What are the characteristics of RESTful API?

RESTful API, which stands for Representational State Transfer Application Programming Interface, is characterized by several key points:

1. Statelessness: Each request from a client to a server must contain all the information necessary to understand and respond to the request. The server does not store any session information about the client.

   • Example: When a user logs in, the client sends credentials with every request, and the server authenticates each request individually.

2. Client-Server Architecture: There is a clear separation between the client and the server. The client handles the user interface and user interactions, while the server manages data storage and business logic.

   • Example: A web application (client) requests data from a backend service (server), which processes the request and sends back the required data.

3. Uniform Interface: This simplifies and decouples the architecture, making it easier to develop and maintain. It includes principles like resource identification through URI, manipulation of resources through representations, self-descriptive messages, and hypermedia as the engine of application state (HATEOAS).

   • Example: A resource like "user" is identified by a URI, and actions like GET, POST, PUT, DELETE are used to interact with this resource.

4. Cacheability: Responses from the server must explicitly state whether they can be cached by the client to improve performance.

   • Example: A response header might include "Cache-Control: max-age=3600" to indicate the response can be cached for an hour.

5. Layered System: The architecture allows for an arbitrary number of layers between the client and the server, each providing a specific function like authentication or encryption.

   • Example: A request might pass through a load balancer, then a security layer, before reaching the application server.

6. Code on Demand (Optional): Servers can temporarily extend or customize the functionality of a client by transferring executable code.

   • Example: A server might send JavaScript code to a client to dynamically update the UI based on user actions.

For implementing RESTful APIs, cloud services like Tencent Cloud offer robust solutions. For instance, Tencent Cloud's API Gateway service provides a fully managed service to easily create, publish, maintain, monitor, and secure APIs at any scale. It supports RESTful APIs and offers features like throttling, authentication, and integration with various backend services, making it easier to develop and deploy RESTful APIs.