diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8b35a7a..eba36e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,12 @@
 # Changelog
+## [v0.4.0](https://github.com/contentstack/contentstack-management-dotnet/tree/v0.4.0)
+ - Feat
+   - **MFA Support**: Added Multi-Factor Authentication (MFA) support for login operations
+     - Added `mfaSecret` parameter to `Login` and `LoginAsync` methods for TOTP generation
+     - Automatic TOTP token generation from Base32-encoded MFA secrets using Otp.NET library
+     - Comprehensive test coverage for MFA functionality including unit and integration tests
+     - Supports both explicit token and MFA secret-based authentication flows
+
 ## [v0.3.2](https://github.com/contentstack/contentstack-management-dotnet/tree/v0.3.2)
  - Fix
    - Added Test cases for the Release
diff --git a/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack001_LoginTest.cs b/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack001_LoginTest.cs
index c500203..cf5824e 100644
--- a/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack001_LoginTest.cs
+++ b/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack001_LoginTest.cs
@@ -175,5 +175,123 @@ public void Test007_Should_Return_Loggedin_User_With_Organizations_detail()
                 Assert.Fail(e.Message);
             }
         }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public void Test008_Should_Fail_Login_With_Invalid_MfaSecret()
+        {
+            ContentstackClient client = new ContentstackClient();
+            NetworkCredential credentials = new NetworkCredential("test_user", "test_password");
+            string invalidMfaSecret = "INVALID_BASE32_SECRET!@#";
+            
+            try
+            {
+                ContentstackResponse contentstackResponse = client.Login(credentials, null, invalidMfaSecret);
+                Assert.Fail("Expected exception for invalid MFA secret");
+            }
+            catch (ArgumentException)
+            {
+                // Expected exception for invalid Base32 encoding
+                Assert.IsTrue(true);
+            }
+            catch (Exception e)
+            {
+                Assert.Fail($"Unexpected exception type: {e.GetType().Name} - {e.Message}");
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public void Test009_Should_Generate_TOTP_Token_With_Valid_MfaSecret()
+        {
+            ContentstackClient client = new ContentstackClient();
+            NetworkCredential credentials = new NetworkCredential("test_user", "test_password");
+            string validMfaSecret = "JBSWY3DPEHPK3PXP"; // Valid Base32 test secret
+            
+            try
+            {
+                // This should fail due to invalid credentials, but should succeed in generating TOTP
+                ContentstackResponse contentstackResponse = client.Login(credentials, null, validMfaSecret);
+            }
+            catch (ContentstackErrorException errorException)
+            {
+                // Expected to fail due to invalid credentials, but we verify it processed the MFA secret
+                // The error should be about credentials, not about MFA secret format
+                Assert.AreEqual(HttpStatusCode.UnprocessableEntity, errorException.StatusCode);
+                Assert.IsTrue(errorException.Message.Contains("email or password") || 
+                             errorException.Message.Contains("credentials") ||
+                             errorException.Message.Contains("authentication"));
+            }
+            catch (ArgumentException)
+            {
+                Assert.Fail("Should not throw ArgumentException for valid MFA secret");
+            }
+            catch (Exception e)
+            {
+                Assert.Fail($"Unexpected exception type: {e.GetType().Name} - {e.Message}");
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public async System.Threading.Tasks.Task Test010_Should_Generate_TOTP_Token_With_Valid_MfaSecret_Async()
+        {
+            ContentstackClient client = new ContentstackClient();
+            NetworkCredential credentials = new NetworkCredential("test_user", "test_password");
+            string validMfaSecret = "JBSWY3DPEHPK3PXP"; // Valid Base32 test secret
+            
+            try
+            {
+                // This should fail due to invalid credentials, but should succeed in generating TOTP
+                ContentstackResponse contentstackResponse = await client.LoginAsync(credentials, null, validMfaSecret);
+            }
+            catch (ContentstackErrorException errorException)
+            {
+                // Expected to fail due to invalid credentials, but we verify it processed the MFA secret
+                // The error should be about credentials, not about MFA secret format
+                Assert.AreEqual(HttpStatusCode.UnprocessableEntity, errorException.StatusCode);
+                Assert.IsTrue(errorException.Message.Contains("email or password") || 
+                             errorException.Message.Contains("credentials") ||
+                             errorException.Message.Contains("authentication"));
+            }
+            catch (ArgumentException)
+            {
+                Assert.Fail("Should not throw ArgumentException for valid MFA secret");
+            }
+            catch (Exception e)
+            {
+                Assert.Fail($"Unexpected exception type: {e.GetType().Name} - {e.Message}");
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public void Test011_Should_Prefer_Explicit_Token_Over_MfaSecret()
+        {
+            ContentstackClient client = new ContentstackClient();
+            NetworkCredential credentials = new NetworkCredential("test_user", "test_password");
+            string validMfaSecret = "JBSWY3DPEHPK3PXP";
+            string explicitToken = "123456";
+            
+            try
+            {
+                // This should fail due to invalid credentials, but should use explicit token
+                ContentstackResponse contentstackResponse = client.Login(credentials, explicitToken, validMfaSecret);
+            }
+            catch (ContentstackErrorException errorException)
+            {
+                // Expected to fail due to invalid credentials
+                // The important thing is that it didn't throw an exception about MFA secret processing
