Know your API protocols: Differences and when to use

As a developer in today’s interconnected software landscape, you have a multitude of options when it comes to integrating your applications with other systems. The protocol you choose to facilitate this communication is crucial, as it determines how flexible, fast, and reliable the integration will be. 

In this article, you will get an overview of the three most popular API protocols – SOAP, REST, and GraphQL. 

Plus, learn about their key characteristics, strengths, and weaknesses, so you can make an informed decision about which protocol is most suitable for your project needs.

Types of API protocols

To build a scalable API architecture, it is important to know the available protocols and their strengths. Understanding these foundational protocols and how to leverage them strategically has become an essential skill for any developer.

The three most popular options are:

• SOAP (Simple Object Access Protocol) is an XML-based protocol for accessing web services. It is highly structured and standardized, making it a popular enterprise choice. However, its verbosity leads to increased bandwidth usage and latency.
• REST (Representational State Transfer) uses HTTP methods (GET, POST, PUT, DELETE) to manipulate data and resources. It returns data in XML, YAML, HTML, or JSON formats. REST is lightweight, flexible, and easy to use, making it suitable for most web APIs. However, it lacks built-in security and discovery features.
• GraphQL is a query language for APIs that provides a complete and understandable description of the data in the API. It allows clients to request exactly the data they need from the server. GraphQL has gained popularity due to benefits like increased flexibility, efficiency, and developer experience. However, it requires complex server-side logic and may be overkill for simple APIs.

SOAP API Protocol: When to Use It

When to Use SOAP

SOAP (Simple Object Access Protocol) is a standards-based web services protocol ideal for enterprise and B2B applications. It has some key characteristics:

• Uses XML format to send requests and responses, allowing for strict data typing and validation. This results in tightly coupled interfaces with little flexibility.
• Built on top of the HTTP protocol, but hides many HTTP features. SOAP APIs are not RESTful.
• Provides rich metadata through an XML-based WSDL (Web Services Description Language) document. This enables automated code generation and integration.
• Supports WS-Security, WS-Transactions, and other enterprise features. This makes SOAP suitable for business processes and transactions.
• Tends to be slower and more bandwidth-intensive than other protocols due to the verbose XML format.

REST API Protocol: Why It’s So Popular

Pros of REST API

As an API protocol, REST (Representational State Transfer) has several benefits that explain its popularity. First, REST is easy to use and implement since it relies on a simple set of methods (GET, POST, PUT, DELETE) to handle CRUD (create, read, update, delete) operations. This simplicity makes REST accessible to developers with little experience in API development.

REST is flexible and can handle diverse types of calls and return different data formats like JSON, XML, YAML, etc. This flexibility allows REST to connect various systems and share data in a standardized way.

REST is scalable and can evolve to accommodate growth in users or functionality. New resources and methods can be added without impacting existing ones. Caching and other performance-enhancing techniques can also improve REST API efficiency at scale.

JSON-RPC API Protocol: Simple Yet Powerful

What is JSON-RPC?

JSON-RPC is a simple protocol that defines a set of rules to facilitate communication between a client and a server. It uses the JSON (JavaScript Object Notation) format to encode its messages. JSON-RPC enables remote procedure calls (RPCs) between applications, allowing you to call functions that exist on a remote server.

When Should You Use JSON-RPC?

JSON-RPC is a good choice if you need a simple protocol to connect a server and a client. It is lightweight, easy to implement, and language-agnostic. You can use JSON-RPC with any programming language that supports JSON. Some ideal use cases for JSON-RPC include:

• Creating a basic API to connect a frontend and a backend.
• Building a simple microservice architecture.
• Creating plugins or extensions that need to communicate with a main application.

Benefits of JSON-RPC

Some of the main benefits of the JSON-RPC protocol are:

1. Simplicity: JSON-RPC is easy to implement and use. It has a simple specification and uses JSON, which most languages already support.
2. Flexibility: JSON-RPC works with any programming language and framework. You have the flexibility to choose any language or framework you want.
3. Scalability: JSON-RPC can be used to build scalable APIs and microservice architectures.

gRPC API Protocol: For High-Performance Microservices

gRPC: An Efficient Protocol for Microservices

gRPC is an open source RPC (Remote Procedure Call) framework developed by Google. It uses HTTP/2 for transport, Protocol Buffers as the interface description language, and provides features like authentication, bidirectional streaming and flow control.

