Do you want to link your app to Facebook so it can generate posts automatically, or to Instagram so you can repost photos with certain hashtags?
You could also wish to include YouTube videos on your website. Application programming interfaces allow you to perform all of these tasks and more (APIs).
Different applications can “speak” to one another in a secure and standardized manner thanks to APIs like the Instagram API, Facebook API, and YouTube API.
In other words, a program can take features or data from another piece of software and utilize them to improve its own features or user experience. But how can apps make these requests, process them, and respond to them in a fashion that others can understand?
That depends on how the API was created. When discussing API (application programming interface) designs, it’s usual to compare SOAP vs. REST, two of the most prominent API paradigms.
As soon as SOAP APIs (Simple Object Access Protocol) became the gold standard for firms like Oracle, Sun, and PayPal, there was an equal and opposite response a year or so later towards REST APIs from Google, Amazon, and eBay.
In this post, we’ll compare and contrast SOAP APIs with REST APIs so you can decide which is best for your purposes.
We will begin by defining the API.
What is API?
Application Programming Interface is referred to as API. APIs are essentially a collection of methods and functions that enable the development of apps. They get access to the information and functions of different programs, services, or operating systems.
They serve as a sort of middleman between various software systems. They enable “talking” between two unconnected programs.
Let’s take the example of a stockbroker who is actively involved in trading and the financial markets. A collection of automated trading algorithms can be connected to the trader’s favorite trading broker platform through an API. This enables you, the trader, to execute electronic transactions or see real-time quotations and pricing data.
What is REST?
True “web services” APIs include REST (Representational State Transfer). REST APIs are built on URIs (Uniform Resource Identifiers, of which a URL is a special kind), the HTTP protocol, and the incredibly browser-compatible JSON data format.
The SOAP protocol, as we already stated, might possibly also be used. REST APIs can be easy to create and grow, but they can also be enormous and difficult—it all depends on how they’re created, expanded, and what they’re intended to do.
Resource constraints, reduced security requirements, browser client compatibility, discoverability, data health, and scalability are some reasons you would wish to develop an API to be RESTful—things that actually apply to web services.
REST (typically) uses a straightforward URL in place of an XML request. Although there are rare circumstances when you must offer more details, the majority of RESTful web services only use the URL technique.
The four HTTP 1.1 verbs GET, POST, PUT, and DELETE can be used by REST to carry out operations. Unlike SOAP, REST does not need the answer to be in XML.
The objective is that you can get the results you need in an easy-to-parse format within the language you’re using for your application.
- REST emphasizes simplicity above all else, owing to HTTP protocols.
- The web is best suited for REST. It is compatible with browsers because JSON is used as the data format.
- REST is renowned for its outstanding scalability and speed.
- Client-server connections and architectures are made more accessible by REST APIs. If it is RESTful, it is constructed using this client-server model, with round trips between the two parties passing data payloads.
- REST APIs employ a solitary standard interface. Ensuring that all apps connect uniformly and through the same gateway, streamlines how applications communicate with the API.
What is SOAP?
Its own protocol, called SOAP (Simple Object Access Protocol), is a little more complicated than REST since it specifies more standards, including those related to security and message delivery.
These inherent norms do come with a little bit extra overhead. However, they can be a decisive factor for businesses that need more extensive security, transaction, and ACID (Atomicity, Consistency, Isolation, Durability) compliance capabilities.
For the sake of this comparison, it’s important to note that many of the benefits of SOAP don’t often apply to web services applications, making them more suitable for enterprise-type scenarios.
Higher degrees of security (such as when a mobile app interacts with a bank), messaging apps that require dependable communication, interacting with legacy systems, or ACID compliance are a few reasons you would wish to design an application utilizing a SOAP API.
The messaging capabilities offered by SOAP are entirely based on XML. Older internet-incompatible technologies like the Distributed Component Object Model (DCOM) and Common Object Request Broker Architecture were replaced by SOAP when it was first created by Microsoft (CORBA).
The reliance on binary communications causes these systems to fail. Over the internet, XML messaging like that used by SOAP functions better.
- The security of SOAP is significantly tighter. WS-Security is a built-in standard that offers SOAP additional enterprise-level security capabilities if needed in addition to SSL support.
