What is API - Application Programming Interface?

An overview of API

For beginners, API refers to the Application Programming Interface designed for effortless communication between two different applications.  This is why it’s often referred to as the middle person for the application.  While we discuss API, mentioning API security is essential, as it’s what protects the integrity of the apps, owned and used by the users.

Let’s understand the API meaning in detail. Today’s world is driven by IoT or the Internet of Things (IoT) wherein computing is integrated into day-to-day objects and operations. A real-life example of IoT implementation is using an app that can connect the phone with your refrigerator and allows you to operate from anywhere. Using that app, one can operate the refrigerator remotely, can find out what’s inside it, and even reduce the temperature.   

For developers, API is a great tool to use while exchanging information between microservices and containers and fast-paced communication. Just as integration and interconnectivity are crucial for application development, API drives and enhances application designing.

API Taken the Internet by Storm

APIs were functional as proprietary protocols even before Before the world got to know WWW and the internet. They are playing a crucial part of working wherever distributed networks are used for a restricted area, purpose, or organization. During the pre and post-internet era, APIs served the same purpose and made computing communication possible. 

When Web 2.0 breaks into the world, web-based tools become more than assistance to humans. They acted like lone warriors that could handle all the operations on their own. During this phase, REST rose to fame. It is used to explain API interfaces that are used later to architect the actual applications. 

The credit to offer  REpresentational State Transfer Framework (famously-known as REST) to the world goes to Roy Fielding, who suggested using such a framework in his Ph. D. work in the year 2000. It soon became a norm in the community of development experts and paved the path for OpenAPI. 

In the times of Web 3.0, APIs are playing a crucial role in communication between IoT and AI-driven devices. The customary request-response paradigm of API had to be modified as event-driven so that APIs involvement becomes more intensified.

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What are Web APIs?

An API is a set of instructions and tools that enable programmers to make their applications talk to one another. APIs are beneficial because they reduce the amount of code an application needs. For example, Web APIs give you access to a particular website’s data without having to write complicated code needed to access their data. On the other hand, if you were to create your own web application, you would need to create your own custom coding for interactions with data from a particular website. When programming websites with APIs, developers have access to the website’s functionality which is helpful for creating new apps or updating existing ones. 

Web APIs are also useful because they take care of things like authentication and authorization on behalf of the developer. This means that the developer doesn't have to worry about handling this themselves and can save time and effort by not having these tasks bog them down. If a developer has an app with multiple users logged in at once, an API allows those users access to each other's data too.

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What is an API endpoint? 

An API endpoint is a location where an API requests and receives data, either through a network or through a file. This can be a website URL, such as api.intercom.io/v3/messages?ids=1,479

or it could be a specific function in an application that accepts data and sends it to a specific API endpoint. For example, if you wanted to find out how many messages someone has sent on your app, you might send an API request to the /me/messages endpoint of your app's API.

This is what happens when two APIs communicate:

The first step is asking for permission for access to the second app's API endpoints. The second step is sending data using these endpoints. When the first app receives this data, it'll handle it according to its programming language and send back a response with whatever information they have on hand.

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What is an API gateway?

An API gateway is a type of software that sits between an external application and your app. It handles the traffic between the two, which can be pretty significant. If you’ve ever used Google Maps or Gmail, you might have noticed when you open the app for the first time that there are numerous prompts to log in with your Gmail address or sign up for a new Google account. That’s because both apps use an API gateway to talk to each other and set up their initial connection.

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API use cases

APIs are widely used in the world of app and web app development. They are the foundational elements of applications as they allow information exchange effortlessly. Some of the most customary and crucial use cases of API are as under:  

• Single Page Applications (SPA)

Using the REST API, the development of SPA or Single Page Application is accelerated. SPA apps make website content optimization possible and fits all the content on one page and grants an amazing user experience.

For the development of such applications, predefined CSS, JavaScript, and HTML files are used to begin the web server communication. 

Here, the REST framework is used for server-side communication while a particular kind of framework is deployed for client-side information exchange.

The commonly used REST API framework for SPA development in Jersey. Nancy Fx, Express Js, and ASP.Net Web API. The use of REST API for SPA development promotes improved scaling as it’s a stateless API framework and is not bothered by the use of one or many servers by the client for each request. This reduces the efforts invested to scale the application and eliminates the need of accessing the certain resource.