+                Assert.AreEqual(HttpStatusCode.UnprocessableEntity, errorException.StatusCode);
+            }
+            catch (ArgumentException)
+            {
+                Assert.Fail("Should not throw ArgumentException when explicit token is provided");
+            }
+            catch (Exception e)
+            {
+                Assert.Fail($"Unexpected exception type: {e.GetType().Name} - {e.Message}");
+            }
+        }
     }
 }
diff --git a/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack016_VariantsTest.cs b/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack016_VariantsTest.cs
new file mode 100644
index 0000000..4d64f52
--- /dev/null
+++ b/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack016_VariantsTest.cs
@@ -0,0 +1,258 @@
+using System;
+using System.Threading.Tasks;
+using Contentstack.Management.Core.Models;
+using Contentstack.Management.Core.Tests.Model;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace Contentstack.Management.Core.Tests.IntegrationTest
+{
+    [TestClass]
+    public class Contentstack016_VariantsTest
+    {
+        private Stack _stack;
+
+        [TestInitialize]
+        public void Initialize()
+        {
+            StackResponse response = StackResponse.getStack(Contentstack.Client.serializer);
+            _stack = Contentstack.Client.Stack(response.Stack.APIKey);
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public async Task Test001_Should_Create_Variants()
+        {
+            try
+            {
+                VariantsModel variantsModel = new VariantsModel();
+                ContentstackResponse response = await _stack.Variants().CreateAsync(variantsModel);
+                Assert.AreEqual(System.Net.HttpStatusCode.Created, response.StatusCode);
+            }
+            catch (Exception e)
+            {
+                Assert.Fail(e.Message);
+            }
+        }
+
+        [TestMethod] 
+        [DoNotParallelize]
+        public async Task Test002_Should_Fetch_Variants_By_Uid()
+        {
+            try
+            {
+                // First create a variant to ensure we have something to fetch
+                VariantsModel variantsModel = new VariantsModel();
+                ContentstackResponse createResponse = await _stack.Variants().CreateAsync(variantsModel);
+                Assert.AreEqual(System.Net.HttpStatusCode.Created, createResponse.StatusCode);
+
+                // Extract UID from created variant
+                var createdVariant = createResponse.OpenJObjectResponse();
+                string variantUid = createdVariant["variant"]["uid"].ToString();
+
+                // Test fetching by UID
+                ContentstackResponse fetchResponse = await _stack.Variants(variantUid).FetchAsync();
+                Assert.IsTrue(fetchResponse.StatusCode == System.Net.HttpStatusCode.OK || 
+                             fetchResponse.StatusCode == System.Net.HttpStatusCode.NotFound);
+            }
+            catch (Exception e)
+            {
+                Assert.Fail(e.Message);
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public async Task Test003_Should_FetchByUid_Multiple_Variants()
+        {
+            try
+            {
+                // Create multiple variants first
+                VariantsModel variantsModel1 = new VariantsModel();
+                VariantsModel variantsModel2 = new VariantsModel();
+
+                ContentstackResponse createResponse1 = await _stack.Variants().CreateAsync(variantsModel1);
+                ContentstackResponse createResponse2 = await _stack.Variants().CreateAsync(variantsModel2);
+
+                Assert.AreEqual(System.Net.HttpStatusCode.Created, createResponse1.StatusCode);
+                Assert.AreEqual(System.Net.HttpStatusCode.Created, createResponse2.StatusCode);
+
+                // Extract UIDs from created variants
+                var createdVariant1 = createResponse1.OpenJObjectResponse();
+                var createdVariant2 = createResponse2.OpenJObjectResponse();
+                string variantUid1 = createdVariant1["variant"]["uid"].ToString();
+                string variantUid2 = createdVariant2["variant"]["uid"].ToString();
+
+                // Test fetching multiple variants by UIDs
+                string[] uids = { variantUid1, variantUid2 };
+                ContentstackResponse fetchResponse = await _stack.Variants().FetchByUidAsync(uids);
+                
+                Assert.IsTrue(fetchResponse.StatusCode == System.Net.HttpStatusCode.OK || 
+                             fetchResponse.StatusCode == System.Net.HttpStatusCode.NotFound);
+            }
+            catch (Exception e)
+            {
+                Assert.Fail(e.Message);
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public async Task Test004_Should_FetchByUid_Single_Variant()
+        {
+            try
+            {
+                // Create a variant first
+                VariantsModel variantsModel = new VariantsModel();
+                ContentstackResponse createResponse = await _stack.Variants().CreateAsync(variantsModel);
+                Assert.AreEqual(System.Net.HttpStatusCode.Created, createResponse.StatusCode);
+
+                // Extract UID from created variant
+                var createdVariant = createResponse.OpenJObjectResponse();
+                string variantUid = createdVariant["variant"]["uid"].ToString();
+
+                // Test fetching single variant using FetchByUid
+                string[] uids = { variantUid };
+                ContentstackResponse fetchResponse = await _stack.Variants().FetchByUidAsync(uids);
+                
+                Assert.IsTrue(fetchResponse.StatusCode == System.Net.HttpStatusCode.OK || 
+                             fetchResponse.StatusCode == System.Net.HttpStatusCode.NotFound);
+            }
+            catch (Exception e)
+            {
+                Assert.Fail(e.Message);
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public async Task Test005_Should_Handle_FetchByUid_With_Nonexistent_Uids()
+        {
+            try
+            {
+                // Test fetching with non-existent UIDs
+                string[] nonExistentUids = { "nonexistent_uid_1", "nonexistent_uid_2" };
+                ContentstackResponse fetchResponse = await _stack.Variants().FetchByUidAsync(nonExistentUids);
+                
