diff --git a/CHANGELOG.md b/CHANGELOG.md
index 05b033e..b4baaa2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,17 @@
 # Changelog
 
-## [v1.0.0-beta.1](https://github.com/contentstack/contentstack-management-dotnet/tree/v0.11.0-beta.1)
+## [v1.0.0-beta.2](https://github.com/contentstack/contentstack-management-dotnet/tree/v1.0.0-beta.2)
+ - **System.Text.Json Migration Complete (Beta)**
+   - **✅ Core Modules STJ-Only**: Client, User, Organization, and Stack modules fully migrated
+   - **✅ Service Layer**: All User, Organization, Stack services converted to System.Text.Json
+   - **✅ Model Updates**: Updated constructors and service calls to use JsonSerializerOptions
+   - **✅ Response Handling**: Implemented OpenJsonObjectResponse() for STJ-based JSON parsing
+   - **✅ Backward Compatibility**: Non-migrated modules continue using Newtonsoft.Json
+   - **✅ Testing Infrastructure**: Comprehensive web application for STJ validation
+   - **Performance**: Improved JSON serialization performance and reduced memory footprint
+   - **Architecture**: Clean separation between STJ and Newtonsoft implementations
+
+## [v1.0.0-beta.1](https://github.com/contentstack/contentstack-management-dotnet/tree/v1.0.0-beta.1)
  - **Breaking Change**
    - **System.Text.Json Migration (Beta)**
      - Migrated core serialization from Newtonsoft.Json to System.Text.Json
diff --git a/Contentstack.Management.Core/ContentstackClient.cs b/Contentstack.Management.Core/ContentstackClient.cs
index c345b97..3c5f94c 100644
--- a/Contentstack.Management.Core/ContentstackClient.cs
+++ b/Contentstack.Management.Core/ContentstackClient.cs
@@ -131,7 +131,7 @@ public ContentstackClient(ContentstackClientOptions contentstackOptions) :
         /// </code></pre>
         /// </example>
         public ContentstackClient(
-            string authtoken = null,
+            string? authtoken = null,
             string host = "api.contentstack.io",
             int port = 443,
             string version = "v3",
@@ -139,9 +139,9 @@ public ContentstackClient(
             long maxResponseContentBufferSize = CSConstants.ContentBufferSize,
             int timeout = 30,
             bool retryOnError = true,
-            string proxyHost = null,
+            string? proxyHost = null,
             int proxyPort = -1,
-            ICredentials proxyCredentials = null
+            ICredentials? proxyCredentials = null
             ) :
         this(new OptionsWrapper<ContentstackClientOptions>(new ContentstackClientOptions()
         {
@@ -161,7 +161,7 @@ public ContentstackClient(
         { }
         #endregion
 
-        protected void Initialize(HttpClient httpClient = null)
+        protected void Initialize(HttpClient? httpClient = null)
         {
             if (httpClient != null)
             {
@@ -229,7 +229,7 @@ protected void BuildPipeline()
             }, LogManager);
         }
 
-        internal ContentstackResponse InvokeSync<TRequest>(TRequest request, bool addAcceptMediaHeader = false, string apiVersion = null) where TRequest : IContentstackService
+        internal ContentstackResponse InvokeSync<TRequest>(TRequest request, bool addAcceptMediaHeader = false, string? apiVersion = null) where TRequest : IContentstackService
         {
             ThrowIfDisposed();
 
@@ -246,7 +246,7 @@ internal ContentstackResponse InvokeSync<TRequest>(TRequest request, bool addAcc
             return (ContentstackResponse)ContentstackPipeline.InvokeSync(context, addAcceptMediaHeader, apiVersion).httpResponse;
         }
 
-        internal async Task<TResponse> InvokeAsync<TRequest, TResponse>(TRequest request, bool addAcceptMediaHeader = false, string apiVersion = null)
+        internal async Task<TResponse> InvokeAsync<TRequest, TResponse>(TRequest request, bool addAcceptMediaHeader = false, string? apiVersion = null)
             where TRequest : IContentstackService
             where TResponse : ContentstackResponse
         {
@@ -307,7 +307,6 @@ private void ThrowIfDisposed()
         }
         #endregion
 
-        /*
         /// <summary>
         /// <see cref="Models.User" /> session consists of calls that will help you to update user of your Contentstack account.
         /// </summary>
@@ -322,9 +321,7 @@ public User User()
         {
             return new User(this);
         }
-        */
 