Other than REST API documentation, nothing binds clients and servers used in SPA development and makes them work as distinct beings. This independence promotes flexible development, testing, and deployment.

On the other hand, if a dynamic web pages framework is used, no such notable freedom is granted to the developers.

• Public API, enterprise B2B

For a long time, phone calls, fax, and email have served as key communication means for B2B operations. However, the gained technical momentum has promoted the use of integrations IoT-based information exchange. Restful API is playing a crucial role in automating enterprise B2B communication.

From customers’ point of view, releasing public APIs allows businesses to create a consumer-oriented application that makes communication with the outside world attain maximum utility.

The derived sluggishness of B2B processes can be curbed with the use of public APIs as they make business processes de-coupling possible and augment the machine-based interoperability. Public API allows B2B customers to expand the user-based, when the need for this action arises, without increasing the costing burden on the enterprise.

• Private API, internal API services

Using the private API, B2B customers trim down the time-to-market and launch new applications and tools quickly while causing no bottlenecks for existing workflows. When it comes to managing internal workflow, private APIs make figuring out the areas where there is a need for restructuring and modernization to make the enterprise composable.

The composable business model is an inventive process of breaking the complex functions into miniature pieces for easy handling. It promotes the strategic use of resources. Private APIs support internal communication at every level and make it efficient. 

Collaboration and information exchange becomes swift and secure when done using private APIs.

Internal APIs have made business intelligence analytics more precise as it provides precise details on system parts that might cause operational hindrance and can level up the response time.

• Service Mesh

It is a component of the infrastructure layer that is highly configurable and is of low latency. It’s used for handling the internal communication that happens at a large scale on the network-based structure. Use of these meshes warrants the swift, secure, and dependable information exchange related to the containerized and ephemeral application.

APIs are used for information exchange in the service mesh. As the data plane of a mesh makes contact with every possible packet or request that goes through the system, things become cumbersome.

The use of APIs like Universal Data Plane and xDS makes the job easier and allows swift operations related to checking system health, monitoring its performance, routing the incoming or outcoming requests, load sharing for balancing the burden of the system, service discovery, and user authorization for preventing malfunctioning. 

• Mobile Backends

An emerging service delivery model, mobile backend is used commonly for mobile-optimized solution development. Offered as MBaaS or Mobile Backend as a Service, this development model grants freedom to the developers to maintain the servers and server-related tools. An ideal MBaaS platform endows developers with assorted facilities including user management, push notifications, and social login plugins.  

MBaaS sources use flexible SDKs to leverage the endpoint connectivity for API. By doing so, MBaaS makes the development of frontend applications for Android and iOS OS using high-end technology like Flutter, Unity, Iconic, and ReactNative.

The use of MBaaS platform APIs allows developers to promote automation at fronts like workflow management, notification updates, and tasks planning.

Additionally, an inventive API encourages the generation of an application layer that is used for seamless information exchange between various systems and services used. Developers can contrive need-based services for newly added user clusters.

• IoT (Internet of Things)

IoT is one of the fastest-growing tech today, and is likely to back more than 80% of tools and software in coming times. Development of IoT devices/tools makes seamless with the use of APIs as they offer pre-defined communication routines and protocols for development.  

As IoT devices need to connect to customers or other network users’ devices to complete the information exchange done, using API ensures exposed information is secure, goes to the exact destination and gets along well other peer devices. Developers can create context-based applications competent enough to interact with the outside world without using the UI.

REST API is the most universally used API for IoT devices production and it proffers communication exchange over internet protocols. As IoT is driven by the internet, REST API encourages information exchange over the internet. Additionally, REST API allows developers to implement user authentication and permission-granting strategies.

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How to create an API

One of the most important things to do in your API makes sure it’s secure. In order to create an API, you need to know what permissions the API should require for use. You should limit access only to those who need them and keep your API private so that no one else can see what’s going on inside of it. 

• Plan the API 

Make a plan for how you want to use the API. Think about what actions need to be performed. Identify what data and functions are needed and then make sure that each step is accounted for in your plan. Once you have an idea of what you’re doing, identify the messengers that are needed and create an email or other contact point. You can even create a page on your website where people can sign up for notifications when new updates or changes happen.

