🔧 Understanding API Versioning: A Simple Guide -Part 1 : Implementation using C#

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Mvc.Versioning" Version="5.0.0" />
  </ItemGroup>

</Project>

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllers();
        services.AddApiVersioning(config =>
        {
            // Specify the default API Version
            config.DefaultApiVersion = new Microsoft.AspNetCore.Mvc.ApiVersion(1, 0);
            config.AssumeDefaultVersionWhenUnspecified = true;
            config.ReportApiVersions = true;

            // Versioning strategy: URL path
            config.ApiVersionReader = new Microsoft.AspNetCore.Mvc.Versioning.UrlSegmentApiVersionReader();
        });
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseHttpsRedirection();
        app.UseRouting();
        app.UseAuthorization();
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
        });
    }
}

using Microsoft.AspNetCore.Mvc;

namespace VersioningExample.Controllers
{
    // v1 Controller
    [ApiController]
    [Route("api/v{version:apiVersion}/weather")]
    [ApiVersion("1.0")]
    public class WeatherV1Controller : ControllerBase
    {
        [HttpGet]
        public IActionResult Get()
        {
            var weatherData = new
            {
                temperature = 25,
                humidity = 60
            };
            return Ok(weatherData);
        }
    }

    // v2 Controller
    [ApiController]
    [Route("api/v{version:apiVersion}/weather")]
    [ApiVersion("2.0")]
    public class WeatherV2Controller : ControllerBase
    {
        [HttpGet]
        public IActionResult Get()
        {
            var weatherData = new
            {
                temp = 25,
                hum = 60,
                wind_speed = 10
            };
            return Ok(weatherData);
        }
    }
}

using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Hosting;

public class Program
{
    public static void Main(string[] args)
    {
        CreateHostBuilder(args).Build().Run();
    }

    public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
            });
}