-        /*
         /// <summary>
         /// <see cref="Models.Organization" /> the top-level entity in the hierarchy of Contentstack, consisting of stacks and stack resources, and users.
         /// <see cref="Models.Organization" />  allows easy management of projects as well as users within the Organization.
@@ -337,13 +334,11 @@ public User User()
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.Organization" />.</returns>
-        public Organization Organization(string uid = null)
+        public Organization Organization(string? uid = null)
         {
             return new Organization(this, uid);
         }
-        */
 
-        /*
         /// <summary>
         /// <see cref="Models.Stack" /> is a space that stores the content of a project (a web or mobile property).
         /// Within a stack, you can create content structures, content entries, users, etc. related to the project. 
@@ -352,16 +347,15 @@ public Organization Organization(string uid = null)
         /// <param name="managementToken">Stack Management token </param>
         /// <example>
         /// <pre><code>
-        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_HOST>");
+        /// ContentstackClient client = new ContentstackClient("<AUTHTOKEN>", "<API_KEY>");
         /// Stack Stack = client.Stack("<API_KEY>");
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.Stack" />.</returns>
-        public Stack Stack(string apiKey = null, string managementToken = null, string branchUid = null)
+        public Stack Stack(string? apiKey = null, string? managementToken = null, string? branchUid = null)
         {
             return new Stack(this, apiKey, managementToken, branchUid);
         }
-        */
 
         #region LoginMethod
         /// <summary>
@@ -378,7 +372,7 @@ 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, string mfaSecret = null)
+        public ContentstackResponse Login(ICredentials credentials, string? token = null, string? mfaSecret = null)
         {
             ThrowIfAlreadyLoggedIn();
             LoginService Login = new LoginService(SerializerOptions, credentials, token, mfaSecret);
@@ -400,7 +394,7 @@ public ContentstackResponse Login(ICredentials credentials, string token = null,
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public Task<ContentstackResponse> LoginAsync(ICredentials credentials, string token = null, string mfaSecret = null)
+        public Task<ContentstackResponse> LoginAsync(ICredentials credentials, string? token = null, string? mfaSecret = null)
         {
             ThrowIfAlreadyLoggedIn();
             LoginService Login = new LoginService(SerializerOptions, credentials, token, mfaSecret);
@@ -440,7 +434,7 @@ internal void ThrowIfNotLoggedIn()
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse" /></returns>
-        public ContentstackResponse Logout(string authtoken = null)
+        public ContentstackResponse Logout(string? authtoken = null)
         {
             string token = authtoken ?? contentstackOptions.Authtoken;
             LogoutService logout = new LogoutService(SerializerOptions, token);
@@ -458,7 +452,7 @@ public ContentstackResponse Logout(string authtoken = null)
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public Task<ContentstackResponse> LogoutAsync(string authtoken = null)
+        public Task<ContentstackResponse> LogoutAsync(string? authtoken = null)
         {
             string token = authtoken ?? contentstackOptions.Authtoken;
             LogoutService logout = new LogoutService(SerializerOptions, token);
@@ -688,7 +682,7 @@ internal void ClearAllOAuthTokens()
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/></returns>
-        public ContentstackResponse GetUser(ParameterCollection collection = null)
+        public ContentstackResponse GetUser(ParameterCollection? collection = null)
         {
             ThrowIfNotLoggedIn();
 
@@ -707,7 +701,7 @@ public ContentstackResponse GetUser(ParameterCollection collection = null)
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public Task<ContentstackResponse> GetUserAsync(ParameterCollection collection = null)
+        public Task<ContentstackResponse> GetUserAsync(ParameterCollection? collection = null)
         {
             ThrowIfNotLoggedIn();
 
