Exploring API Architectural Styles

Have you ever wondered how apps talk to each other? Like, how Netflix grabs your movie list, or how a payment gateway verifies your card in seconds? Or maybe how your crypto tracker (because, let’s be honest, we all hope it’s finally going up) fetches live prices? Yep, you’ve got APIs to thank for that.

APIs (Application Programming Interfaces) are like digital waiters that take your order (a request), deliver it to the kitchen (server), and bring back what you asked for (the response). But not all APIs are built the same way.

In this article, we will be looking at four major API architectural styles: SOAP, REST, GraphQL, and WebSocket.

Let’s go

SOAP – Simple Object Access Protocol

SOAP is a protocol, it’s basically a set of rules that dictate how applications communicate. It uses XML for message formatting and has very specific rules about how those messages should look. It works over different network protocols like HTTP, SMTP, and TCP, which makes it versatile.

Let’s say we want to send an email, but instead of the regular way, we have to fill out 10 different forms, get them stamped by a notary, and then wait three business days for approval. Sounds exhausting, right? That’s SOAP for you, it’s secure, reliable but a bit too bureaucratic. It’s reliable and secure, which is why industries dealing with sensitive data use it.

REST – Representational State Transfer

REST is an API architectural style that is simple, flexible, and lightweight. Unlike SOAP, REST is like sending a simple email where you don’t need to fill out forms or wait for approval. You just type your message, hit send, and it’s done. It uses JSON or XML for data exchange.

The thing about REST is that it's stateless; each time you send a request, it’s like starting fresh. The server doesn’t remember anything from the previous request, so the client must include all the necessary information to process it. This keeps things fast and efficient, but it also means that you can't rely on the server to track previous interactions.

Everything in REST revolves around resources, and each resource has its own unique URL. REST APIs use standard HTTP methods to interact with these resources:

• GET: Retrieves data

• POST: Create new data

• PUT: Updates data

• DELETE: Remove data

It focuses on client-server communication and allows developers to interact with resources efficiently without overcomplicating things.

GraphQL

GraphQL is an open-source query-based API architecture. It was developed by Facebook to address some of REST’s limitations, particularly over-fetching and under-fetching of data. It executes queries using a type system you define for your data.

So, instead of fixed endpoints, the client sends a query specifying the structure and fields of the data they require. The server then responds with a JSON object that matches the query, ensuring the client gets only what's necessary.

It's like when you go to a buffet and only want two specific dishes. REST would serve you the entire menu, while GraphQL, on the other hand, lets you pick exactly what you want. So, you don’t need to make five different requests just to get what you want.

WebSockets

WebSockets are a communication protocol that enables full-duplex communication between a client and a server. WebSocket keeps a single and long-lived connection, allowing instant two-way communication. No need for repeated requests like traditional HTTP.

If REST is like sending emails, WebSocket is like a live chat where you send a message, and boom, the other person gets it instantly. WebSockets work by upgrading an HTTP connection to a WebSocket connection using a handshake process.

Future trends

If there’s one thing we can count on in tech, it is that nothing stays still for long, and APIs are no exception. From how they’re built to where they’re hosted, API architectures are changing fast. Here are two key trends shaping the future:

1. A Mashup of Styles

Today, most large organizations are mixing things up. They are using REST, GraphQL, and AsyncAPI in the same ecosystem to serve different needs; gone are the days when companies were stuck with just REST and called it a day. GraphQL is growing fast because of its ability to let clients pull just the data they need in a single, precise query.

In fact, a 2024 survey by Hygraph found that over 60% of developers are already using GraphQL in production, and AsyncAPI downloads have exploded, jumping from 5 million to 17 million in just a year.

All of this means one thing, API management tools will need to grow in supporting multiple API formats, syncing data from different styles, and giving devs one dashboard to rule them all.

2. Serverless and Edge Computing

APIs are no longer confined to traditional servers. With serverless computing and edge architecture stepping into the spotlight, APIs are now leaner, faster, and closer to the user. Serverless APIs scale automatically and cost less (you only pay for what you use), while edge computing brings processing power closer to the end user. When you combine these two, you get a fast response time and lower latency.

3. Smarter API Management Is on the Rise

As we shuffle REST, GraphQL, AsyncAPI, serverless functions, and edge deployments, expect a rise in platforms that support REST, GraphQL, WebSocket, etc all from one dashboard. The future of API architecture isn’t about picking one style, it’s about harmonizing them all.

Conclusion

Choosing the right API style depends on what you’re building.