Reading cookie using asp.net web api

I'm not sure which version of Asp.Net you are referring to but according to:

https://learn.microsoft.com/en-us/aspnet/web-api/overview/advanced/http-cookies

You can retrieve cookies using something like:

var userName = Request.Headers.GetCookies("userName").FirstOrDefault()?["userName"].Value;

In a web api 2 controller you will also need a reference to System.Net.Http.

If you want to use cookies in any action filters (authorization for example), please use the below code to access to them.

public override void OnAuthorization(HttpActionContext context)
{
    var cookie = context.Request.Headers.GetCookies("your-cookie-name").FirstOrDefault();
}

1.if you are want to get cookie value in service then you can use this:-

service Class

public class CookieService : ICookieService
 {
     private readonly IHttpContextAccessor _contextAccessor;

     public CookieService(IHttpContextAccessor contextAccessor)
     {
         _contextAccessor = contextAccessor;
     }
     public string GetCookieValue()
     {
         string cookieValue = _contextAccessor.HttpContext.Request.Cookies["your Cookie Name"];

         return cookieValue ?? string.Empty;
     }
 }

Interface:-

public class ICookieService
{
 string GetCookieValue();
}

and you should have to add inject dependency in you startup.cs class for IHttpContextAccessor

 Services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

2.if you want to get cookie value in controller then you can use this:-

var cookieValue = HttpContext.Request.Cookies["your cookie value"].FirstOrDefault()