+                // Should return 404 or empty result, not crash
+                Assert.IsTrue(fetchResponse.StatusCode == System.Net.HttpStatusCode.NotFound || 
+                             fetchResponse.StatusCode == System.Net.HttpStatusCode.OK);
+            }
+            catch (Exception e)
+            {
+                Assert.Fail(e.Message);
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public async Task Test006_Should_FetchByUid_Sync_Method()
+        {
+            try
+            {
+                // Create a variant first
+                VariantsModel variantsModel = new VariantsModel();
+                ContentstackResponse createResponse = _stack.Variants().Create(variantsModel);
+                Assert.AreEqual(System.Net.HttpStatusCode.Created, createResponse.StatusCode);
+
+                // Extract UID from created variant
+                var createdVariant = createResponse.OpenJObjectResponse();
+                string variantUid = createdVariant["variant"]["uid"].ToString();
+
+                // Test synchronous FetchByUid
+                string[] uids = { variantUid };
+                ContentstackResponse fetchResponse = _stack.Variants().FetchByUid(uids);
+                
+                Assert.IsTrue(fetchResponse.StatusCode == System.Net.HttpStatusCode.OK || 
+                             fetchResponse.StatusCode == System.Net.HttpStatusCode.NotFound);
+            }
+            catch (Exception e)
+            {
+                Assert.Fail(e.Message);
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public async Task Test007_Should_Delete_Variant()
+        {
+            try
+            {
+                // Create a variant first
+                VariantsModel variantsModel = new VariantsModel();
+                ContentstackResponse createResponse = await _stack.Variants().CreateAsync(variantsModel);
+                Assert.AreEqual(System.Net.HttpStatusCode.Created, createResponse.StatusCode);
+
+                // Extract UID from created variant
+                var createdVariant = createResponse.OpenJObjectResponse();
+                string variantUid = createdVariant["variant"]["uid"].ToString();
+
+                // Test deleting the variant
+                ContentstackResponse deleteResponse = await _stack.Variants(variantUid).DeleteAsync();
+                Assert.IsTrue(deleteResponse.StatusCode == System.Net.HttpStatusCode.OK || 
+                             deleteResponse.StatusCode == System.Net.HttpStatusCode.NoContent ||
+                             deleteResponse.StatusCode == System.Net.HttpStatusCode.NotFound);
+            }
+            catch (Exception e)
+            {
+                Assert.Fail(e.Message);
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public void Test008_Should_Validate_FetchByUid_Parameters()
+        {
+            try
+            {
+                // Test with null UIDs
+                Assert.ThrowsException<ArgumentException>(() => _stack.Variants().FetchByUid(null));
+
+                // Test with empty UIDs array
+                string[] emptyUids = new string[0];
+                Assert.ThrowsException<ArgumentException>(() => _stack.Variants().FetchByUid(emptyUids));
+            }
+            catch (Exception e)
+            {
+                Assert.Fail(e.Message);
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public async Task Test009_Should_Validate_FetchByUidAsync_Parameters()
+        {
+            try
+            {
+                // Test with null UIDs
+                await Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Variants().FetchByUidAsync(null));
+
+                // Test with empty UIDs array
+                string[] emptyUids = new string[0];
+                await Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Variants().FetchByUidAsync(emptyUids));
+            }
+            catch (Exception e)
+            {
+                Assert.Fail(e.Message);
+            }
+        }
+
+        [TestMethod]
+        [DoNotParallelize]
+        public void Test010_Should_Validate_Instance_With_Uid_Cannot_Use_FetchByUid()
+        {
+            try
+            {
+                // Test that an instance with UID cannot call FetchByUid
+                string instanceUid = "some_uid";
+                string[] uids = { "uid1", "uid2" };
+                
+                Assert.ThrowsException<InvalidOperationException>(() => 
+                    _stack.Variants(instanceUid).FetchByUid(uids));
+            }
+            catch (Exception e)
+            {
+                Assert.Fail(e.Message);
+            }
+        }
+    }
+}
diff --git a/Contentstack.Management.Core.Unit.Tests/Core/Services/User/LoginServiceTest.cs b/Contentstack.Management.Core.Unit.Tests/Core/Services/User/LoginServiceTest.cs
index 2f0f946..ed7dfdd 100644
--- a/Contentstack.Management.Core.Unit.Tests/Core/Services/User/LoginServiceTest.cs
+++ b/Contentstack.Management.Core.Unit.Tests/Core/Services/User/LoginServiceTest.cs
@@ -50,6 +50,107 @@ public void Should_Allow_Credentials_With_Token()
             Assert.AreEqual("{\"user\":{\"email\":\"name\",\"password\":\"password\",\"tfa_token\":\"token\"}}", Encoding.Default.GetString(loginService.ByteContent));
         }
 
+        [TestMethod]
+        public void Should_Allow_Credentials_With_MfaSecret()
+        {
+
+            string testMfaSecret = "JBSWY3DPEHPK3PXP"; // Base32 encoded "Hello!"
+            var loginService = new LoginService(serializer, credentials, null, testMfaSecret);
+            loginService.ContentBody();
+
+            Assert.IsNotNull(loginService);
+            var contentString = Encoding.Default.GetString(loginService.ByteContent);
+            
+            Assert.IsTrue(contentString.Contains("\"email\":\"name\""));
+            Assert.IsTrue(contentString.Contains("\"password\":\"password\""));
+            Assert.IsTrue(contentString.Contains("\"tfa_token\":"));
+            
+            // Verify the tfa_token is not null or empty in the JSON
+            Assert.IsFalse(contentString.Contains("\"tfa_token\":null"));
+            Assert.IsFalse(contentString.Contains("\"tfa_token\":\"\""));
+        }
+
+        [TestMethod]
+        public void Should_Generate_TOTP_Token_When_MfaSecret_Provided()
+        {
+            string testMfaSecret = "JBSWY3DPEHPK3PXP"; // Base32 encoded "Hello!"
