Application Programming Interface (API) use and development - bounswe/bounswe2024group4 GitHub Wiki

What is API (Application Programming Interface)

An API, or application programming interface, is a set of rules or protocols that let software applications communicate with each other to exchange data, features and functionality.APIs simplify application development by allowing developers to integrate data, services and capabilities from other applications, instead of developing them from scratch. APIs also give application owners a simple, secure way to make their application data and functionality available to internal departments within their organizations. Application owners can also share or market that data and functionality to business partners or third parties.

How an API works

A simple way to understand how APIs work is to look at a common example—third-party payment processing. When a user purchases a product on an ecommerce site, they may be prompted to “Pay with Paypal” or another type of third-party system. This function relies on APIs to make the connection.

  • When the buyer clicks the payment button, an API calls to retrieve information—also known as a request. This request is processed from an application to the web server through the API’s Uniform Resource Identifier (URI) and includes a request verb, headers, and sometimes, a request body.

  • After receiving a valid request from the product webpage, the API makes a call to the external program or web server, in this case, the third-party payment system.

  • The server sends a response to the API with the requested information.

  • The API transfers the data to the initial requesting application, here the product website.

While the data transfer will differ depending on the web service being used, the requests and responses all happen through an API. There is no visibility on the user interface, meaning APIs exchange data within the computer or application, and appear to the user as a seamless connection.

Common examples for API use

  • Universal logins: A popular API example is the function that enables people to log in to websites by using their Facebook, Twitter or Google profile login details. This convenient feature allows any website to leverage an API from one of the more popular services for quick authentication. This capability helps save them the time and hassle of setting up a new profile for every web application or new membership.
  • Travel booking comparisons: Travel booking sites aggregate thousands of flights, showcasing the cheapest options for every date and destination. APIs enable this service by providing application users access to the latest information about availability from hotels and airlines.
  • Internet of Things (IoT): These “smart devices” offer added functionality, such as internet-enabled touchscreens and data collection, through APIs. For example, a smart fridge can connect to recipe applications or take and send notes to mobile phones through text message.

Steps to develop an API

  1. Define Clear API Objectives and Goals:Every successful API starts with a clear purpose. Define the objectives and goals of your API project before writing a single line of code. What problem does your API solve, and who are the intended users?
  2. Use Meaningful and Consistent Naming Conventions:Choosing meaningful and consistent naming conventions for your API endpoints, methods, and data structures is essential. It makes your API more intuitive and user-friendly, reducing the learning curve for developers interacting with it.
  3. Version Your APIs to Maintain Backward Compatibility:As your API evolves, it’s critical to maintain backward compatibility with existing clients. Versioning your API allows you to make changes and improvements without breaking the functionality for users of older versions.
  4. Implement Proper Authentication and Authorization Mechanisms:Security should be a top priority in API development. Implement robust authentication and authorization mechanisms to ensure that only authorized users can access your API’s endpoints.
  5. Document Your APIs Comprehensively:Comprehensive and well-maintained documentation is the lifeblood of any API. It serves as a reference guide for developers, making it easier for them to understand how to use your API effectively. Include clear examples, use cases, and details about endpoints, requests, and response formats.
  6. Provide Descriptive Error Messages and Status Codes:Users should receive informative error messages and status codes when something goes wrong in an API request. Well-documented error responses help developers quickly identify and resolve issues, improving the overall user experience.
  7. Validate Input Data and Handle Validation Errors:Input data validation is essential for the security and reliability of your API. Validate user input to prevent common security vulnerabilities like SQL injection and cross-site scripting. Ensure that you handle validation errors and provide meaningful feedback to users.
  8. Optimize API Endpoints for Performance and Scalability:API performance can significantly impact the user experience. Optimize your API endpoints for speed and scalability. Use techniques like caching, pagination, and asynchronous processing to enhance performance while ensuring your API can handle increasing loads of user requests.
  9. Implement Rate Limiting and Throttling to Prevent Abuse:To prevent abuse or overuse of your API, implement rate limiting and throttling. Set limits on the number of API requests a user or client can make within a specific time frame. This helps maintain fair usage and protects your API from abuse.
  10. Use Appropriate HTTP Methods (GET, POST, PUT, DELETE) for CRUD Operations:Follow the HTTP methods (GET, POST, PUT, DELETE) convention for Create, Read, Update, Delete operations. This aligns your API with standard practices, making it more intuitive for other developers to work with.

Sources