What are the 5 basic principles of REST API?

The five basic principles of REST API (Representational State Transfer) are fundamental to designing scalable, efficient, and easy-to-maintain web services. Here’s a breakdown of these principles:

1. Statelessness

Each API request from the client to the server must contain all the necessary information for the server to fulfill that request. The server does not store client state between requests, ensuring that each request is independent.

• Benefit: This reduces server memory usage and makes scaling easier since any server can handle any request without knowledge of prior interactions.

Example: When a client makes an API call, the request includes authentication tokens or session data, so the server doesn't need to remember the client’s state.

Sources:

• REST API Design

2. Client-Server Separation

The client and server are independent systems. The client interacts with the API without knowledge of how the server is implemented, and vice versa. This separation of concerns allows both systems to evolve independently.

• Benefit: Client applications can change or update their frontend without affecting the server, and server updates can occur without impacting the client.

Sources:

• REST Principles

3. Uniform Interface

The principle of a uniform interface simplifies and decouples the architecture. It ensures that interactions between the client and server are standardized, regardless of the technology or device used.

• Elements of the uniform interface include:
  • Resource identification: Resources are uniquely identified using URLs.
  • Resource manipulation: HTTP methods (GET, POST, PUT, DELETE) are used consistently for interacting with resources.
  • Self-descriptive messages: Each response provides enough information for the client to understand it without extra information.
  • Hypermedia as the engine of application state (HATEOAS): Clients interact with the API dynamically by following links provided by the server.

Sources:

• RESTful API Best Practices

4. Cacheability

Responses from the server should define whether they are cacheable or not. If a response is cacheable, the client or intermediary can reuse the data without interacting with the server again. Proper caching reduces the number of requests sent to the server and improves performance.

• Benefit: This reduces latency and enhances scalability, as repeated requests for the same resource don’t need to be handled repeatedly by the server.

Sources:

• REST and Caching

5. Layered System

The REST architecture allows the API to be structured in layers. Each layer performs a different function, like routing, authentication, or load balancing, without the client knowing the system's internal workings.

• Benefit: This improves security and scalability by allowing intermediary servers to handle tasks such as load balancing, caching, or SSL termination without affecting the client-server interaction.

Sources:

• Layered System in REST

Conclusion

These principles help make REST APIs scalable, stateless, and easy to use. By adhering to them, developers can create APIs that are more robust, maintainable, and flexible.