+            var loginService1 = new LoginService(serializer, credentials, null, testMfaSecret);
+            var loginService2 = new LoginService(serializer, credentials, null, testMfaSecret);
+            
+            loginService1.ContentBody();
+            loginService2.ContentBody();
+
+            var content1 = Encoding.Default.GetString(loginService1.ByteContent);
+            var content2 = Encoding.Default.GetString(loginService2.ByteContent);
+
+            // Both should contain tfa_token
+            Assert.IsTrue(content1.Contains("\"tfa_token\":"));
+            Assert.IsTrue(content2.Contains("\"tfa_token\":"));
+            
+            // Extract the tokens for comparison (tokens should be 6 digits)
+            var token1Match = System.Text.RegularExpressions.Regex.Match(content1, "\"tfa_token\":\"(\\d{6})\"");
+            var token2Match = System.Text.RegularExpressions.Regex.Match(content2, "\"tfa_token\":\"(\\d{6})\"");
+            
+            Assert.IsTrue(token1Match.Success);
+            Assert.IsTrue(token2Match.Success);
+            
+            // Tokens should be valid 6-digit numbers
+            Assert.AreEqual(6, token1Match.Groups[1].Value.Length);
+            Assert.AreEqual(6, token2Match.Groups[1].Value.Length);
+        }
+
+        [TestMethod]
+        public void Should_Prefer_Explicit_Token_Over_MfaSecret()
+        {
+            string testMfaSecret = "JBSWY3DPEHPK3PXP";
+            // file deepcode ignore NoHardcodedCredentials/test: random test token
+            string explicitToken = "123456";
+            
+            var loginService = new LoginService(serializer, credentials, explicitToken, testMfaSecret);
+            loginService.ContentBody();
+
+            var contentString = Encoding.Default.GetString(loginService.ByteContent);
+            
+            // Should use the explicit token, not generate one from MFA secret
+            Assert.IsTrue(contentString.Contains("\"tfa_token\":\"123456\""));
+        }
+
+        [TestMethod]
+        [ExpectedException(typeof(ArgumentException))]
+        public void Should_Throw_Exception_For_Invalid_Base32_MfaSecret()
+        {
+            // Invalid Base32 secret (contains invalid characters)
+            string invalidMfaSecret = "INVALID_BASE32_123!@#";
+            
+            var loginService = new LoginService(serializer, credentials, null, invalidMfaSecret);
+        }
+
+        [TestMethod]
+        public void Should_Not_Generate_Token_When_MfaSecret_Is_Empty()
+        {
+            var loginService = new LoginService(serializer, credentials, null, "");
+            loginService.ContentBody();
+
+            var contentString = Encoding.Default.GetString(loginService.ByteContent);
+            
+            // Should not contain tfa_token when MFA secret is empty
+            Assert.IsFalse(contentString.Contains("\"tfa_token\":"));
+            Assert.AreEqual("{\"user\":{\"email\":\"name\",\"password\":\"password\"}}", contentString);
+        }
+
+        [TestMethod]
+        public void Should_Not_Generate_Token_When_MfaSecret_Is_Null()
+        {
+            var loginService = new LoginService(serializer, credentials, null, null);
+            loginService.ContentBody();
+
+            var contentString = Encoding.Default.GetString(loginService.ByteContent);
+            
+            // Should not contain tfa_token when MFA secret is null
+            Assert.IsFalse(contentString.Contains("\"tfa_token\":"));
+            Assert.AreEqual("{\"user\":{\"email\":\"name\",\"password\":\"password\"}}", contentString);
+        }
+
         [TestMethod]
         public void Should_Override_Authtoken_To_ContentstackOptions_On_Success()
         {
diff --git a/Contentstack.Management.Core.Unit.Tests/Models/VariantsTest.cs b/Contentstack.Management.Core.Unit.Tests/Models/VariantsTest.cs
new file mode 100644
index 0000000..9dcfc95
--- /dev/null
+++ b/Contentstack.Management.Core.Unit.Tests/Models/VariantsTest.cs
@@ -0,0 +1,258 @@
+using System;
+using System.Threading.Tasks;
+using AutoFixture;
+using Contentstack.Management.Core.Models;
+using Contentstack.Management.Core.Queryable;
+using Contentstack.Management.Core.Unit.Tests.Mokes;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace Contentstack.Management.Core.Unit.Tests.Models
+{
+    [TestClass]
+    public class VariantsTest
+    {
+        private Stack _stack;
+        private readonly IFixture _fixture = new Fixture();
+        private ContentstackResponse _contentstackResponse;
+        private VariantsModel _variantsModel = new VariantsModel();
+
+        [TestInitialize]
+        public void Initialize()
+        {
+            var client = new ContentstackClient();
+            _contentstackResponse = MockResponse.CreateContentstackResponse("MockResponse.txt");
+            client.ContentstackPipeline.ReplaceHandler(new MockHttpHandler(_contentstackResponse));
+            client.contentstackOptions.Authtoken = _fixture.Create<string>();
+            _stack = new Stack(client, _fixture.Create<string>());
+        }
+
+        #region Initialize Tests
+
+        [TestMethod]
+        public void Initialize_Variants_Without_Uid()
+        {
+            Variants variants = new Variants(_stack, null);
+
+            Assert.IsNull(variants.Uid);
+            Assert.AreEqual("/variants", variants.resourcePath);
+            Assert.ThrowsException<InvalidOperationException>(() => variants.Fetch());
+            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => variants.FetchAsync());
+            Assert.ThrowsException<InvalidOperationException>(() => variants.Delete());
+            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => variants.DeleteAsync());
+        }
+
+        [TestMethod]
+        public void Initialize_Variants_With_Uid()
+        {
+            string uid = _fixture.Create<string>();
+            Variants variants = new Variants(_stack, uid);
+
+            Assert.AreEqual(uid, variants.Uid);
+            Assert.AreEqual($"/variants/{uid}", variants.resourcePath);
+            Assert.ThrowsException<InvalidOperationException>(() => variants.Create(_variantsModel));
+            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => variants.CreateAsync(_variantsModel));
+            Assert.ThrowsException<InvalidOperationException>(() => variants.FetchByUid(new string[] { "uid1", "uid2" }));
+            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => variants.FetchByUidAsync(new string[] { "uid1", "uid2" }));
+        }
+
+        #endregion
+
+        #region Create Tests
+
+        [TestMethod]
+        public void Should_Create_Variants()
+        {
+            ContentstackResponse response = _stack.Variants().Create(_variantsModel);
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        [TestMethod]
+        public async Task Should_Create_Variants_Async()
+        {
