Application Programming Interface (API)

Open standards for IT are often associated with APIs

What is an API?

API (or Application Programming Interface) are coding interfaces that allow two applications to communicate with each other.
For example, an interface that allows your application to retrieve data from a website or online grocery store
The API will need proper authentication and security to ensure only authorized access.

Components of a Well-Designed API

• 1. Support multiple languages/formats
  Different apps support different markup languages, including JSON, XML and CSV.
• 2. Documentation
  Documentation is necessary to explain how to use the API and to meet the requirements of DevOps – a methodology for automating the technological processes of assembling, configuring and deploying software.
• 3. Community
  Developers need help from other developers.
  Often many of the most widely used APIs are supported by robust developer communities.

API types

• REST APIs
  REST APIs, also known as RESTful APIs, stand for Representational State Transfer. Recently, REST APIs have grown in popularity as a part of web services. REST APIs are designed for developers to make requests and receive responses through HTTP functions. There are four different HTTP commands that REST is based on. These include GET, PUT, POST and DELETE. When you open Instagram and search for the latest and greatest meme of the day, the app uses a REST API.
• SOAP APIs
  SOAP stands for Simple Object Access Protocol. REST is an architectural style and SOAP is a protocol defined by a standard. SOAP relies on XML-based systems and programming, so it tends to have larger and more expensive data. SOAP APIs also provide a higher level of security. A common use case is an application interacting with a financial institution.
• RPC APIs
  RPC stands for Remote Procedure Call. RPC APIs were the earliest form of APIs because they are designed to execute a block of code on another server. When used over HTTP, it can become a web API.

Difference between public API and private API

Public APIs are the most common examples of what an API is. They are intended to be shared with everyone. External developers can create applications using the capabilities of these APIs.

Private APIs are often used within an enterprise to improve collaboration. While the API itself is also open as a public API, the difference is that it is only open to those granted access. They can leverage existing enterprise application functionality to enable company employees to communicate more effectively.

Why are APIs important?

• APIs allow different systems to seamlessly interact and exchange data. This is fundamental to powering most modern web applications and mobile devices.
• APIs allow developers to reuse functionality that has already been created. For example, by calling the YouTube API, you can build video playback functionality into your application without having to create a video streaming service from scratch.
• APIs significantly speed up software development, allowing developers to focus on creating unique product features.
• Public APIs enable innovation by allowing developers to leverage existing platforms. For example, many new weather apps have been created by giving developers access to weather data APIs.
• APIs allow you to create scalable software that can serve millions of users.

If each application had to create its own servers and infrastructure, rapid scaling would be impossible. But by using common APIs, applications can exponentially expand their reach and user base.

Bottom line, APIs power most of the applications we use today, allowing systems to communicate, exchange data, provide access to complex functionality, and innovate on existing platforms.

How do APIs work?

APIs work by having two components – a client and a server. The client is the application or system that needs access to functionality, while the server is the system that hosts the API.
For example, let’s take an API that tells you your IP address on the Internet. Our application will be a client accessing a special website, which is the server.
Common APIs are REST and SOAP. REST has become popular in recent years due to its simplicity. Below is an example of how the REST API works:
The client sends an API request to a specific URL endpoint on the server. For example, to obtain your computer’s IP address, a client can send a GET request to: https://api.ipify.org?format=json.
The server communicates with the underlying database or software systems and packages the response. It sends back a response with data, usually in JSON format.
The client application processes this response and uses it for its own purposes.
In short, the client application makes API calls to a remote server, which sends back structured data – and this data can then be displayed or manipulated in the client application.

Real API examples

Let’s look at some real-life examples of popular APIs that you can use regularly:

• Google Maps API — allows any application to embed Google Maps. This makes it easy to add mapping functionality without having to build complex mapping software from scratch.
• Twitter API — Allows applications to access and display tweets and Twitter data such as follower counts, profiles, etc. This is how Twitter clients and management applications are created.
• Stripe API — allows apps and websites to easily accept payments without having to deal with the complex financial and regulatory requirements associated with payment processing.
• Slack API — enables automation and creation of custom integrations with the Slack messaging platform. Applications can receive event notifications through this API.
• Open Weather Map API – provides current and future weather data such as precipitation probability, temperature, etc. that weather applications rely on.
• YouTube API — allows you to embed YouTube videos into other applications and create custom YouTube clients..

These are examples of the thousands of APIs that provide functionality to the apps and websites we use regularly.

API benefits

• APIs hide all the “complex” details “under the hood” – this allows developers to easily use functionality without having to build everything from scratch.
• Saves time and effort — using existing APIs and code saves significant time and effort during development.
• Reusability — unce an API is created and publicly available, any number of applications can use it, resulting in reusability.
• Scalability — APIs allow you to easily scale to large user bases without having to directly handle the load.
• Provide core functionality — whether it’s payment processing, mapping, messaging or more, APIs provide core functionality out-of-the-box.
• Monetization — companies like Google and Twitter provide APIs that allow them to monetize their platforms by further expanding usage..

API Security Settings

APIs also pose security risks that need to be considered and mitigated as much as possible.

• Authentication – Secure your APIs by implementing authentication mechanisms such as OAuth (or Open Authorization) to ensure that only authorized clients can access them.
• Access Control – Establish proper access controls to limit API access to only the functionality required by each client.
• Encryption – Use HTTPS and encrypt all API messages to prevent data from being tracked in transit.
• Rate Limiting – Implement rate limiting to prevent abuse and “denial of service” attacks through the API.
• Input Validation – Validates all input data to prevent attacks such as SQL injection that compromise the server via the API.
• Monitoring – Track API usage statistics, errors, and latency to stay on top of performance and quickly detect new threats.
• Documentation – Build security directly into the API documentation so developers understand proper usage from the start.

Documentation – Build security directly into the API documentation so developers understand proper usage from the start.