API architectural styles determine how applications communicate.

The choice of an API architecture can have significant implications on the efficiency, flexibility, and robustness of an application.

So it is very important to choose based on your application's requirements, not just what is often used.

Let’s examine some prominent styles:

𝗥𝗘𝗦𝗧

A cornerstone in web services, REST leverages HTTP methods for streamlined operations and a consistent interface.

Its stateless nature ensures scalability, while URI-based resource identification provides structure.

REST's strength lies in its simplicity, enabling scalable and maintainable systems.

Learn more about REST here: What Is a REST API? Examples, Uses, and Challenges

𝗚𝗿𝗮𝗽𝗵𝗤𝗟

Whilst REST uses multiple endpoints for each resource and necessitates multiple requests to obtain interconnected data;

GraphQL uses a single endpoint, allowing users to specify exact data needs, and delivers the requested data in a single query.

This approach reduces over-fetching, improving both performance and user experience.

Learn more about GraphQL here: What is GraphQL and how does it work?

𝗦𝗢𝗔𝗣

Once dominant, SOAP remains vital in enterprises for its security and transactional robustness.

It’s XML-based, versatile across various transport protocols, and includes WS-Security for comprehensive message security.

Learn more about SOAP here: What Is a SOAP API?

𝗴𝗥𝗣𝗖

gRPC is efficient in distributed systems, offering bidirectional streaming and multiplexing.

Its use of Protocol Buffers ensures efficient serialization and is suitable for a variety of programming languages and use cases across different domains.

Learn more about gRPC here: What is gRPC?

𝗪𝗲𝗯𝗦𝗼𝗰𝗸𝗲𝘁𝘀

For applications demanding real-time communication, WebSockets provide a full-duplex communication channel over a single, long-lived connection.

It's popular for applications requiring low latency and continuous data exchange.

Learn more about WebSockets here: Examining use cases for asynchronous APIs: webhooks and WebSockets

𝗠𝗤𝗧𝗧

MQTT is a lightweight messaging protocol optimized for high-latency or unreliable networks.

Its pub/sub model ensures efficient data dissemination among a vast array of devices, making it a go-to choice for IoT applications.

Learn more about MQTT here: Home automation with MQTT

API architectural styles are more than just communication protocols; they are strategic choices that influence the fabric of application interactions.

There is no best architectural style.

Each offers unique benefits, shaping the functionality and interaction of applications. It's about making the right choice(s) based on your application's requirements.

Once you've chosen your API architecture style and you're ready to start testing, Postman collections are widely regarded as the go-to solution: Test your API using the Collection Runner