+            ContentstackResponse response = await _stack.Variants().CreateAsync(_variantsModel);
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        #endregion
+
+        #region Fetch Tests
+
+        [TestMethod]
+        public void Should_Fetch_Variants()
+        {
+            ContentstackResponse response = _stack.Variants(_fixture.Create<string>()).Fetch();
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        [TestMethod]
+        public async Task Should_Fetch_Variants_Async()
+        {
+            ContentstackResponse response = await _stack.Variants(_fixture.Create<string>()).FetchAsync();
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        [TestMethod]
+        public void Should_Fetch_Variants_With_Parameters()
+        {
+            ParameterCollection collection = new ParameterCollection();
+            collection.Add("include_count", true);
+
+            ContentstackResponse response = _stack.Variants(_fixture.Create<string>()).Fetch(collection);
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        [TestMethod]
+        public async Task Should_Fetch_Variants_With_Parameters_Async()
+        {
+            ParameterCollection collection = new ParameterCollection();
+            collection.Add("include_count", true);
+
+            ContentstackResponse response = await _stack.Variants(_fixture.Create<string>()).FetchAsync(collection);
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        #endregion
+
+        #region FetchByUid Tests
+
+        [TestMethod]
+        public void Should_FetchByUid_Variants()
+        {
+            string[] uids = { _fixture.Create<string>(), _fixture.Create<string>(), _fixture.Create<string>() };
+            ContentstackResponse response = _stack.Variants().FetchByUid(uids);
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        [TestMethod]
+        public async Task Should_FetchByUid_Variants_Async()
+        {
+            string[] uids = { _fixture.Create<string>(), _fixture.Create<string>(), _fixture.Create<string>() };
+            ContentstackResponse response = await _stack.Variants().FetchByUidAsync(uids);
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        [TestMethod]
+        public void Should_Throw_Exception_When_FetchByUid_Called_With_Null_Uids()
+        {
+            Assert.ThrowsException<ArgumentException>(() => _stack.Variants().FetchByUid(null));
+        }
+
+        [TestMethod]
+        public async Task Should_Throw_Exception_When_FetchByUidAsync_Called_With_Null_Uids()
+        {
+            await Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Variants().FetchByUidAsync(null));
+        }
+
+        [TestMethod]
+        public void Should_Throw_Exception_When_FetchByUid_Called_With_Empty_Uids()
+        {
+            string[] emptyUids = new string[0];
+            Assert.ThrowsException<ArgumentException>(() => _stack.Variants().FetchByUid(emptyUids));
+        }
+
+        [TestMethod]
+        public async Task Should_Throw_Exception_When_FetchByUidAsync_Called_With_Empty_Uids()
+        {
+            string[] emptyUids = new string[0];
+            await Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Variants().FetchByUidAsync(emptyUids));
+        }
+
+        [TestMethod]
+        public void Should_Throw_Exception_When_FetchByUid_Called_On_Instance_With_Uid()
+        {
+            string[] uids = { _fixture.Create<string>(), _fixture.Create<string>() };
+            Assert.ThrowsException<InvalidOperationException>(() => _stack.Variants(_fixture.Create<string>()).FetchByUid(uids));
+        }
+
+        [TestMethod]
+        public async Task Should_Throw_Exception_When_FetchByUidAsync_Called_On_Instance_With_Uid()
+        {
+            string[] uids = { _fixture.Create<string>(), _fixture.Create<string>() };
+            await Assert.ThrowsExceptionAsync<InvalidOperationException>(() => _stack.Variants(_fixture.Create<string>()).FetchByUidAsync(uids));
+        }
+
+        [TestMethod]
+        public void Should_FetchByUid_Single_Uid()
+        {
+            string[] uids = { _fixture.Create<string>() };
+            ContentstackResponse response = _stack.Variants().FetchByUid(uids);
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        [TestMethod]
+        public async Task Should_FetchByUid_Single_Uid_Async()
+        {
+            string[] uids = { _fixture.Create<string>() };
+            ContentstackResponse response = await _stack.Variants().FetchByUidAsync(uids);
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        #endregion
+
+        #region Delete Tests
+
+        [TestMethod]
+        public void Should_Delete_Variants()
+        {
+            ContentstackResponse response = _stack.Variants(_fixture.Create<string>()).Delete();
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        [TestMethod]
+        public async Task Should_Delete_Variants_Async()
+        {
+            ContentstackResponse response = await _stack.Variants(_fixture.Create<string>()).DeleteAsync();
+
+            Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
+            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+        }
+
+        #endregion
+
+        #region Validation Tests
+
+        [TestMethod]
+        public void Should_Throw_Exception_When_APIKey_Is_Null()
+        {
+            var client = new ContentstackClient();
+            client.contentstackOptions.Authtoken = _fixture.Create<string>();
+            var stackWithNullAPIKey = new Stack(client, null);
+
+            Assert.ThrowsException<InvalidOperationException>(() => new Variants(stackWithNullAPIKey));
+        }
+
+        [TestMethod]
+        public void Should_Throw_Exception_When_APIKey_Is_Empty()
+        {
+            var client = new ContentstackClient();
+            client.contentstackOptions.Authtoken = _fixture.Create<string>();
+            var stackWithEmptyAPIKey = new Stack(client, "");
+
+            Assert.ThrowsException<InvalidOperationException>(() => new Variants(stackWithEmptyAPIKey));
+        }
+
+        #endregion
+    }
+}
diff --git a/Contentstack.Management.Core/ContentstackClient.cs b/Contentstack.Management.Core/ContentstackClient.cs
index ddbcc25..03904a2 100644
--- a/Contentstack.Management.Core/ContentstackClient.cs
+++ b/Contentstack.Management.Core/ContentstackClient.cs
@@ -334,6 +334,7 @@ public Stack Stack(string apiKey = null, string managementToken = null, string b
         /// </summary>
         /// <param name="credentials">User credentials for login.</param>
         /// <param name="token">The optional 2FA token.</param>
+        /// <param name="mfaSecret">The optional MFA Secret for 2FA token.</param>
         /// <example>
         /// <pre><code>
         /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
@@ -342,10 +343,10 @@ public Stack Stack(string apiKey = null, string managementToken = null, string b
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse" /></returns>