• Build the API

The first step to using a new API is to build it. With this in mind, you can create an API for your app. This can be done by using the SDK provided with the API or by building your own. If you’re not familiar with software development, there are plenty of resources online that will help you learn how to do this. You’ll also need a few other things like a server and programming language (like Python) installed on your computer. Once you have everything set up, you’ll be able to start building your code.

• Test the API  

Test the API by either using a simulator or downloading an app. The best way to test an API is by using a simulator. Simulators are programs that are easy to use, open source, and run on any machine with Python installed (eg. Mac, Linux, Windows). 

• Document the API  

The first step to using an API is to document it in your code. This will allow you to use the same API with different programs and projects without having to reinvent the wheel every time. It’s also important that you document APIs on GitHub. The documentation will provide information about the API, how it works and what parameters it needs to be called.

• Market the API 

Marketing your API is relatively easy. The first step is to create a great product that people will want to use and build an application around it. Next, you’ll want to develop a marketing plan. You should consider how you will showcase your API, what kind of materials you need, what channels you’ll promote it on, and how you will measure its success.

The second step of marketing the API is creating demand for it by launching events or workshops. These can be anything from developer meet-ups to conferences where people can learn about APIs in general and your specific ones in particular. You should also consider developing a presence on social media like Twitter or Facebook where people might come across your product.

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What are the benefits of REST APIs: Integration, Innovation, Expansion, Ease of maintenance

One of the many benefits of using REST APIs is integration.  Some of the other great benefits include innovation and expansion, ease of maintenance, and cost-effective use.

REST APIs are excellent for innovation and are also good for future expansion. These APIs can also be used to maintain low costs when you're using them in your code. Why? Because these APIs often require less time and energy on your part.

Finally, if you want to use a REST API, it's easy to integrate into your code and make the connection with minimal effort. The rest is up to you!

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How to secure the REST API?

REST APIs are made up of resources that are accessed and manipulated by the client (app). In other words, the client is allowed to send requests to access these resources and then manipulate them.

• Authentication tokens of API

This allows the API to know who you are and what you're doing with it. Authentication tokens can be considered a type of digital credential or key. They come in many forms, such as API keys, OAuth tokens, or refresh tokens. The reason they’re so important is that they allow the API to give each user access to its resources without having to request the user's credentials again and again. This means applications can perform actions quickly without getting slowed down by authentication requests. 

• ‍API keys

An API key is a string of characters that apps use to authenticate with one another. They're typically used to let software applications talk to one another. A cryptocurrency exchange has an API that lets users trade cryptocurrencies like Bitcoin and Ethereum. The exchange’s website has an API that is meant for the app to communicate with. When you open the app, it will ask for your personal authentication key. This is what allows the app to connect and send/receive transactions from the exchange (in this case, Coinbase).

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API for different folks look really different

In the previous section, we provided a general overview of API to you. It’s usage is so wide and diverse that it works differently for different purposes. 

Back-end developer:

• Framework: A well-structured plan or strategy that defines how operations and processes will work;
• ‍Specification: A Swagger-based documentation that describes the functioning of REST or OpenAPI. For example, a document explaining the technicalities of circuit version 3, a clarification on everything related to Geo PC, a GraphQL schema that is different from the default version, or protobuf.
• ‍Data and Business Logic: It was impossible to imagine operating without HTML markup, but not anymore. Now, we can split data, logic and markup during the development today. Back-end developers prefer separating data and logic between clients (e.g. mobile app or browser). This helps them reuse and repurpose their code or data, e.g. single page applications and mobile apps can use the same data. Similarly, business integration, especially custom integrations, can be handled due to this.
• ‍Unified mobile, web and integration backends to improve and simplify the synchronization process.

DevOps:

• Specification meets Production: For example, if an endpoint returns 502 very often, shouldn’t you truy to find the reason and mitigate it? Same has to be done for other issues and needs.
• ‍Scaling: If an endpoint requires scaling to solve 504 Error, it is essential to find out the responsible microservice, optimal process, and orientation of the problem (e.g., REST API info GraphQL)

Security:

• New protocols: My firewalls, scanners, and other old tools stopped working on upgrading. What to do?!
• East-west security: The communication within my network is not monitored well?!
• New API security, networking or other IT compliance