBAC (Role-Based Access Control) or ABAC (Attribute-Based Access Control).

3. HTTPS: Use TLS/SSL for encrypting communications.

4. Input Validation: Always validate and sanitize input data to prevent injection attacks.

5. Rate Limiting and Throttling: Implement limits to avoid abuse.

6. CORS (Cross-Origin Resource Sharing): Control access from different origins.

7. Security Headers: Use headers like Content-Security-Policy and X-Frame-Options for mitigating web vulnerabilities.

Resource Naming Conventions

1. Nouns: Use nouns for resource names (e.g., /users, /products).

2. Pluralization: Use plural nouns for collections (e.g., /users).

3. Hyphens: Use hyphens for readability (e.g., /product-categories).

4. Lowercase: Use lowercase letters consistently.

Best Practices

1. Versioning: Use version numbers in the URI (e.g., /v1/users).

2. Filtering and Sorting: Apply query parameters for filtering and sorting (e.g., /users?status=active&sort=name,asc).

3. Pagination: Use limit and offset parameters for large datasets.

4. Error Handling: Return clear and consistent error codes and messages.

5. Documentation: Use tools like OpenAPI (Swagger) for comprehensive API documentation.

6. Caching: Implement server-side and client-side caching for better performance.