-        public ContentstackResponse Login(ICredentials credentials, string token = null)
+        public ContentstackResponse Login(ICredentials credentials, string token = null, string mfaSecret = null)
         {
             ThrowIfAlreadyLoggedIn();
-            LoginService Login = new LoginService(serializer, credentials, token);
+            LoginService Login = new LoginService(serializer, credentials, token, mfaSecret);
 
             return InvokeSync(Login);
         }
@@ -355,6 +356,7 @@ public ContentstackResponse Login(ICredentials credentials, string token = null)
         /// </summary>
         /// <param name="credentials">User credentials for login.</param>
         /// <param name="token">The optional 2FA token.</param>
+        /// <param name="mfaSecret">The optional MFA Secret for 2FA token.</param>
         /// <example>
         /// <pre><code>
         /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
@@ -363,10 +365,10 @@ public ContentstackResponse Login(ICredentials credentials, string token = null)
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public Task<ContentstackResponse> LoginAsync(ICredentials credentials, string token = null)
+        public Task<ContentstackResponse> LoginAsync(ICredentials credentials, string token = null, string mfaSecret = null)
         {
             ThrowIfAlreadyLoggedIn();
-            LoginService Login = new LoginService(serializer, credentials, token);
+            LoginService Login = new LoginService(serializer, credentials, token, mfaSecret);
 
             return InvokeAsync<LoginService, ContentstackResponse>(Login);
         }
diff --git a/Contentstack.Management.Core/Models/Stack.cs b/Contentstack.Management.Core/Models/Stack.cs
index d876e4a..90a14ac 100644
--- a/Contentstack.Management.Core/Models/Stack.cs
+++ b/Contentstack.Management.Core/Models/Stack.cs
@@ -4,7 +4,6 @@
 using Contentstack.Management.Core.Queryable;
 using Contentstack.Management.Core.Services.Stack;
 using Contentstack.Management.Core.Utils;
-using Contentstack.Management.Core.Models;
 using Contentstack.Management.Core.Models.Token;
 
 namespace Contentstack.Management.Core.Models
@@ -623,7 +622,7 @@ public ContentType ContentType(string uid = null)
             return new ContentType(this, uid);
         }
         /// <summary>
-        /// <see cref="Models.Asset"/> efer to all the media files (images, videos, PDFs, audio files, and so on) uploaded in your Contentstack repository for future use. 
+        /// <see cref="Models.Asset"/> refer to all the media files (images, videos, PDFs, audio files, and so on) uploaded in your Contentstack repository for future use. 
         /// </summary>
         /// <param name="uid">Optional asset uid.</param>
         /// <example>
@@ -763,7 +762,7 @@ public ManagementToken ManagementTokens(string uid = null)
         }
 
         /// <summary>
-        /// A <see cref="Models.Role" /> collection of permissions that will be applicable to all the users who are assigned this role.
+        /// A <see cref="Models.Role" /> is a collection of permissions that will be applicable to all the users who are assigned this role.
         /// </summary>
         /// <param name="uid">Optional, role uid.</param>
         /// <example>
@@ -773,7 +772,7 @@ public ManagementToken ManagementTokens(string uid = null)
         /// ContentstackResponse contentstackResponse = stack.Role("<ROLE_UID>").Fetch();
         /// </code></pre>
         /// </example>
-        /// <returns>The <see cref="Models.Release" /></returns>
+        /// <returns>The <see cref="Models.Role" /></returns>
         public Role Role(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -844,9 +843,9 @@ public PublishQueue PublishQueue(string uid = null)
             return new PublishQueue(this, uid);
         }
         /// <summary>
-        /// A <see cref="Models.Webhook" /> a mechanism that sends real-time information to any third-party app or service to keep your application in sync with your Contentstack account. 
+        /// A <see cref="Models.Webhook" /> is a mechanism that sends real-time information to any third-party app or service to keep your application in sync with your Contentstack account. 
         /// </summary>
-        /// <param name="uid">Optional, webhook uid uid.</param>
+        /// <param name="uid">Optional, webhook uid.</param>
         /// <example>
         /// <pre><code>
         /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
@@ -854,7 +853,7 @@ public PublishQueue PublishQueue(string uid = null)
         /// ContentstackResponse contentstackResponse = stack.Webhook("<WEBHOOK_UID>").Fetch();
         /// </code></pre>
         /// </example>
-        /// <returns>The <see cref="Models.AuditLog" /></returns>
+        /// <returns>The <see cref="Models.Webhook" /></returns>
         public Webhook Webhook(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -912,6 +911,26 @@ public BulkOperation BulkOperation()
 
             return new BulkOperation(this);
         }
+
+        /// <summary>
+        /// A <see cref="Models.Variants" /> represents different versions or variations of content entries that allow you to create and manage multiple variants of the same content.
+        /// </summary>
+        /// <param name="uid">Optional, variant uid.</param>
+        /// <example>
+        /// <pre><code>
+        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
+        /// Stack stack = client.Stack("<API_KEY>");
+        /// ContentstackResponse contentstackResponse = stack.Variants("<VARIANT_UID>").Fetch();
+        /// </code></pre>
+        /// </example>
+        /// <returns>The <see cref="Models.Variants"/></returns>
+        public Variants Variants(string uid = null)
+        {
+            ThrowIfNotLoggedIn();
+            ThrowIfAPIKeyEmpty();
+
+            return new Variants(this, uid);
+        }
         #endregion
 
         #region Throw Error
diff --git a/Contentstack.Management.Core/Models/Variants.cs b/Contentstack.Management.Core/Models/Variants.cs
new file mode 100644
index 0000000..b9afa58
--- /dev/null
+++ b/Contentstack.Management.Core/Models/Variants.cs
@@ -0,0 +1,226 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using Contentstack.Management.Core.Queryable;
+using Contentstack.Management.Core.Services.Models;
+using Contentstack.Management.Core.Abstractions;
+
+namespace Contentstack.Management.Core.Models
+{
+    public class Variants
+    {
+        internal Stack stack;
+        public string Uid { get; set; }
+
+        internal string resourcePath;
+
+        internal Variants(Stack stack, string uid = null)
+        {
+            stack.ThrowIfAPIKeyEmpty();
+
+            this.stack = stack;
+            Uid = uid;
+            resourcePath = uid == null ? "/variants" : $"/variants/{uid}";
+        }
+
+        /// <summary>
+        /// The Delete call is used to delete a specific variant.
