A REST API and a SOAP API are two different animals best equipped to handle specific tasks over others.
Not sure which API is best for your needs?
If you’re learning the ins and outs of Epicor® ERP software and your developers need software components to communicate with each other, you’re going to need to use APIs.
Let’s say, for example, that you need your shopping cart to communicate with your payment page. An API is what makes that possible.
However, there’s a big difference between the types of APIs.
Here’s what you need to know about SOAP and REST and how they fit into your software.
What Is an API?
To the uninitiated, API sounds like a type of beer.
To the initiated, you may use the term so often that you try to order it at a bar.
An application program interface, or API, is a set of protocols, routines, and tools for building web resources. It’s also used to program graphical user interface components. Think of it like a user’s manual—it guides how various software components are supposed to work together.
Let’s say that your company has a form to sign clients up for appointments. You want that form to interface directly with Google Calendars to create an event with details of their meeting so that they can automatically save the event on their phone.
To do this, your form software has to talk directly to Google Calendars.
It also has to receive a response from Google Calendars, processes it, and send the relevant information (like a confirmation message) to a browser. This is where an API comes in.
An API is the part of the server that receives requests and sends responses.
There are several APIs, but two common ones are SOAP and REST APIs.
What Is a SOAP API?
Simple Object Access Protocol, or SOAP, is a message protocol that allows distributed elements of an application to communicate.
It’s used primarily for making remote procedure calls across machine and network boundaries.
As a protocol, it has four essential parts:
- Guidelines for message content and how to process it
- Encoding guidelines for data types in the application
- Guidelines for remote procedure calls and responses
- Guidelines for exchanging messages through specific protocols
It’s written using the Extensible Markup Language (XML), and each message consists of four parts:
- An Envelope element identifying it as a valid SOAP message
- An optional Header specifying additional requirements for the message
- A Body element containing the request or response
- An optional Fault element with information about errors during the API request or response
It uses HTTP as its delivery system, but it can also support other transport protocols.
In plain English, SOAP was designed to ensure that programs built on different platforms (or code in entirely other programming languages) could exchange data effectively.
What Is REST API?
Representational State Transfer, or REST, is an architectural style for providing standards between computer systems on the web, allowing different systems to communicate.
REST-compliant systems are known as RESTful systems.
The beauty of REST is its simplicity.
It relies on CRUD (Create, Retrieve, Update, Delete) to keep API protocols as easy as possible to understand, which means that anyone from an entry-level developer to a lead architect can make sense of them.
In addition, any developer who’s accustomed to working with the internet’s HTTP (i.e., any web developer today) will feel comfortable using REST API since it relies on the same basic constructs.
REST API vs. SOAP
With that in mind, it’s easier to understand the differences between REST and SOAP (and why REST has replaced SOAP for many developers).
SOAP is a protocol, while REST is an architectural style.
The most straightforward comparison is an envelope and a postcard. SOAP is like an envelope—there’s extra work required at both ends to package and unpackage it. REST is like a postcard—it’s light and consumes less paper (bandwidth).
By and large, developers have switched over to REST from SOAP. Only a handful of current APIs relies on SOAP exclusively.
This is in part because of compatibility. SOAP cannot use REST since SOAP is a protocol and REST is an architectural pattern. But REST can use SOAP as an underlying protocol since it’s just another protocol for the design to process.
When to Use REST and When to Use SOAP
There are certain situations better suited to REST and others suitable to SOAP.
For example, if you have lower bandwidth or limited resources, SOAP messages require more processing bandwidth so that that REST would be more effective. In addition, if you don’t need to maintain a state of information from one request to another, you should use REST.
An online shopping cart, for example, needs to retain the state of the cart items while transferring them to the payment page, which means you would need SOAP.
Making Your ERP Work for You
When applied to the right tasks, SOAP and REST APIs can significantly improve your software functionality and makes it easy to complete tasks that your customers take for granted.
Of course, if you’re acquiring the software your business needs, APIs may be further down the list. You’re just trying to make sense of the options in front of you.
Here’s why you should use ERP software.
If you’re ready to see the software in action, click here to check out Tomerlin-ERP’s Epicor® ERP services.