Complete Guide to Full REST API: History, Principles, and Differences

History and Emergence of REST API

REST API, or Representational State Transfer Application Programming Interface, emerged in the late 1990s as a result of Roy Fielding’s work. In his 2000 doctoral dissertation, Fielding described REST as an architectural style for building distributed systems. His work focused on creating an architecture that allowed systems to interact with each other via a simple and universal protocol — HTTP.

REST gained popularity due to its simplicity and alignment with internet standards, unlike more complex protocols such as SOAP (Simple Object Access Protocol). SOAP, unlike REST, was aimed at corporate systems and was more complex because it required additional specifications and XML as the primary data exchange format. REST, on the other hand, provided a lighter, more universal, and accessible approach, making it ideal for rapid API development.

Key Principles of REST API

REST API is built upon several key principles that ensure client-server interaction:

1. Client-Server Architecture. The client and server must be clearly separated. The client is responsible for the interface and user interaction, while the server handles requests and manages data. This separation allows both parts of the system to be developed independently.
2. Statelessness. Each request from the client to the server must contain all the necessary information for the server to process it. Session state between requests is not stored on the server. This ensures reliability and simplifies scalability.
3. Uniform Interface. The API must be consistent and predictable. Standard HTTP methods (POST, GET, PUT, DELETE) are used for each action — creating, reading, updating, and deleting data.
4. Caching. Server responses can be cached on the client-side to reduce server load and increase performance.
5. Layered Architecture. REST implies a layered system architecture where different layers can handle various tasks such as security, load balancing, or data processing.

What is Full REST API?

Full REST API is an extension of the basic REST API principles that involves strictly adhering to all REST principles and standards. While many systems call themselves RESTful, they don’t always fully implement REST.

RESTful API vs. Full REST API: Differences

Many systems call their APIs RESTful, but this doesn’t always mean they fully adhere to REST principles. Here are the key differences between RESTful API and Full REST API:

1. Adherence to REST Principles. Full REST API implements all REST principles, while RESTful API may deviate by using sessions or breaking interface uniformity.
2. HTTP Methods. In Full REST API, the rules for using HTTP methods are strictly followed. For example, POST is only used to create new resources, and PUT is used for updating existing ones. In RESTful APIs, this rule can be broken, such as using POST to update a resource.
3. Independence of Requests. Full REST API requires that each request be completely independent of the previous ones. RESTful APIs may store sessions or state on the server, which violates the principle of independence.
4. Consistent Interaction Standard. Full REST API ensures a predictable and uniform interface, while RESTful APIs may have variations in implementation, making them more difficult to use.

Why Full REST API?

Full REST API offers several advantages that make it popular among developers:

1. Scalability. Since each request is independent, systems built on Full REST API can be easily scaled horizontally, which is crucial for high-load applications.
2. Flexibility. Full REST API can be used with any client that supports HTTP, such as web browsers, mobile apps, IoT devices, and other servers.
3. Technology Independence. Full REST API is not tied to a specific platform or technology. It can be implemented in any programming language, making it universal.
4. Performance. Thanks to caching requests and statelessness, systems using Full REST API work faster and require fewer resources.

Examples of Full REST API Usage

Full REST API has become the foundation for many large web services, such as Twitter, GitHub, and Google. These companies implement strict REST standards to ensure compatibility with various clients and platforms, as well as to facilitate the development and maintenance of their APIs.

Key Milestones in the Development of REST API

• 1994: The initial emergence of the idea of distributed systems based on the client-server model.
• 1999-2000: Roy Fielding publishes his doctoral dissertation, in which he formulates the basic principles of REST.
• 2000s: REST API begins gaining popularity due to its simplicity and efficiency, especially in the context of web applications.
• 2010s: REST API becomes the primary method of client-server interaction in web development. Major companies begin adopting Full REST API to enhance the scalability of their services.

Alternatives to REST API

While REST API remains a popular standard for building web services, there are several alternative technologies that offer different approaches for client-server interactions:

1. GraphQL. Developed by Facebook, GraphQL provides a flexible and powerful way of working with data. Unlike REST, where each action requires a separate request, GraphQL allows the client to request only the needed fields in a single query. This reduces the number of requests and minimizes network load. However, due to its flexibility, GraphQL requires a more complex infrastructure and data management on the server.
2. gRPC. gRPC is an open-source framework developed by Google that uses HTTP/2 and the binary data format Protocol Buffers, making it more performant and efficient compared to REST. gRPC supports bi-directional streaming, which is particularly useful for microservices and high-load systems.
3. OData. OData (Open Data Protocol) is a protocol developed by Microsoft for working with data. It supports functions like filtering, sorting, field selection, and data aggregation at the API level, making it easier to work with large datasets.
4. JSON-RPC. JSON-RPC is a simple remote procedure call (RPC) protocol that uses JSON as the data format. Unlike REST, JSON-RPC allows you to directly call functions on the server, making it more suitable for some specialized tasks.
5. SOAP. SOAP (Simple Object Access Protocol) is an older, yet still widely used protocol for exchanging structured messages between applications. It is primarily used in enterprise systems where security and reliability of transactions are important, but its complexity and bulkiness make it less popular for modern web applications.

Each of these alternatives has its strengths and weaknesses, and the choice between them depends on the project’s requirements, system performance, and the level of control over the data.

Popular Tools for Testing REST API

There are many tools available for testing and debugging REST APIs, which simplify interacting with services, checking requests, and analyzing server responses. Here are some of the most popular ones:

1. Postman. One of the most widely used tools for testing APIs. Postman offers a user-friendly graphical interface for creating requests, viewing responses, and supporting various HTTP methods. Postman also allows for automated testing and the creation of request collections for collaborative work.
2. Swagger. Swagger is a toolkit for documenting, developing, and testing APIs. Swagger UI enables visualization of APIs and testing requests directly in the browser. It’s widely used due to its integration with the OpenAPI Specification, which simplifies the creation of API documentation.
3. Insomnia. A powerful and easy-to-use tool for testing REST and GraphQL APIs. Insomnia supports automated requests, environment management, and advanced configuration options for sending requests, making it popular among developers.
4. JMeter. JMeter is a load testing tool that can also be used for testing REST APIs. It allows for simulating large amounts of traffic to measure server performance under load.
5. SoapUI. SoapUI is a tool for testing both SOAP and REST APIs. It supports functional, load, and automated testing, and offers powerful integration capabilities with other systems.
6. Katalon Studio. This tool offers integrated solutions for testing web applications, mobile apps, and APIs. Katalon Studio supports both REST and SOAP APIs, providing an easy way to automate tests.

Using these tools enables developers and testers to quickly and effectively verify APIs, ensuring the quality and reliability of services under various operational scenarios.

The Future of REST API

As technologies evolve, more APIs are becoming hybrid. While REST remains the dominant standard, new approaches such as GraphQL and gRPC offer alternatives for more complex queries and interactions. However, Full REST API, with its reliability, simplicity, and universality, will continue to play an important role in the web development ecosystem.