Definition
An application programming interface (API) is a collection of rules and protocols that enable various software apps to send data, interact, and communicate. APIs allow developers to utilize the functionality of existing program services or components without having to construct everything from scratch.
Types of Internet APIs
- Public APIs: These are open-source and accessible to all businesses and developers. They normally include moderate authentication and authorization.
- Partners APIs: They are only accessible to chosen and verified outside consumers and developers. Partner APIs are usually employed to facilitate business-to-business (B2B) activities.
- Internal or private APIs: Internal APIs are only employed within a specific corporation to link data systems. For instance, a private API may connect to a company’s HR and payroll systems.
- Composite APIs: Composite APIs commonly blend the data and functionalities from various APIs into one interface. These APIs combine numerous functionalities to offer a more cohesive experience for developers.
How an API Functions
APIs outline an array of rules and protocols governing how various software systems interact and communicate. Here are the steps involved:
- A client app communicates with an API by sharing a request with particular instructions and details.
- The API validates the requests and ensures proper authorizations.
- The API can then link to other systems to obtain or modify details as required.
- After processing the request, the API returns a message to the client app.
- The response is arranged in a certain way, such as a labelled box, to facilitate understanding by the client application.
- The API will notify the client application of any issues by sending an error text or signal.
Application Programming Interface Examples
- Universal logins: This allows users to sign into sites by utilizing their Google, Twitter or Facebook profile credentials. This excellent tool enables any website to utilize an API from one of the most well-known providers for quick authentication, saving users time and the trouble of creating a new profile each time.
- Internet of Things (IoT): The ‘smart devices’ provide extra functions like web-enabled touchscreens and data collection via APIs. For instance, a smart fridge can link to recipe apps and text notes to mobile phones. Moreover, inbuilt cams connect to several apps, allowing users to view the refrigerator’s contents remotely.
- Travel booking comparisons: Travel booking sites compare many flights to find the most cost-effective options for each date and destination. APIs support this service by offering app users access to recent airline details and hotel availability. APIs help save time and effort when looking for accessible flights by allowing for the independent interchange of data and requests.
- Mapping apps: They use core APIs to show dynamic or static maps. Moreover, these apps use other APIs and tools to provide users with traffic warnings, speed limits, directions, areas of interest, and communication while tracking goods in motion.
- Twitter: Every tweet includes descriptive core attributes such as author, timestamp of when it was posted, message, geolocation metadata, and a unique ID. The platform provides developers with access to essential parts of public tweets and the ability to reply and post tweets on other websites using the organization’s API.
- SaaS application: APIs are key in software-as-a-service (SaaS) applications. Services like customer relationship management tools (CRMs) typically have several embedded APIs that enable organizations to integrate with existing apps, such as messaging and email apps. The integration significantly reduces data silos and time spent switching between apps for sales and marketing activities.
Application Programming Interface Protocols
- Simple Object Access Protocol (SOAP): SOAP, developed with XML, allows endpoints to share and accept data via HTTP and SMTP. SOAP APIs simplify information sharing across applications or programs running in distinct environments or written in various languages.
- XML-Remote Procedure Call (XML-RPC): This protocol uses a particular XML format to share data. Despite being older than SOAP, XML-RPC is simpler and more lightweight, utilizing less bandwidth.
- JSON-RPC: Just like XML-RPC, JSON-RPC is a remote process call. However, instead of XML, the data is transmitted using JavaScript Object Notation (JSON).
- Representational State Transfer (REST): REST API is also known as RESTful API. It is a suite of Internet API architecture principles that follow specific REST architectural constraints. REST APIs can be built using SOAP protocols, but the two are typically regarded as competitors.