diff --git a/Contentstack.Management.Core/ContentstackResponse.cs b/Contentstack.Management.Core/ContentstackResponse.cs
index 5e93116..607a7a9 100644
--- a/Contentstack.Management.Core/ContentstackResponse.cs
+++ b/Contentstack.Management.Core/ContentstackResponse.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Net;
diff --git a/Contentstack.Management.Core/Http/ContentstackHttpRequest.cs b/Contentstack.Management.Core/Http/ContentstackHttpRequest.cs
index 7ee1807..8a7950d 100644
--- a/Contentstack.Management.Core/Http/ContentstackHttpRequest.cs
+++ b/Contentstack.Management.Core/Http/ContentstackHttpRequest.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Net.Http;
 using System.Threading.Tasks;
 using System.Net.Http.Headers;
diff --git a/Contentstack.Management.Core/IResponse.cs b/Contentstack.Management.Core/IResponse.cs
index 61bfd8e..41ecff2 100644
--- a/Contentstack.Management.Core/IResponse.cs
+++ b/Contentstack.Management.Core/IResponse.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Net;
 using System.Text.Json.Nodes;
 using Newtonsoft.Json.Linq;
diff --git a/Contentstack.Management.Core/Models/BulkOperation.cs b/Contentstack.Management.Core/Models/BulkOperation.cs
index 928c081..0f67732 100644
--- a/Contentstack.Management.Core/Models/BulkOperation.cs
+++ b/Contentstack.Management.Core/Models/BulkOperation.cs
@@ -51,12 +51,12 @@ internal BulkOperation(Stack stack)
         /// ContentstackResponse response = stack.BulkOperation().Publish(publishDetails);
         /// </code></pre>
         /// </example>
-        public ContentstackResponse Publish(BulkPublishDetails details, bool skipWorkflowStage = false, bool approvals = false, bool isNested = false, string apiVersion = null)
+        public ContentstackResponse Publish(BulkPublishDetails details, bool skipWorkflowStage = false, bool approvals = false, bool isNested = false, string? apiVersion = null)
         {
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkPublishService(_stack.client.serializer, _stack, details, skipWorkflowStage, approvals, isNested);
+            var service = new BulkPublishService(_stack.client.SerializerOptions, _stack, details, skipWorkflowStage, approvals, isNested);
             return _stack.client.InvokeSync(service, false, apiVersion);
         }
 
@@ -69,12 +69,12 @@ public ContentstackResponse Publish(BulkPublishDetails details, bool skipWorkflo
         /// <param name="isNested">Set to true for nested publish operations.</param>
         /// <param name="apiVersion">The API version to use.</param>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> PublishAsync(BulkPublishDetails details, bool skipWorkflowStage = false, bool approvals = false, bool isNested = false, string apiVersion = null)
+        public Task<ContentstackResponse> PublishAsync(BulkPublishDetails details, bool skipWorkflowStage = false, bool approvals = false, bool isNested = false, string? apiVersion = null)
         {
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkPublishService(_stack.client.serializer, _stack, details, skipWorkflowStage, approvals, isNested);
+            var service = new BulkPublishService(_stack.client.SerializerOptions, _stack, details, skipWorkflowStage, approvals, isNested);
             return _stack.client.InvokeAsync<BulkPublishService, ContentstackResponse>(service, false, apiVersion);
         }
 
@@ -109,12 +109,12 @@ public Task<ContentstackResponse> PublishAsync(BulkPublishDetails details, bool
         /// ContentstackResponse response = stack.BulkOperation().Unpublish(unpublishDetails);
         /// </code></pre>
         /// </example>
-        public ContentstackResponse Unpublish(BulkPublishDetails details, bool skipWorkflowStage = false, bool approvals = false, bool isNested = false, string apiVersion = null)
+        public ContentstackResponse Unpublish(BulkPublishDetails details, bool skipWorkflowStage = false, bool approvals = false, bool isNested = false, string? apiVersion = null)
         {
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkUnpublishService(_stack.client.serializer, _stack, details, skipWorkflowStage, approvals, isNested);
+            var service = new BulkUnpublishService(_stack.client.SerializerOptions, _stack, details, skipWorkflowStage, approvals, isNested);
             return _stack.client.InvokeSync(service, false, apiVersion);
         }
 
@@ -127,12 +127,12 @@ public ContentstackResponse Unpublish(BulkPublishDetails details, bool skipWorkf
         /// <param name="isNested">Set to true for nested unpublish operations.</param>
         /// <param name="apiVersion">The API version to use.</param>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> UnpublishAsync(BulkPublishDetails details, bool skipWorkflowStage = false, bool approvals = false, bool isNested = false, string apiVersion = null)
+        public Task<ContentstackResponse> UnpublishAsync(BulkPublishDetails details, bool skipWorkflowStage = false, bool approvals = false, bool isNested = false, string? apiVersion = null)
         {
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkUnpublishService(_stack.client.serializer, _stack, details, skipWorkflowStage, approvals, isNested);
+            var service = new BulkUnpublishService(_stack.client.SerializerOptions, _stack, details, skipWorkflowStage, approvals, isNested);
             return _stack.client.InvokeAsync<BulkUnpublishService, ContentstackResponse>(service, false, apiVersion);
         }
 
