5 Guidelines for Designing RESTful APIs Effectively

RESTful Application Programming Interfaces (APIs) utilize HTTPs for receiving and executing requests. Developed from Representational State Transfer (REST) concepts, it is primarily designed for the purpose of data transfer between web-based services. Owing to its streamlined bandwidth consumption, it is preferred over Simple Object Access Protocol (SOAP) for developing APIs.

How Do RESTful APIs Work?

RESTful APIs decompose transactions into meaningful parts and functions using GET, POST, PUT, and DELETE HTTP requests to perform CRUD operations. The stateless element means RESTful APIs retain no data during transactions and can be implemented in cloud applications since they incorporate high scalability and swift deployment.

Advantages of RESTful Programming Architecture

With the advent of cloud technology, RESTful APIs are becoming increasingly trending and are considered as an integral part of web development as they are well suited for web-based communications. Because the client and server are decoupled in nature, code fragments can be efficiently debugged which enables rapid development independent of language barriers. Moreover, the APIs can be modified easily to integrate both new demands and improve on existing code. Capitalizing on their advantages, tech giants ranging from search engines such as Google to social media platforms such as Twitter are deploying them extensively in their architecture.

Main Objectives of RESTful Programming

The following are the main ideas behind RESTful programming:

• Employing a common identifier for resources; in most cases, Uniform Resource Identifiers (URIs) are used.
• Using preexisting methods, primarily HTTP (GET, POST, PUT, DELETE) to manage resources. RESTful programming if extremely diverse and can incorporate many other transport mediums, but presently HTTP is the most used one.
• Rather than relying on the identifier, the request itself serves as the basis for the resources fetched.
• Identifying and presenting the interconnections between resources, the connections are directly mapped to the representation.
• The representations for mentioned resources also detail their usage and constraints.

4 Core HTTP Methods for RESTful APIs

RESTful APIs are capable of utilizing HTTP for performing Create, Run, Update and Delete (CRUD) operations. The following are the 4 main HTTP methods related to RESTful programming:

• GET Method: Launches a request for fetching specified data.
• POST Methods: Launches a request to the server database for creating a specified resource.
• PUT Method: Launches a request to the server database to update specified resource and if not found, to create it.
• DELETE Method: Erases the specified resource from the server database.

Elements of RESTful API

For an API to be classified as being RESTful, the following elements should be present:

• Stateless: The client serves as storage for the session and the server does not save and data being received by the client.
• Client and Server: The client and server are decoupled, meaning they do not share dependencies and hence can be modified without directly reflecting changes on one another.
• Caching: For optimizing performance, caching is enabled for the clients, similar to how web browsers function.

5 Guidelines for Developing Effective RESTful APIs

Developing a successful and stable RESTful API is dependent on factors such as features, overall performance and usability for both developers and average users. The following 5 guidelines form the core of any RESTful API designing strategy devised to ensures its quality and functionality.

Implement Secure Socket Layer (SSL) Encryption

The internet allows global access to APIs which leads to a broad spectrum of access points, ranging from homes and private locations to public ones such as libraries and waiting areas. Computers can act as third parties between servers and users to sniff data which is otherwise private in nature, leading to security risks. Through SSL, the communication is encrypted and can only be accessed by the sender and receiver. Moreover, the SSL encryption eliminates needless effort required to authenticate API requests individually and replaces the process with access tokens.

Return Latest Rather Than Previous Responses

Any changes in a specific fragment of API can result in modifications to interrelated resources that must be updated to return the latest response. HTML methods such as PUT and PATCH can cause changes in timestamps which are otherwise not specified for modifications. Return the modified representation so the user does not have to repeatedly request the API to return the latest representation.

Detailed Documentation of API

Understandability is among the core features of a successful API, which can be achieved through detailed documentation. Developers often refer to documentation during integration, debugging, and maintenance phases since it comprehensively explains the entire API, its features, and functionality.

Documentation should be focused on detailing the API behavior and responses generated as a result of specified queries. If the API is subject to modifications, the documentation should be updated according to the implemented changes.

Managing API Versions

Versioning an API is critical for ensuring efficiency during runtime and generating exceptions against unsupported requests which are directed towards API modules which have been subject to modifications. This, in turn, prevents the API from generating unexpected behavior and compromising its functionality, increasing its stability and tolerance to invalid commands. By allowing backward compatibility, older versions of the API can be enabled which allows both versions to provide functionality, which streamlines the transition process during major version changes.

APIs are subject to continuous improvements to accommodate evolving user requirements, which necessitates strict versioning protocols. Versioning allows developers to create an incremental record of API development and any changes can be backtracked in case issues are encountered. Since change is gradually introduced with previous API versions remaining functional until new ones have been properly analyzed, neither the functionality nor stability are affected during the transition.

Combine API With Relevant Resources

APIs are commonly separated from their related resources to optimize size and performance. This streamlined approach more than often results in limiting the overall functionality and negatively impacts user experience, since it fails to deliver according to expectations. Autoloading resources relevant to API features not only enhance overall functionality but also removes the authentication required to enable individual API requests.  

While developing a RESTful API is indeed a challenging task which requires factoring in numerous elements, it can be simplified by following a predefined approach. Integrating these five guidelines in any RESTful API designing strategy will ensure that it is flexible for modifications, is secure, and features high understandability for both developers and end users.