REST vs SOAP - Difference Between SOAP vs REST API with Examples

The two most popular approaches to online data transmission are Representational State Transfer (REST) and Simple Object Access Protocol (SOAP). They both define how to build application programming interfaces (APIs), which enable communication between web applications. The main distinction between the two is that SOAP is a protocol, while REST is not.

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REST is a set of architectural principles that define how data should be transmitted. It is not a protocol, which means it does not define how the data should be formatted. Instead, it relies on standards like HTTP and XML to do that. SOAP, on the other hand, is a protocol. It defines how data should be formatted before it is transmitted. This makes SOAP more complex than REST.

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What is REST API?

A REST API is a web service that uses HTTP requests to GET, PUT, POST, and DELETE data. A REST API can be used to access resources such as text files, images, and videos. A REST API can also be used to access data from a database. A REST API is different from a SOAP API. A SOAP API uses XML to define the structure of the data being exchanged. A REST API uses JSON to define the structure of the data being exchanged. A REST API is lightweight and easy to use. It is also easy to scale.

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What is SOAP?

SOAP is an acronym for Simple Object Access Protocol. It is a communication protocol that allows different applications to communicate with each other. SOAP is based on XML, which is a markup language used to encode data. SOAP messages are typically sent over HTTP, which is a network protocol used to transport data. SOAP is a platform-independent protocol, which means that it can be used with various operating systems and programming languages. SOAP messages consist of three parts: an envelope, a header, and a body. The envelope contains information about the message, such as the sender and receiver. The header contains information about the message itself, such as the encoding type and the message id. The body contains the actual data being exchanged between the sender and receiver.

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Examples of REST & SOAP

What are REST APIs used for?

REST API provides a lot of flexibility  and control over the data and function that is being accessed by the clients. REST APIs can be used for anything from retrieving data from a server to creating or modifying data on the server. We have listed some of the use cases of REST APIs below:

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1. Cloud applications:

One of the most popular use cases for REST APIs is to access cloud-based applications. With the help of REST API, clients can easily connect to these applications and perform various operations such as retrieving data, creating new data, updating existing data, or deleting data.

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2. Microservices:

REST API also plays a vital role in microservices architecture. In a microservices architecture, each service is independent and can be deployed or updated separately. By using REST API, clients can easily connect to these services and access the functionality they need.

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3. Mobile applications:

REST APIs are also used in mobile applications. With the help of REST API, mobile applications can connect to the server and retrieve or update data.

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4. Cloud services:

REST API can also be used to access cloud-based services. You can use  REST API to connect to these services and perform various operations.

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5. Web use:

REST APIs can be accessed from any type of client, including web projects, iOS apps, IoT devices, and Windows Phone. This makes it easy to build the infrastructure for your organization without worrying about being tied to a particular client-side technology. These are some of  the most common use cases of REST API. There are many other use cases as well, such as for managing content, for e-commerce applications, for social networking applications, and so on. If you need to build an API for your application, then REST API is a good choice.

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What are SOAP APIs used for?

SOAP API provides a way to communicate between different applications or systems. It defines the structure of the data being exchanged and is platform-independent.  Large enterprise environments often utilize SOAP API in order to take advantage of its platform-independent structure and ACID-compliant transactions. SOAP API also allows for greater control and flexibility over client/server interactions. Some common use cases for SOAP API include:

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1. Banking

Banks use SOAP API in order to send secure messages between different applications. This allows for sensitive information to be exchanged without the risk of being intercepted by third-party applications.

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2. Healthcare

SOAP API is also commonly used in healthcare environments in order to exchange patient information between different systems. This helps to ensure that all relevant parties have access to the most up-to-date information.

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3. E-commerce

SOAP API can also be used in e-commerce applications to facilitate the exchange of order and product information between different systems. This allows for a streamlined ordering process and helps to ensure that all parties have the most up-to-date information.

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4. Complex methods

SOAP API can be used to express complex methods in a more easily understandable format. This is especially beneficial for large enterprise environments where there may be a lot of different applications or systems that need to communicate with each other. These are some of the most common use cases for SOAP API. However, there are many other use cases as well. You can even use SOAP API to build your own web services. The possibilities are endless.

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The main differences between SOAP & REST

1. Caching:

When it comes to caching, SOAP and REST differ in how they are handled. With SOAP, requests are sent using a POST request, which is considered non-idempotent by the HTTP standard. This means that responses won't bez cached at the HTTP level. However, you can still implement caching mechanisms yourself if you wish. With REST, on the other hand, data can be marked as cacheable, which allows it to be reused by browsers without initiating another request back to the server. This can save a lot of time and effort.

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2. Architecture:

Another key difference between SOAP and REST APIs is the way in which they are architected. SOAP uses a complex, multi-layered architecture consisting of clients, servers, transport protocols, and message formats. In contrast, REST APIs use a simple, uniform architecture that is based on the principles of Representational State Transfer (REST). This allows for easier development and deployment, as well as improved scalability. When choosing an API for your application, it is important to consider the complexity of the architecture.

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3. Security:

SOAP and REST APIs both provide a way to secure data communications. SOAP supports WS security, which is more comprehensive than SSL and makes it ideal for integrating with enterprise-level security tools. 

Both SOAP and REST support SSL for end-to-end security, but REST can also use the more secure HTTPS protocol. Therefore, either way, you choose to go, you can be confident that your data will be securely transmitted.