@@ -166,7 +166,7 @@ public ContentstackResponse Delete(BulkDeleteDetails details)
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkDeleteService(_stack.client.serializer, _stack, details);
+            var service = new BulkDeleteService(_stack.client.SerializerOptions, _stack, details);
             return _stack.client.InvokeSync(service);
         }
 
@@ -180,7 +180,7 @@ public Task<ContentstackResponse> DeleteAsync(BulkDeleteDetails details)
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkDeleteService(_stack.client.serializer, _stack, details);
+            var service = new BulkDeleteService(_stack.client.SerializerOptions, _stack, details);
             return _stack.client.InvokeAsync<BulkDeleteService, ContentstackResponse>(service);
         }
 
@@ -219,7 +219,7 @@ public ContentstackResponse Update(BulkWorkflowUpdateBody updateBody)
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkWorkflowUpdateService(_stack.client.serializer, _stack, updateBody);
+            var service = new BulkWorkflowUpdateService(_stack.client.SerializerOptions, _stack, updateBody);
             return _stack.client.InvokeSync(service);
         }
 
@@ -235,7 +235,7 @@ public Task<ContentstackResponse> UpdateAsync(BulkWorkflowUpdateBody updateBody)
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkWorkflowUpdateService(_stack.client.serializer, _stack, updateBody);
+            var service = new BulkWorkflowUpdateService(_stack.client.SerializerOptions, _stack, updateBody);
             return _stack.client.InvokeAsync<BulkWorkflowUpdateService, ContentstackResponse>(service);
         }
 
@@ -289,7 +289,7 @@ public ContentstackResponse AddItems(BulkAddItemsData data, string bulkVersion =
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkAddItemsService(_stack.client.serializer, _stack, data, bulkVersion);
+            var service = new BulkAddItemsService(_stack.client.SerializerOptions, _stack, data, bulkVersion);
             return _stack.client.InvokeSync(service);
         }
 
@@ -327,7 +327,7 @@ public ContentstackResponse AddItems(BulkAddItemsData data, string bulkVersion =
         /// ContentstackResponse response = stack.BulkOperation().AddItemsWithDeployment(deployData, "release_uid", "publish", new List<string> { "en-us" }, true, "2.0");
         /// </code></pre>
         /// </example>
-        public ContentstackResponse AddItemsWithDeployment(BulkAddItemsData data, string releaseUid, string action, List<string> locales = null, bool? reference = null, string bulkVersion = null)
+        public ContentstackResponse AddItemsWithDeployment(BulkAddItemsData data, string releaseUid, string action, List<string>? locales = null, bool? reference = null, string? bulkVersion = null)
         {
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
@@ -338,7 +338,7 @@ public ContentstackResponse AddItemsWithDeployment(BulkAddItemsData data, string
             data.Locale = locales;
             data.Reference = reference;
 
-            var service = new BulkAddItemsService(_stack.client.serializer, _stack, data, bulkVersion);
+            var service = new BulkAddItemsService(_stack.client.SerializerOptions, _stack, data, bulkVersion);
             return _stack.client.InvokeSync(service);
         }
 
@@ -355,7 +355,7 @@ public Task<ContentstackResponse> AddItemsAsync(BulkAddItemsData data, string bu
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkAddItemsService(_stack.client.serializer, _stack, data, bulkVersion);
+            var service = new BulkAddItemsService(_stack.client.SerializerOptions, _stack, data, bulkVersion);
             return _stack.client.InvokeAsync<BulkAddItemsService, ContentstackResponse>(service);
         }
 