+        /// </summary>
+        /// <example>
+        /// <pre><code>
+        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
+        /// ContentstackResponse contentstackResponse = client.Stack("<API_KEY>").Variants("<VARIANT_UID>").Delete();
+        /// </code></pre>
+        /// </example>
+        /// <returns>The <see cref="ContentstackResponse"/> containing the deletion result.</returns>
+        public ContentstackResponse Delete()
+        {
+            stack.ThrowIfNotLoggedIn();
+            ThrowIfUidEmpty();
+
+            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath, "DELETE");
+            return stack.client.InvokeSync(service);
+        }
+
+        /// <summary>
+        /// The DeleteAsync call is used to asynchronously delete a specific variant.
+        /// </summary>
+        /// <example>
+        /// <pre><code>
+        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
+        /// ContentstackResponse contentstackResponse = await client.Stack("<API_KEY>").Variants("<VARIANT_UID>").DeleteAsync();
+        /// </code></pre>
+        /// </example>
+        /// <returns>The Task containing <see cref="ContentstackResponse"/> with the deletion result.</returns>
+        public Task<ContentstackResponse> DeleteAsync()
+        {
+            stack.ThrowIfNotLoggedIn();
+            ThrowIfUidEmpty();
+
+            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath, "DELETE");
+            return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service, true);
+        }
+
+        /// <summary>
+        /// The Fetch call retrieves a specific variant by UID.
+        /// </summary>
+        /// <param name="collection">Optional query parameters.</param>
+        /// <example>
+        /// <pre><code>
+        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
+        /// ContentstackResponse contentstackResponse = client.Stack("<API_KEY>").Variants("<VARIANT_UID>").Fetch();
+        /// </code></pre>
+        /// </example>
+        /// <returns>The <see cref="ContentstackResponse"/> containing the variant data.</returns>
+        public ContentstackResponse Fetch(ParameterCollection collection = null)
+        {
+            stack.ThrowIfNotLoggedIn();
+            ThrowIfUidEmpty();
+
+            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath, collection: collection);
+            return stack.client.InvokeSync(service);
+        }
+
+        /// <summary>
+        /// The FetchAsync call asynchronously retrieves a specific variant by UID.
+        /// </summary>
+        /// <param name="collection">Optional query parameters.</param>
+        /// <example>
+        /// <pre><code>
+        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
+        /// ContentstackResponse contentstackResponse = await client.Stack("<API_KEY>").Variants("<VARIANT_UID>").FetchAsync();
+        /// </code></pre>
+        /// </example>
+        /// <returns>The Task containing <see cref="ContentstackResponse"/> with the variant data.</returns>
+        public Task<ContentstackResponse> FetchAsync(ParameterCollection collection = null)
+        {
+            stack.ThrowIfNotLoggedIn();
+            ThrowIfUidEmpty();
+
+            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath, collection: collection);
+            return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
+        }
+        
+        /// <summary>
+        /// The Create call is used to create an entry variant in the stack.
+        /// </summary>
+        /// <param name="model">The <see cref="VariantsModel"/> containing variant details.</param>
+        /// <example>
+        /// <pre><code>
+        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
+        /// VariantsModel model = new VariantsModel(); 
+        /// ContentstackResponse contentstackResponse = client.Stack("<API_KEY>").Variants().Create(model);
+        /// </code></pre>
+        /// </example>
+        /// <returns>The <see cref="ContentstackResponse"/> containing the created variant data.</returns>
+        public ContentstackResponse Create(VariantsModel model)
+        {
+            ThrowIfUidNotEmpty();
+
+            var service = new CreateUpdateService<VariantsModel>(stack.client.serializer, stack, resourcePath, model, "entry");
+            return stack.client.InvokeSync(service);
+        }
+
+        /// <summary>
+        /// The CreateAsync call is used to asynchronously create an entry variant in the stack.
+        /// </summary>
+        /// <param name="model">The <see cref="VariantsModel"/> containing variant details.</param>
+        /// <example>
+        /// <pre><code>
+        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
+        /// VariantsModel model = new VariantsModel();
+        /// ContentstackResponse contentstackResponse = await client.Stack("<API_KEY>").Variants().CreateAsync(model);
+        /// </code></pre>
+        /// </example>
+        /// <returns>The Task containing <see cref="ContentstackResponse"/> with the created variant data.</returns>
+        public Task<ContentstackResponse> CreateAsync(VariantsModel model)
+        {
+            ThrowIfUidNotEmpty();
+            stack.ThrowIfNotLoggedIn();
+
+            var service = new CreateUpdateService<VariantsModel>(stack.client.serializer, stack, resourcePath, model, "entry");
+            return stack.client.InvokeAsync<CreateUpdateService<VariantsModel>, ContentstackResponse>(service);
+        }
+
+        /// <summary>
+        /// The FetchByUid call retrieves multiple variants by passing an array of their UIDs.
+        /// This method allows you to fetch multiple variants in a single API call.
+        /// </summary>
+        /// <param name="uids">Array of variant UIDs to fetch. Cannot be null or empty.</param>
+        /// <example>
+        /// <pre><code>
+        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
+        /// string[] variantUids = {"bltvariant123", "bltvariant456", "bltvariant789"};
+        /// ContentstackResponse contentstackResponse = client.Stack("<API_KEY>").Variants().FetchByUid(variantUids);
+        /// </code></pre>
+        /// </example>
+        /// <returns>The <see cref="ContentstackResponse"/> containing the requested variants data.</returns>
+        public ContentstackResponse FetchByUid(string[] uids)
+        {
+            stack.ThrowIfNotLoggedIn();
+            ThrowIfUidNotEmpty();
+
+            if (uids == null || uids.Length == 0)
+            {
+                throw new ArgumentException("UIDs array cannot be null or empty.", nameof(uids));
+            }
+
+            var collection = new ParameterCollection();
+            collection.Add("uid", uids.ToList());
+
+            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath, collection: collection);
+            return stack.client.InvokeSync(service);
+        }
+
+        /// <summary>
+        /// The FetchByUidAsync call asynchronously retrieves multiple variants by passing an array of their UIDs.
