What are the API Types?

There are many different types of APIs that are used for multiple purposes and are designed for individual and unique use cases. The most used types of APIs are classified according to their usage patterns and architectures.

1 –Types of APIs According to Their Intended Use

1. Open APIs

It is also called public APIs which are available to any other users. Open APIs help external users to access data and services. It is an open-source application programming interface that we access with HTTP protocols. These types of APIs are available to the public by companies, allowing external users to access specific functionalities or data. It is a very popular type of API in modern API development, which involves consistency, reusability, and easy integration of services and data from different platforms. It has a developer-friendly environment but the developers who create these Open APIs have to be well aware of the documentation to the efficient usability of API.

2. Internal APIs

It is also known as private API, only an internal system exposes this type of API. These are designed for the internal use of the company rather than the external users. As Private APIs are used for internal use, data formats can be negotiated, depending on the use cases. These can also be created for better collaboration of data and services among the different teams. It has a very controlled environment within the organization so the utilization of this API is more effective and promotes collaboration, and reusability, and ultimately leads to a more productive development process.

3. Composite APIs

It is a type of API that combines different data and services. The main reason to use Composites APIs is to improve the performance and speed up the execution process and improve the performance of the listeners in the web interfaces. Sometimes, interacting with some websites contains a very complex and time-consuming process, so to solve this problem, we use Composite API. It allows developers to access a set of related functionalities through a single API endpoint which simplifies the complex interactions and provide a great user experience.

 

4. Partner APIs

It is a type of API in which a developer needs specific rights or licenses in order to access. Partner APIs are not available to the public. These APIs are provided by third-party companies that allow external developers to access their services and integrate them into their applications. It is a very secure and controlled way for external systems to collaborate with the company and access the capabilities of our system. One of the best examples of Partner API is Amazon API which allows online businesses to connect with Amazon.com by providing various functionalities like inventory management, shipping options, and analytics of their business.

 

Top 6 Most Popular API Architecture Styles You Need to Know (with Pros, Cons, and Use Cases)

In this article, we will discuss about 6 Most Popular API Architecture Styles: REST, SOAP, GraphQL, gRPC, WebSocket, and Webhooks.

APIs are ways for software to talk to each other and share data. There are different ways to design and build APIs. Let’s see the top 6 API Architecture Styles and their pros, cons, and Use Cases.

REST

REST is a way to use web standards and addresses to work with data on a server. They’re popular, easy to implement, and use HTTP methods. Most of the web services you interact with daily, like Twitter or YouTube, are powered by Restful APIs. For example, a client can use GET to get data, POST to make new data, PUT to change data, or DELETE to remove data. The data are usually in formats like JSON or XML.

Pros

·        It is simple and easy to use and understand.

·        It follows the rules of the web and uses existing standards and protocols.

·        It is fast and can handle many requests, as it supports caching and statelessness.

·        It is flexible and can use different formats and media types.

Cons

·        It does not have a clear contract or schema, which can make it unclear and inconsistent.

·        It does not support complex queries or operations, which can make it need many requests and get too much or too little data.

·        It does not handle errors or exceptions well, as it uses HTTP status codes that are not always clear or correct.

Usage

REST is good for situations where:

·        The data model is simple and stable.

·        The clients and servers are not dependent on each other.

·        The speed and scalability are important.

SOAP

SOAP is s style that uses XML messages and a predefined contract to exchange information between applications. It has a clear and strict contract, and it supports complex queries and operations, but it is complex, verbose, and not scalable or performant.

Pros

·        It has a clear and strict contract that ensures interoperability and compatibility.

·        It supports complex queries and operations, such as transactions, security, or authentication.

·        It handles errors and exceptions well, as it uses SOAP faults that provide detailed information.

Cons

·        It is complex and verbose to use and understand.

·        It does not follow the principles of the web and adds overhead to the existing protocols.

·        It is not scalable or performant, as it does not support caching or statelessness.

·        It is not flexible or extensible, as it requires changes to the contract for any modifications.

Usage

SOAP is suitable for scenarios where:

·        The data model is complex and dynamic.

·        The clients and servers are tightly coupled and dependent.

·        It’s heavily used in financial services and payment gateways where security and reliability are key

GraphQL

GraphQL is not just an architectural style but also a query language, allowing clients to ask for specific data as they need. This means no more over-fetching or under-fetching of data. You ask for exactly what you need. This leads to more efficient network communication and faster responses. Facebook developed GraphQL to deliver efficient and precise data to its billions of users. Now it’s used by companies like GitHub and Shopify. Its flexibility and efficiency make it a strong choice for applications with complex data requirements. It also supports mutations to change the data, and subscriptions to get live updates when the data changes.

Pros

·        It works with any server language or framework, as it uses its own schema definition language.

·        It has a single endpoint, which makes it more efficient than REST, where multiple requests might be needed to get enough data.

·        It is strongly typed, which makes sure the data is consistent and compatible between the client and the server.

·        It lets clients fetch only the data they need, which avoids over-fetching or under-fetching of data.

Cons

·        It is complex and hard to use and understand, as it requires learning a new syntax and logic.

·        It does not support caching by default, which can affect performance and scalability.

·        It does not handle errors well, as it always returns HTTP 200 status code, even if there are errors in the GraphQL layer.

Usage

GraphQL is good for situations where:

·        The data model is complex and dynamic, as it can handle nested and relational data.

·        The clients and servers are not dependent on each other, as it lets clients define their own data requirements.