• gRPC is ideal for building high performance microservices in distributed systems. The lightweight nature of Protocol Buffers and HTTP/2 enable low latency and high throughput communication between microservices.
• gRPC supports streaming, allowing server-side push and bidirectional streams. This makes it suitable for use cases like chat applications, live dashboards, and online gaming.
• gRPC is strongly typed and uses Protocol Buffers to define service interfaces and message formats. This results in smaller payloads and less parsing overhead compared to other protocols.
• gRPC has client libraries in 10+ languages, so you can easily build polyglot systems and microservice mesh architectures.
• gRPC can be used in combination with REST for public APIs, while using gRPC internally for microservice communication. This allows leveraging the benefits of both protocols.

GraphQL API Protocol: Flexibility and Efficiency

Flexibility and Efficiency

The GraphQL API protocol provides developers with increased flexibility and efficiency.

• GraphQL allows clients to describe exactly what data they need in a query, enabling the server to return just that data. This prevents overfetching and underfetching of data.
• GraphQL uses a strongly-typed schema to describe capabilities of the API, allowing clients to validate queries before executing them. This helps catch errors early and ensures only valid queries are sent to the server.
• A single GraphQL endpoint can handle queries for multiple types of data, reducing the number of API calls needed. For example, a single query could request data about users, posts, and comments.
• GraphQL enables efficient data fetching by allowing clients to request nested data in a single query. For example, a query could request a list of users along with their posts and comments. This reduces the number of roundtrips to the server.
• The GraphQL schema is introspective, meaning clients can query the schema for details about what queries and data types are available. This allows clients to dynamically build queries based on the server’s capabilities.

Getting Started With the Best API Protocol

Getting Started With REST

When designing an API, the REST protocol is a popular choice for developers. REST APIs are based on HTTP requests and are versatile, flexible, and easy to get started with.

To build a basic REST API, you need to:

1. Determine the nouns (resources) in your API and assign a URL to each. For example, /users, /posts.
2. Allow the standard HTTP methods (GET, POST, PUT, PATCH, DELETE) to operate on those resources. For example, GET /users to retrieve a list of users, POST /users to create a new user.
3. Return JSON or XML data to represent resources and HTTP status codes to indicate the result of operations. For example, a status code of 201 Created for a successful POST request.
4. Make resource representations (JSON/XML documents) self-descriptive so clients know how to interact with the API. For example, including a link to related resources in resource representations.
5. Design resource URLs to be hierarchical and follow a consistent pattern. For example, /users/1234 to refer to user with id 1234.
6. Use HTTP headers and status codes correctly. For example, Location header to point to a newly created resource after a POST request.

Conclusion

In closing, as you embark on integrating APIs into your software applications, take the time to evaluate which protocol best suits your needs. Consider the complexity of your system and data, how much control and flexibility you require, the experience of your developers, and your scalability requirements. While REST may be a good starting point, GraphQL could be better suited for complex applications that demand high performance and flexibility. 

The options available provide a lot of power and control, so do your research and choose wisely. With the right API protocol powering your applications, the possibilities for connectivity and innovation are endless.

FAQs : Understanding the basics 

What is meant by API protocol?

API stands for Application Programming Interface. It is a set of protocols, routines, and tools for building software applications. An API protocol is a set of rules that allow programs to communicate with each other. It defines the way in which data is transferred between different systems.

What is the difference between API and protocol?
The main difference between API and protocol is that an API is an interface that allows two different applications to communicate with each other while a protocol is a set of rules that govern how data is transmitted over a network.

Why RESTful is better than SOAP?
RESTful APIs are better than SOAP because they are more flexible and less complex. RESTful APIs use HTTP requests to post data (create), read data (read), update data (update), and delete data (delete). RESTful APIs are also easier to use than SOAP because they use standard HTTP methods such as GET, POST, PUT, and DELETE. RESTful API are more complex because they require more bandwidth and processing power than RESTful APIs. They also require more code to be written on the client side.