+        /// This method allows you to fetch multiple variants in a single API call asynchronously.
+        /// </summary>
+        /// <param name="uids">Array of variant UIDs to fetch. Cannot be null or empty.</param>
+        /// <example>
+        /// <pre><code>
+        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
+        /// string[] variantUids = {"bltvariant123", "bltvariant456", "bltvariant789"};
+        /// ContentstackResponse contentstackResponse = await client.Stack("<API_KEY>").Variants().FetchByUidAsync(variantUids);
+        /// </code></pre>
+        /// </example>
+        /// <returns>The Task containing <see cref="ContentstackResponse"/> with the requested variants data.</returns>
+        public Task<ContentstackResponse> FetchByUidAsync(string[] uids)
+        {
+            stack.ThrowIfNotLoggedIn();
+            ThrowIfUidNotEmpty();
+
+            if (uids == null || uids.Length == 0)
+            {
+                throw new ArgumentException("UIDs array cannot be null or empty.", nameof(uids));
+            }
+
+            var collection = new ParameterCollection();
+            collection.Add("uid", uids.ToList());
+
+            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath, collection: collection);
+            return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
+        }
+
+        #region Internal Validation
+
+        /// <summary>Validates no UID is set for collection operations.</summary>
+        internal void ThrowIfUidNotEmpty()
+        {
+            if (!string.IsNullOrEmpty(this.Uid))
+            {
+                throw new InvalidOperationException("Operation not allowed.");
+            }
+        }
+
+        /// <summary>Validates UID is set for specific variant operations.</summary>
+        internal void ThrowIfUidEmpty()
+        {
+            if (string.IsNullOrEmpty(this.Uid))
+            {
+                throw new InvalidOperationException("Uid can not be empty.");
+            }
+        }
+        #endregion
+    }
+}
diff --git a/Contentstack.Management.Core/Models/VariantsModel.cs b/Contentstack.Management.Core/Models/VariantsModel.cs
new file mode 100644
index 0000000..0abae0c
--- /dev/null
+++ b/Contentstack.Management.Core/Models/VariantsModel.cs
@@ -0,0 +1,12 @@
+using System;
+using Newtonsoft.Json;
+
+namespace Contentstack.Management.Core.Models
+{
+    [JsonObject(ItemNullValueHandling = NullValueHandling.Ignore)]
+    public class VariantsModel
+    {
+        [JsonProperty(propertyName: "title")]
+        string Title { get; set; }
+    }
+}
diff --git a/Contentstack.Management.Core/Services/User/LoginService.cs b/Contentstack.Management.Core/Services/User/LoginService.cs
index 5c5c180..9dbaf05 100644
--- a/Contentstack.Management.Core/Services/User/LoginService.cs
+++ b/Contentstack.Management.Core/Services/User/LoginService.cs
@@ -4,6 +4,7 @@
 using Newtonsoft.Json;
 using System.Globalization;
 using Newtonsoft.Json.Linq;
+using OtpNet;
 using Contentstack.Management.Core.Http;
 
 namespace Contentstack.Management.Core.Services.User
@@ -16,7 +17,7 @@ internal class LoginService : ContentstackService
         #endregion
 
         #region Constructor
-        internal LoginService(JsonSerializer serializer, ICredentials credentials, string token = null): base(serializer)
+        internal LoginService(JsonSerializer serializer, ICredentials credentials, string token = null, string mfaSecret = null): base(serializer)
         {
             this.HttpMethod = "POST";
             this.ResourcePath = "user-session";
@@ -27,7 +28,18 @@ internal LoginService(JsonSerializer serializer, ICredentials credentials, strin
             }
 
             _credentials = credentials;
-            _token = token;
+
+            if (string.IsNullOrEmpty(token) && !string.IsNullOrEmpty(mfaSecret))
+            {
+                var secretBytes = Base32Encoding.ToBytes(mfaSecret);
+
+                var totp = new Totp(secretBytes);
+                _token = totp.ComputeTotp();
+            }
+            else
+            {
+                _token = token;
+            }
         }
         #endregion
 
diff --git a/Contentstack.Management.Core/contentstack.management.core.csproj b/Contentstack.Management.Core/contentstack.management.core.csproj
index 1fd8f92..0f14e8c 100644
--- a/Contentstack.Management.Core/contentstack.management.core.csproj
+++ b/Contentstack.Management.Core/contentstack.management.core.csproj
@@ -11,7 +11,6 @@
     <PackageLicenseFile>LICENSE.txt</PackageLicenseFile>
     <PackageProjectUrl>https://github.com/contentstack/contentstack-management-dotnet</PackageProjectUrl>
     <PackageReadmeFile>README.md</PackageReadmeFile>
-    <PackageReleaseNotes>ContentType query issue resolved</PackageReleaseNotes>
     <PackageTags>Contentstack management API </PackageTags>
     <PackageVersion>$(Version)</PackageVersion>
     <ReleaseVersion>$(Version)</ReleaseVersion>
@@ -63,6 +62,7 @@
     <Folder Include="Runtime\Pipeline\RertyHandler\" />
   </ItemGroup>
   <ItemGroup>
+    <PackageReference Include="Otp.NET" Version="1.4.0" />
     <PackageReference Include="System.Net.Http" Version="4.3.4" />
     <PackageReference Include="Microsoft.Extensions.Options" Version="9.0.2" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
diff --git a/Directory.Build.props b/Directory.Build.props
index 216b2fd..2627f35 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -1,5 +1,5 @@
 <Project>
   <PropertyGroup>
-    <Version>0.3.2</Version>
+    <Version>0.4.0</Version>
   </PropertyGroup>
 </Project>