Whether you want to build a website or web application, why web API is mandatory. So, what actually is an API and when do you require it?

API, Application Programming Interface resembles the online web services that are used by the apps at the client-side to retrieve and update information. An API would hold on to a central logic of an application irrespective of the number of client apps utilizing it.

In order to better understand this, let us consider an example, where there are a number of mobile apps supported by different platforms and a web app. If there is no centralized web API, then each client app will have its own embedded business logic which would enable it to connect directly to the database in order to retrieve, update and manipulate the data. Hence, implementing any change to the client apps will be a complex process as each of the apps would be required to maintain in sync with each other. Moreover, in case of any update, it would be required to make changes to each and every app individually. Hence, this requires more effort, takes more time and costs, and can also result in a lot of bugs or errors in the application.

So, a better way is to use a central API to get, update, or change the data. It will be easy to maintain the apps and it would be required to make changes only in one place. In the case of ASP.NET, a web API is an easy way to implement RESTful web services using the .NET framework. The RESTful web services are those that use HTTP as the underlying method for communication. An ASP.NET web API is basically defined as a framework that enables the development of HTTP services to reach out to client entities like browsers, devices, or tablets. ASP.NET Web API can be used with MVC for any type of application. Hence, .NET web APIs are very important for ASP.NET web application development.

Back End For Native Mobile Applications:

If you’re looking for an backend to build native mobile apps that don’t have support for SOAP, ASP.NET Web API is a good choice. Any native application that runs on a device, other than the Windows one can utilize ASP.NET Web API for a a backend. Thus, a Web API can be used native apps that need web services, but not SOAP support.

Routing:

ASP.NET Core Web APIs leverage attribute-based routing, allowing developers to define routes directly on controller actions using attributes like `[HttpGet]`, `[HttpPost]`, `[HttpPut]`, and `[HttpDelete]`. This enables clean and expressive route definitions without the need for configuring route tables.

Model Binding and Validation:

ASP.NET Core provides built-in model binding and validation mechanisms, making it easy to bind incoming request data to action method parameters and automatically validate them based on model annotations and validation attributes.

Content Negotiation:

ASP.NET Core Web APIs support content negotiation, allowing clients to request data in different formats (JSON, XML, etc.) based on their preferences. This enables seamless integration with a wide range of clients with varying content requirements.

Middleware Pipeline:

ASP.NET Core’s middleware pipeline enables developers to plug in custom middleware components to handle cross-cutting concerns such as logging, authentication, authorization, and exception handling. This promotes modular and reusable code organization while ensuring separation of concerns.

Follow RESTful Principles:

Adhere to RESTful design principles when designing your Web APIs, including resource-based URLs, HTTP verbs for CRUD operations, stateless communication, and hypermedia controls for navigation.

Use DTOs (Data Transfer Objects):

Use Data Transfer Objects (DTOs) to encapsulate data transferred between the client and server, ensuring a clear separation of concerns and minimizing coupling between the client and server.

Implement Input and Output Validation:

Validate input data using model annotations and validation attributes to ensure data integrity and prevent security vulnerabilities such as injection attacks and data tampering.

Implement Authentication and Authorization:

Secure your Web APIs by implementing authentication and authorization mechanisms such as JWT (JSON Web Tokens), OAuth, and role-based access control to protect sensitive resources and enforce access policies.

Follow RESTful Principles:

ASP.NET Core Web APIs offer a powerful and flexible platform for building modern, scalable, and interoperable web services. By understanding their fundamentals and best practices, developers can leverage the full potential of ASP.NET Core to create robust and reliable APIs that meet the evolving needs of today’s interconnected world. Whether you’re building a simple RESTful service or a complex microservices architecture, ASP.NET Core Web APIs provide the tools and capabilities you need to succeed in your API development journey.