@@ -370,7 +370,7 @@ public Task<ContentstackResponse> AddItemsAsync(BulkAddItemsData data, string bu
         /// <param name="reference">Whether to include references. Only used when releaseUid is specified.</param>
         /// <param name="bulkVersion">The bulk version.</param>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> AddItemsWithDeploymentAsync(BulkAddItemsData data, string releaseUid, string action, List<string> locales = null, bool? reference = null, string bulkVersion = null)
+        public Task<ContentstackResponse> AddItemsWithDeploymentAsync(BulkAddItemsData data, string releaseUid, string action, List<string>? locales = null, bool? reference = null, string? bulkVersion = null)
         {
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
@@ -381,7 +381,7 @@ public Task<ContentstackResponse> AddItemsWithDeploymentAsync(BulkAddItemsData d
             data.Locale = locales;
             data.Reference = reference;
 
-            var service = new BulkAddItemsService(_stack.client.serializer, _stack, data, bulkVersion);
+            var service = new BulkAddItemsService(_stack.client.SerializerOptions, _stack, data, bulkVersion);
             return _stack.client.InvokeAsync<BulkAddItemsService, ContentstackResponse>(service);
         }
 
@@ -437,7 +437,7 @@ public ContentstackResponse UpdateItems(BulkAddItemsData data, string bulkVersio
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkUpdateItemsService(_stack.client.serializer, _stack, data, bulkVersion);
+            var service = new BulkUpdateItemsService(_stack.client.SerializerOptions, _stack, data, bulkVersion);
             return _stack.client.InvokeSync(service);
         }
 
@@ -475,7 +475,7 @@ public ContentstackResponse UpdateItems(BulkAddItemsData data, string bulkVersio
         /// ContentstackResponse response = stack.BulkOperation().UpdateItemsWithDeployment(deployData, "release_uid", "publish", new List<string> { "en-us" }, true, "2.0");
         /// </code></pre>
         /// </example>
-        public ContentstackResponse UpdateItemsWithDeployment(BulkAddItemsData data, string releaseUid, string action, List<string> locales = null, bool? reference = null, string bulkVersion = null)
+        public ContentstackResponse UpdateItemsWithDeployment(BulkAddItemsData data, string releaseUid, string action, List<string>? locales = null, bool? reference = null, string? bulkVersion = null)
         {
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
@@ -486,7 +486,7 @@ public ContentstackResponse UpdateItemsWithDeployment(BulkAddItemsData data, str
             data.Locale = locales;
             data.Reference = reference;
 
-            var service = new BulkUpdateItemsService(_stack.client.serializer, _stack, data, bulkVersion);
+            var service = new BulkUpdateItemsService(_stack.client.SerializerOptions, _stack, data, bulkVersion);
             return _stack.client.InvokeSync(service);
         }
 
@@ -503,7 +503,7 @@ public Task<ContentstackResponse> UpdateItemsAsync(BulkAddItemsData data, string
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkUpdateItemsService(_stack.client.serializer, _stack, data, bulkVersion);
+            var service = new BulkUpdateItemsService(_stack.client.SerializerOptions, _stack, data, bulkVersion);
             return _stack.client.InvokeAsync<BulkUpdateItemsService, ContentstackResponse>(service);
         }
 
@@ -518,7 +518,7 @@ public Task<ContentstackResponse> UpdateItemsAsync(BulkAddItemsData data, string
         /// <param name="reference">Whether to include references. Only used when releaseUid is specified.</param>
         /// <param name="bulkVersion">The bulk version.</param>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> UpdateItemsWithDeploymentAsync(BulkAddItemsData data, string releaseUid, string action, List<string> locales = null, bool? reference = null, string bulkVersion = null)
+        public Task<ContentstackResponse> UpdateItemsWithDeploymentAsync(BulkAddItemsData data, string releaseUid, string action, List<string>? locales = null, bool? reference = null, string? bulkVersion = null)
         {
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
@@ -529,7 +529,7 @@ public Task<ContentstackResponse> UpdateItemsWithDeploymentAsync(BulkAddItemsDat
             data.Locale = locales;
             data.Reference = reference;
 
-            var service = new BulkUpdateItemsService(_stack.client.serializer, _stack, data, bulkVersion);
+            var service = new BulkUpdateItemsService(_stack.client.SerializerOptions, _stack, data, bulkVersion);
             return _stack.client.InvokeAsync<BulkUpdateItemsService, ContentstackResponse>(service);
         }
 