- Successful/retry reasoning for trustworthy messaging performance. Because REST lacks a standardized message mechanism, it can only retry when communication fails. Even when using SOAP intermediates, SOAP offers end-to-end dependability due to its built-in successful/retry logic.
- SOAP already complies with ACID standards. By dictating how transactions can interact with the database, ACID compliance minimizes anomalies and safeguards the consistency of a database. Because ACID is more cautious than other data consistency models, it is frequently used when managing sensitive transactions, whether financial or otherwise.
- It is simple for programmers to comprehend since SOAP is a totally XML-based communication.
- The XML messaging protocol is an addition to the HTTP protocol.
- Communications from one computer to another computers can be disseminated via SOAP messaging.
- Client-server architecture can also be implemented. A SOAP protocol message can be used by the client to call a remote procedure call that is situated server-side.
REST Vs SOAP Differences
An API is intended to primarily show specific components of the business logic of an application on a server. While REST makes use of URIs for the same purpose, SOAP employs a Service Interface for this.
REST APIs are created after the data, whereas SOAP APIs are developed after the functionalities that the API illustrates. Compared to SOAP, which is more function-driven, REST is a more data-driven design.
Data that has been marked as cacheable can be utilized by browsers again without requiring them to make a new request to the server. Saving time and effort is a benefit of this.
Responses won’t be cached at the HTTP level since SOAP queries are submitted via POST requests, which the HTTP standard deems non-idempotent. If you want to employ caching, you must still build the necessary techniques as REST APIs don’t include this implementation.
3. Resources & Bandwidth
Due to the envelope-style payload transfer used by SOAP, there is a modest increase in overhead, which necessitates extra bandwidth. REST’s lightweight nature is a benefit in these situations because it is generally utilized for web services.
WS-security, which SOAP supports and is slightly more thorough than SSL at the transport level, is desirable. Incorporating enterprise-level security measures with it is also a perfect fit.
End-to-end encryption using SSL is supported by both SOAP and REST, and REST can use HTTPS, the secure variant of the HTTP protocol.
5. Handling Payloads
Data transmitted through the Internet is referred to as a payload. A payload that is considered “heavy” needs additional resources. Compared to SOAP, which utilizes XML, REST often uses JSON and HTTP to assist decrease the payload.
A specialized Client library with generated code must typically be used by the Client to access SOAP APIs because of their extremely stringent communication contract.
As a result, SOAP offers a lesser level of abstraction than REST and is more closely connected with the server.
When to use REST?
- Creating public APIs: REST APIs are preferred for building public web services because they are seen to be simpler to use and adopt than SOAP APIs. Additionally, SOAP offers several built-in security measures that REST does not have, although these characteristics are not required when working with open data and services.
- Constructing mobile apps: REST is perfect for building mobile applications since it is small, effective, stateless, and cacheable.
- Utilizing scarce server resources and bandwidth: All requests to a REST API must be stateless, which means that each interaction is separate and each request and response contains all the data necessary to complete that interaction. The server does not save records of previous requests since it treats each one as a fresh request. As a result, the server requires far less memory and operates more quickly because a request does not necessitate further action or the retrieval of historical data.
When to use SOAP?
- Creating private APIs, particularly for large businesses: SOAP is perfect for corporate applications since it enables data flow in a decentralized, distributed environment and contains several online security features.
- Using a transport protocol other than HTTP as the underlying layer: SOAP is not dependent on HTTP as the underlying layer. Depending on your application, you could utilize SMTP (Simple Mail Transfer Protocol), JMS (Java Messaging Service), or another transport protocol.
- Working with stateful operations: In contrast to requests to REST APIs, requests to SOAP APIs are stateful, meaning the server saves information about the client and utilizes it across a chain of requests or operations. Even while this uses more server bandwidth and resources, it’s crucial for carrying out routine or linked actions, like bank transfers.
The comparison between REST and SOAP APIs makes it quite evident that REST is preferable to SOAP. Even yet, there are situations where SOAP API is required. In certain instances, web services are created by combining REST and SOAP APIs.
Therefore, the use case will determine which API style will work the best.