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4. Bandwidth and Resources:

SOAP requires more bandwidth than REST because SOAP's envelope-style payload transport consumes slightly more resources. However, since REST is designed specifically for web services, its leaner structure makes it advantageous in these scenarios.

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5. Handling Payloads:

When it comes to payloads, REST APIs have a clear advantage over SOAP APIs. With REST, data is typically sent using JSON or HTTP, which helps to reduce the overall size of the payload. This is in contrast to SOAP, which uses XML, which can often be quite large and cumbersome. In addition, SOAP APIs typically have a very strict communication contract that often requires the use of a specific Client library with generated code in order to access them.  This can be quite limiting as compared to the more flexible REST approach. As a result, REST APIs tend to provide a higher level of abstraction and are less tightly coupled to the server.

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When to use REST API?

Below are some points of when it makes sense to use REST APIs:

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• REST API can be used to build a monitoring system based on API responses.

• REST API can be used to help protect against DoS attacks.

• REST API is a good option for error reporting and monitoring.

• REST API can be used to identify if two resources are the same.

• REST API can be used to avoid re-fetching resources.

• REST API is a good option for resource attacks.

• REST API can be used to query exactly what you want whenever you want it.

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When to use SOAP?

Here are a few examples of when you can use SOAP:

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• SOAP can be useful for stateful operations, as it offers a WS* structure.

• SOAP can be useful for asynchronous processing and subsequent invocation, as it offers extra features that can help establish a robust security framework.

• SOAP can be useful for formal means of communication, as it offers rigid specifications.

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SOAP vs REST: Summary Table

For SOAP

• SOAP is based on the Simple Object Access Protocol

• SOAP depends mostly on XML and, together with schemas, to create a very defined messaging framework.

• It requires more bandwidth.

• Uses XML for payloads.

• It supports WS security.

• SOAP uses service interfaces to present its capabilities to client applications.

• SOAP APIs have a very strict communication contract.

• It can be less scalable.

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For REST

• REST is based on the principles of Representational State Transfer.

• REST uses simple, uniform architectures.

• It requires less bandwidth.

• Uses JSON or HTTP for payloads.

• It supports SSL for end-to-end security.

• REST uses resource URIs to present its capabilities to client applications.

• REST APIs have a flexible communication contract.

• It can be more scalable.

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Which API is the Best for your Project?

Now that we've looked at the key differences between SOAP and REST APIs, it's time to decide which one is right for your project. To conclude the debate of SOAP vs REST for this article, web service developers usually prefer a RESTful architecture unless SOAP is concretely the wiser decision. This can be the case for enterprise apps that require more resources and have more complex security requirements. RESTful web services are typically more lightweight, making them ideal for apps that need to run on mobile devices or other resource-constrained devices. 

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They're also generally easier to develop and use since they don't require the use of a specific SOAP Client library. In addition, REST APIs tend to provide a higher level of abstraction, making them less tightly coupled to the server. On the other hand, SOAP web services can be a good choice for apps that require a more formal means of communication or for those that need to support WS-security features. They can also be a good choice for stateful operations or for asynchronous processing and subsequent invocation.In the end, the best decision for your project will come down to a balance of these factors and to the specific requirements of your project.

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Challenges With SOAP API

1. WSDL file

The first challenge that can be faced when using SOAP API is the WSDL document. This document can be complex and contain a lot of information on the actions that the web service is able to do. This can make it difficult for customers to understand all of the information contained within it.

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2. Document Size

Another challenge that might be faced when using SOAP API is the size of the document. The file can be quite large, which can make it difficult to download and use. Moreover, its bandwidth is limited, which is a significant challenge indeed!

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Challenges in REST API

1. Lack of security

One of the challenges that can be faced when using REST API is the lack of security. This is because REST API uses HTTP, which is not a secure protocol. Therefore, it is important to make sure that the data being sent over the network is encrypted.

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2. Lack of state

Another challenge that might be faced when using REST API is the lack of state. This means that each request made to the server is a new request, and the server does not keep track of any previous requests. This can make it difficult to maintain data consistency.

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REST & SOAP Alternatives

Here are some key alternatives for REST APIs and SOAP APIs:

• GraphQL

• JSON

• gRPC

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1. GraphQL:

GraphQL is a data query language that provides an alternative to REST and SOAP APIs. It is designed to make it easy to get the data you need from a server, and it is also easy to make changes to the data on the server.

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2. JSON:

JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy to read and write. SOAP's quick and easy transmission process makes it a viable option in many cases.

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3. gRPC:

gRPC is an open-source system that uses HTTP/2 to connect services in a microservices architecture developed by Google. Its main benefits are more lightweight messages than JSON, built-in code generation, high performance, and support for more connection options like streaming data. Using gRPC can help reduce the amount of transmitted data over the network while improving both the performance and flexibility of your microservices architecture.

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Conclusion:

In conclusion, both REST API and SOAP API have their own advantages and disadvantages. The best decision for your project will come down to a balance of these factors and to the specific requirements of your project. With boltic, you can automatically generate REST API or SOAP API from your database without having to write a single line of code. Boltic provides you with lightweight and comprehensive API solutions that are open source, modular, and available on-premise or in the cloud. 

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We are a no-code, easy-to-use platform that makes it simple to get started with designing and building APIs. Our wide range of features includes the ability to connect to various data sources and excellent documentation that makes learning how to use our tool a breeze. If you need any assistance, our support team is always available to help. Contact us today to learn more about how we can help you build the perfect API for your needs.

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