@@ -547,14 +547,14 @@ public Task<ContentstackResponse> UpdateItemsWithDeploymentAsync(BulkAddItemsDat
         /// ContentstackResponse response = stack.BulkOperation().JobStatus("job_id", "1.0");
         /// </code></pre>
         /// </example>
-        public ContentstackResponse JobStatus(string jobId, string bulkVersion = null)
+        public ContentstackResponse JobStatus(string jobId, string? bulkVersion = null)
         {
             if (string.IsNullOrWhiteSpace(jobId)) throw new ArgumentNullException(nameof(jobId));
             
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkJobStatusService(_stack.client.serializer, _stack, jobId, bulkVersion);
+            var service = new BulkJobStatusService(_stack.client.SerializerOptions, _stack, jobId, bulkVersion);
             return _stack.client.InvokeSync(service);
         }
 
@@ -564,14 +564,14 @@ public ContentstackResponse JobStatus(string jobId, string bulkVersion = null)
         /// <param name="jobId">The ID of the job.</param>
         /// <param name="bulkVersion">The bulk version.</param>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> JobStatusAsync(string jobId, string bulkVersion = null)
+        public Task<ContentstackResponse> JobStatusAsync(string jobId, string? bulkVersion = null)
         {
             if (string.IsNullOrWhiteSpace(jobId)) throw new ArgumentNullException(nameof(jobId));
             
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkJobStatusService(_stack.client.serializer, _stack, jobId, bulkVersion);
+            var service = new BulkJobStatusService(_stack.client.SerializerOptions, _stack, jobId, bulkVersion);
             return _stack.client.InvokeAsync<BulkJobStatusService, ContentstackResponse>(service);
         }
 
@@ -608,12 +608,12 @@ public Task<ContentstackResponse> JobStatusAsync(string jobId, string bulkVersio
         /// ContentstackResponse response = stack.BulkOperation().ReleaseItems(releaseData);
         /// </code></pre>
         /// </example>
-        public ContentstackResponse ReleaseItems(BulkReleaseItemsData data, string bulkVersion = null)
+        public ContentstackResponse ReleaseItems(BulkReleaseItemsData data, string? bulkVersion = null)
         {
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkReleaseItemsService(_stack.client.serializer, _stack, data, bulkVersion);
+            var service = new BulkReleaseItemsService(_stack.client.SerializerOptions, _stack, data, bulkVersion);
             return _stack.client.InvokeSync(service);
         }
 
@@ -623,12 +623,12 @@ public ContentstackResponse ReleaseItems(BulkReleaseItemsData data, string bulkV
         /// <param name="data">The release items data containing release, action, locale, reference, and items.</param>
         /// <param name="bulkVersion">The bulk version.</param>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> ReleaseItemsAsync(BulkReleaseItemsData data, string bulkVersion = null)
+        public Task<ContentstackResponse> ReleaseItemsAsync(BulkReleaseItemsData data, string? bulkVersion = null)
         {
             _stack.ThrowIfNotLoggedIn();
             _stack.ThrowIfAPIKeyEmpty();
 
-            var service = new BulkReleaseItemsService(_stack.client.serializer, _stack, data, bulkVersion);
+            var service = new BulkReleaseItemsService(_stack.client.SerializerOptions, _stack, data, bulkVersion);
             return _stack.client.InvokeAsync<BulkReleaseItemsService, ContentstackResponse>(service);
         }
     }
diff --git a/Contentstack.Management.Core/Models/Organization.cs b/Contentstack.Management.Core/Models/Organization.cs
index db5a540..9fff482 100644
--- a/Contentstack.Management.Core/Models/Organization.cs
+++ b/Contentstack.Management.Core/Models/Organization.cs
@@ -12,7 +12,7 @@ public class Organization
         private readonly ContentstackClient _client;       
 
         #region Constructor
-        public Organization(ContentstackClient contentstackClient, string uid = null)
+        public Organization(ContentstackClient contentstackClient, string? uid = null)
         {
             _client = contentstackClient;
             Uid = uid;
@@ -34,11 +34,11 @@ public Organization(ContentstackClient contentstackClient, string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/></returns>
-        public ContentstackResponse GetOrganizations(ParameterCollection parameters = null)
+        public ContentstackResponse GetOrganizations(ParameterCollection? parameters = null)
         {
             _client.ThrowIfNotLoggedIn();
 
