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Version: 5.0

Configure Cookies

FluentHttpClient includes simple, focused extensions for attaching cookies to an HttpRequestBuilder. Cookies are stored internally on the builder and applied when the final HttpRequestMessage is constructed.

Use WithCookie when you want to attach exactly one cookie to the request.

var builder = client
    .UsingBase()
    .WithCookie("session", "abc123");
  • Throws if name is null, empty, or whitespace.
  • null values are converted to an empty string.
  • Existing cookies with the same name are overwritten.

Add Multiple Cookies​

Use WithCookies to attach multiple cookies in one call.

var cookies = new[]
{
    new KeyValuePair<string, string>("session", "abc123"),
    new KeyValuePair<string, string>("theme", "dark"),
};

var builder = client
    .UsingBase()
    .WithCookies(cookies);
  • Throws if the collection itself is null.
  • Throws if any cookie name is null, empty, or whitespace.
  • Adds or overwrites existing entries.
  • null values are stored as empty strings.
note

Unlike query parameters or headers, cookies do not support multiple values per name.

Behavior Notes​

  • Cookies are accumulated in HttpRequestBuilder.Cookies.
  • Assigning the same cookie name overwrites the previous value.
  • Cookies are applied to the final request using a standard Cookie header.
  • Whitespace-only names are treated as invalid.
  • Values are stored exactly as provided (aside from null becoming an empty string).

Quick Reference​

MethodPurpose
WithCookie(string, string)Adds or overwrites a single cookie.
WithCookies(IEnumerable<KeyValuePair<string,string>>)Add multiple cookies at once.