Version RESTful APIs with ASP.NET Core API Versioning

ASP.NET Core API Versioning support allows you to have multiple versions of an API coexist on the same server, allowing developers and clients to gradually migrate to newer versions of the API as they are released. In this page, we will discuss how to implement API versioning using ASP.NET Core.

Syntax

The syntax for implementing API versioning in ASP.NET Core is straightforward. To declare a version, you need to annotate your controller or endpoint with an attribute that specifies the version of the API it represents. Below is an example of the syntax:

services.AddApiVersioning(o =>
{
    o.ApiVersionReader = new QueryStringApiVersionReader("version");
    o.AssumeDefaultVersionWhenUnspecified = true;
    o.DefaultApiVersion = new ApiVersion(1, 0);
});

Example

The easiest way to implement API versioning is by adding a version number to the endpoint that you want to version. Here is an example of how to annotate a controller class with API version 1.0:

[ApiVersion("1.0")]
[Route("api/v{version:apiVersion}/[controller]")]
public class ProductsController : ControllerBase
{
    [HttpGet]
    public IEnumerable<string> Get()
    {
        return new string[] { "Product A", "Product B", "Product C" };
    }
}

To version an endpoint, simply include the version number in the URL for the endpoint.

Output

API versioning helps in incrementally releasing new features while maintaining backwards compatibility with existing versions of the API. Keeping the older and newer version of API together simplifies the process of migration and helps to support clients who may not be able to upgrade to the latest version of the API.

Explanation

Versioning is needed when you make an API update that is incompatible with the previous version, and clients that use the API will have to update their code accordingly. ASP.NET Core API versioning provides a simple and effective way to manage multiple versions of an API simultaneously.

Use

API versioning enables developers and product owners to add features incrementally in a complex system without breaking existing contracts with consumer software. APIs must evolve and support a newer, better operating systems, languages and other dependencies; API versioning is the way to handle such evolution.

Important Points

• API versioning allows for multiple versions of an API to coexist on the same server.
• The syntax for implementing API versioning in ASP.NET Core is straightforward.
• API versioning enables developers and product owners to add features incrementally in a complex system without breaking existing contracts with consumer software.

Summary

In this page, we discussed how to implement API versioning using ASP.NET Core. We covered the syntax, example, output, explanation, use, important points, and summary of API versioning. By implementing API versioning in your project, you can manage multiple versions of an API simultaneously, maintain backwards compatibility, and support clients who may not be able to upgrade to the latest version of the API.