·        The bandwidth and performance are important, as it reduces the amount of data transferred.

gRPC

gRPC is modern, high-performance, and uses protocol buffers. It’s a favorite for microservices architectures, and companies like Netflix use gRPC to handle their immense interservice communication. However, if you’re dealing with browser clients, gRPC might pose some challenges due to limited browser support.

Pros

·        It has a clear and strict contract, which ensures interoperability and compatibility between services.

·        It supports complex queries and operations, such as streaming, bidirectional communication, authentication, or encryption.

·        It is fast and efficient, as it uses binary format and HTTP/2 features to reduce latency and bandwidth.

Cons

·        It is complex and hard to use and understand, as it requires generating and compiling protocol buffer files.

·        It does not follow the principles of the web, as it uses custom headers and methods that are not compatible with standard web tools or browsers.

Usage

gRPC is good for situations where:

·        The data model is complex and dynamic, as it can handle structured and unstructured data.

·        The services are dependent on each other, as it allows services to invoke each other’s methods directly.

·        The speed and efficiency are important, as it minimizes the overhead and maximizes the throughput.

WebSocket

WebSocket is all about real-time, bidirectional, and persistent connections. It’s perfect for live chat applications and real-time gaming, where low-latency data exchange is crucial.

Pros

·        It is faster and more efficient than HTTP, as it uses a single connection and does not need headers or cookies for each message.

·        It can send and receive different types of messages over the same connection, such as text, binary, or streaming data.

·        It can push data from the server to the client without waiting for a request, which enables real-time and event-driven communication.

Cons

·        It’s not supported by some older browsers or proxies that do not understand the WebSocket protocol or the upgrade header.

·        It’s not secure by default, as they do not use encryption or authentication unless they use the wss:// scheme, which is similar to https:// for HTTP.

·        It does not store any information about the connection or the messages on either side, which means they are not stateful.

Usage

WebSocket is good for situations where:

·        The web application needs fast and interactive data exchange, such as chat, gaming, or streaming.

·        The web application needs bidirectional and multiplexed communication, where both sides can send and receive multiple messages of different types at the same time.

·        The web application needs real-time and event-driven communication, where the server can send data to the client without waiting for a request.

Webhooks

Webhooks are a way for servers to send messages to clients when something happens. They use HTTP callbacks or POST requests to deliver payloads that contain information about the events. The clients register their webhooks with the servers by providing URLs that can receive the payloads. Webhook is all about event-driven, HTTP callbacks, and asynchronous operation.

Pros

·        It is simple and easy to use and understand, as it uses standard HTTP methods and formats.

·        It follows the principles of the web, as it leverages existing standards and protocols.

·        It is scalable and performant, as it supports asynchronous communication without polling or waiting.

Cons

·        It does not have a clear or strict contract, which can lead to inconsistency and ambiguity between servers and clients.

·        It does not support complex queries or operations, it only sends one-way notifications without confirmation or feedback.

·        It does not handle errors well, It does not provide retries or acknowledgments in case of failures.

Usage

Webhooks are good for situations where:

·        Event-driven notifications ( GitHub uses webhooks to notify your other systems whenever a new commit is pushed.)

·        The data model is simple and stable, as it can handle basic types and fields.

·        The servers and clients are not dependent on each other, as they do not require direct communication or coordination.

·        The performance and scalability are important, as they reduce the load and latency of the communication.

API Style	Pros	Cons	Use Cases
REST	Simple, flexible, scalable, web-friendly	No clear contract, no complex queries, poor error handling	Data-oriented applications, web services, caching, statelessness
SOAP	Clear contract, complex queries, good error handling	Complex, verbose, not scalable, not web-friendly	Transactional applications, security, authentication, interoperability
GraphQL	Language agnostic, single endpoint, strongly typed, data efficiency	Complex, hard to use, no caching, poor error handling	Complex and dynamic data models, client-driven requirements, bandwidth and performance
gRPC	Language agnostic, clear contract, complex queries, fast and efficient	Complex, hard to use, not web-friendly, not flexible	Complex and dynamic data models, microservices communication, speed and efficiency
WebSocket	Fast and efficient, bidirectional and multiplexed communication, real-time and event-driven communication	Not supported by some older browsers or proxies, not secure by default, not stateful	Fast and interactive data exchange such as chat, gaming or streaming
Webhooks	Simple, easy to use, web-friendly, scalable	No clear contract, no complex queries, poor error handling	Simple and stable data models, event-driven notifications, performance and scalability

 

 

 

API'ler ve Web Servisleri

 

A web service and an API are two very similar concepts, making it difficult to understand their similarities and differences.

What is a Web Service?

A web service is a way for two machines to communicate with each other over a network. A web server running on a computer listens to requests from other computers. When a request is received from another computer over the network, the web service returns the requested resources. These resources can be in formats such as JSON, XML, an HTML file, images, audio files, etc. It is important to note the necessity of making requests over a network.

 

So, what is the difference?

While not all APIs are accessible over the internet (network), web services always need to be accessed over a network. That's the key difference.

 

All Web Services are APIs, but not all APIs are Web services.

A web service is a subset of an API. Examples of standardized architectural styles to create APIs include REST API, SOAP API, GraphQL Web Service API, etc.

 

 

 

 

 

Web Service	API
A type of API accessed over a network connection	Allows applications to interact with each other in a standardized way
All Web Services are APIs	Not every API is a Web Service
Uses protocols like REST, SOAP, GraphQL	No specific communication style restriction
Can be hosted only on platforms like IIS	Can be hosted in IIS or within an application
Closed-source, XML-based, usable only by clients understanding XML	Open-source, supports various formats like JSON, XML, usable by clients understanding different formats

 

Zeynep Sultan EROĞLU