diff --git a/src/Keycloak.Net/Common/Extensions/FlurlRequestExtensions.cs b/src/Keycloak.Net/Common/Extensions/FlurlRequestExtensions.cs
index daed9932..e963e3cd 100644
--- a/src/Keycloak.Net/Common/Extensions/FlurlRequestExtensions.cs
+++ b/src/Keycloak.Net/Common/Extensions/FlurlRequestExtensions.cs
@@ -11,16 +11,16 @@ public static class FlurlRequestExtensions
         private static async Task<string> GetAccessTokenAsync(string url, string realm, string userName, string password)
         {
             var result = await url
-				.AppendPathSegment($"/auth/realms/{realm}/protocol/openid-connect/token")
-				.WithHeader("Accept", "application/json")
-				.PostUrlEncodedAsync(new List<KeyValuePair<string, string>>
-				{
-					new KeyValuePair<string, string>("grant_type", "password"),
-					new KeyValuePair<string, string>("username", userName),
-					new KeyValuePair<string, string>("password", password),
-					new KeyValuePair<string, string>("client_id", "admin-cli")
-				})
-				.ReceiveJson().ConfigureAwait(false);
+                .AppendPathSegment($"/auth/realms/{realm}/protocol/openid-connect/token")
+                .WithHeader("Accept", "application/json")
+                .PostUrlEncodedAsync(new List<KeyValuePair<string, string>>
+                {
+                    new KeyValuePair<string, string>("grant_type", "password"),
+                    new KeyValuePair<string, string>("username", userName),
+                    new KeyValuePair<string, string>("password", password),
+                    new KeyValuePair<string, string>("client_id", "admin-cli")
+                })
+                .ReceiveJson().ConfigureAwait(false);
 
             string accessToken = result
                 .access_token.ToString();
@@ -30,15 +30,45 @@ private static async Task<string> GetAccessTokenAsync(string url, string realm,
 
         private static string GetAccessToken(string url, string realm, string userName, string password) => GetAccessTokenAsync(url, realm, userName, password).GetAwaiter().GetResult();
 
-        public static IFlurlRequest WithAuthentication(this IFlurlRequest request, Func<string> getToken, string url, string realm, string userName, string password)
+        private static async Task<string> GetAccessTokenAsync(string url, string realm, string clientSecret)
         {
+            var result = await url
+                .AppendPathSegment($"/auth/realms/{realm}/protocol/openid-connect/token")
+                .WithHeader("Content-Type", "application/x-www-form-urlencoded")
+                .PostUrlEncodedAsync(new List<KeyValuePair<string, string>>
+                {
+                    new KeyValuePair<string, string>("grant_type", "client_credentials"),
+                    new KeyValuePair<string, string>("client_secret", clientSecret),
+                    new KeyValuePair<string, string>("client_id", "admin-cli")
+                })
+                .ReceiveJson().ConfigureAwait(false);
+
+            string accessToken = result
+                .access_token.ToString();
+
+            return accessToken;
+        }
+
+        private static string GetAccessToken(string url, string realm, string clientSecret) => GetAccessTokenAsync(url, realm, clientSecret).GetAwaiter().GetResult();
+
+        public static IFlurlRequest WithAuthentication(this IFlurlRequest request, Func<string> getToken, string url, string realm, string userName, string password, string clientSecret)
+        {
+            string token = null;
+
             if (getToken != null)
             {
-                string token = getToken();
-                return request.WithOAuthBearerToken(token);
+                token = getToken();
+            }
+            else if (clientSecret != null)
+            {
+                token = GetAccessToken(url, realm, clientSecret);
+            }
+            else
+            {
+                token = GetAccessToken(url, realm, userName, password);
             }
 
-            return request.WithOAuthBearerToken(GetAccessToken(url, realm, userName, password));
+            return request.WithOAuthBearerToken(token);
         }
 
         public static IFlurlRequest WithForwardedHttpHeaders(this IFlurlRequest request, ForwardedHttpHeaders forwardedHeaders)
diff --git a/src/Keycloak.Net/KeycloakClient.cs b/src/Keycloak.Net/KeycloakClient.cs
index 5657d4c3..0e00371d 100755
--- a/src/Keycloak.Net/KeycloakClient.cs
+++ b/src/Keycloak.Net/KeycloakClient.cs
@@ -1,52 +1,59 @@
-using System;
-using Flurl;
-using Flurl.Http;
-using Flurl.Http.Configuration;
-using Keycloak.Net.Common.Extensions;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Serialization;
-
-namespace Keycloak.Net
-{
-    public partial class KeycloakClient
-    {
-        private ISerializer _serializer = new NewtonsoftJsonSerializer(new JsonSerializerSettings
-        {
-            ContractResolver = new CamelCasePropertyNamesContractResolver(),
-            NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore
-        });
-
-        private readonly Url _url;
-        private readonly string _userName;
-        private readonly string _password;
-        private readonly Func<string> _getToken;
-
-        private KeycloakClient(string url)
-        {
-            _url = url;
-        }
-
-        public KeycloakClient(string url, string userName, string password)
-            : this(url)
-        {
-            _userName = userName;
-            _password = password;
-        }
-
-        public KeycloakClient(string url, Func<string> getToken)
-            : this(url)
-        {
-            _getToken = getToken;
-        }
-
-        public void SetSerializer(ISerializer serializer)
+using System;
+using Flurl;
+using Flurl.Http;
+using Flurl.Http.Configuration;
+using Keycloak.Net.Common.Extensions;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Serialization;
+
+namespace Keycloak.Net
+{
+    public partial class KeycloakClient
+    {
+        private ISerializer _serializer = new NewtonsoftJsonSerializer(new JsonSerializerSettings
         {
-            _serializer = serializer ?? throw new ArgumentNullException(nameof(serializer));
-        }
-
-        private IFlurlRequest GetBaseUrl(string authenticationRealm) => new Url(_url)
-            .AppendPathSegment("/auth")
-            .ConfigureRequest(settings => settings.JsonSerializer = _serializer)
-            .WithAuthentication(_getToken, _url, authenticationRealm, _userName, _password);
-    }
-}
+            ContractResolver = new CamelCasePropertyNamesContractResolver(),
+            NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore
+        });
+
+        private readonly Url _url;
+        private readonly string _userName;
+        private readonly string _password;
+        private readonly string _clientSecret;
+        private readonly Func<string> _getToken;
+
+        private KeycloakClient(string url)
+        {
+            _url = url;
+        }
+
+        public KeycloakClient(string url, string userName, string password)
+            : this(url)
+        {
+            _userName = userName;
+            _password = password;
+        }
+
+        public KeycloakClient(string url, string clientSecret)
+            : this(url)
+        {
+            _clientSecret = clientSecret;
+        }
+
+        public KeycloakClient(string url, Func<string> getToken)
+            : this(url)
+        {
+            _getToken = getToken;
+        }
+
+        public void SetSerializer(ISerializer serializer)
+        {
+            _serializer = serializer ?? throw new ArgumentNullException(nameof(serializer));
+        }
+
+        private IFlurlRequest GetBaseUrl(string authenticationRealm) => new Url(_url)
+            .AppendPathSegment("/auth")
+            .ConfigureRequest(settings => settings.JsonSerializer = _serializer)
+            .WithAuthentication(_getToken, _url, authenticationRealm, _userName, _password, _clientSecret);
+    }
+}