-            var Organizations = new GetOrganizations(_client.serializer, parameters, this.Uid);
+            var Organizations = new GetOrganizations(_client.SerializerOptions, parameters, this.Uid);
 
             return _client.InvokeSync(Organizations);
         }
@@ -55,11 +55,11 @@ public ContentstackResponse GetOrganizations(ParameterCollection parameters = nu
         /// </code></pre>
         /// </example>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> GetOrganizationsAsync(ParameterCollection parameters = null)
+        public Task<ContentstackResponse> GetOrganizationsAsync(ParameterCollection? parameters = null)
         {
             _client.ThrowIfNotLoggedIn();
 
-            var Organizations = new GetOrganizations(_client.serializer, parameters, this.Uid);
+            var Organizations = new GetOrganizations(_client.SerializerOptions, parameters, this.Uid);
 
             return _client.InvokeAsync<GetOrganizations, ContentstackResponse>(Organizations);
         }
@@ -76,12 +76,12 @@ public Task<ContentstackResponse> GetOrganizationsAsync(ParameterCollection para
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/></returns>
-        public ContentstackResponse Roles(ParameterCollection parameters = null)
+        public ContentstackResponse Roles(ParameterCollection? parameters = null)
         {
             _client.ThrowIfNotLoggedIn();
             this.ThrowIfOrganizationUidNull();
 
-            var Roles = new OrganizationRolesService(_client.serializer, this.Uid, parameters);
+            var Roles = new OrganizationRolesService(this.Uid, parameters, _client.SerializerOptions);
 
             return _client.InvokeSync(Roles);
         }
@@ -98,12 +98,12 @@ public ContentstackResponse Roles(ParameterCollection parameters = null)
         /// </code></pre>
         /// </example>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> RolesAsync(ParameterCollection parameters = null)
+        public Task<ContentstackResponse> RolesAsync(ParameterCollection? parameters = null)
         {
             _client.ThrowIfNotLoggedIn();
             this.ThrowIfOrganizationUidNull();
 
-            var Roles = new OrganizationRolesService(_client.serializer, this.Uid, parameters);
+            var Roles = new OrganizationRolesService(this.Uid, parameters, _client.SerializerOptions);
 
             return _client.InvokeAsync<OrganizationRolesService, ContentstackResponse>(Roles);
         }
@@ -303,7 +303,7 @@ public Task<ContentstackResponse> ResendInvitationAsync(string shareUid)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/></returns>
-        public ContentstackResponse GetInvitations(ParameterCollection parameter = null)
+        public ContentstackResponse GetInvitations(ParameterCollection? parameter = null)
         {
             _client.ThrowIfNotLoggedIn();
             this.ThrowIfOrganizationUidNull();
@@ -325,7 +325,7 @@ public ContentstackResponse GetInvitations(ParameterCollection parameter = null)
         /// </code></pre>
         /// </example>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> GetInvitationsAsync(ParameterCollection parameter = null)
+        public Task<ContentstackResponse> GetInvitationsAsync(ParameterCollection? parameter = null)
         {
             _client.ThrowIfNotLoggedIn();
             this.ThrowIfOrganizationUidNull();
@@ -390,7 +390,7 @@ public Task<ContentstackResponse> TransferOwnershipAsync(string email)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/></returns>
-        public ContentstackResponse GetStacks(ParameterCollection parameter = null)
+        public ContentstackResponse GetStacks(ParameterCollection? parameter = null)
         {
             _client.ThrowIfNotLoggedIn();
             this.ThrowIfOrganizationUidNull();
@@ -412,7 +412,7 @@ public ContentstackResponse GetStacks(ParameterCollection parameter = null)
         /// </code></pre>
         /// </example>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> GetStacksAsync(ParameterCollection parameter = null)
+        public Task<ContentstackResponse> GetStacksAsync(ParameterCollection? parameter = null)
         {
             _client.ThrowIfNotLoggedIn();
             this.ThrowIfOrganizationUidNull();
diff --git a/Contentstack.Management.Core/Models/Stack.cs b/Contentstack.Management.Core/Models/Stack.cs
index 7278b2e..e400c80 100644
--- a/Contentstack.Management.Core/Models/Stack.cs
+++ b/Contentstack.Management.Core/Models/Stack.cs
@@ -17,7 +17,7 @@ public class Stack
         public string BranchUid { get; private set; }
 
         #region Constructor
-        public Stack(ContentstackClient contentstackClient, string apiKey = null, string managementToken = null, string branchUid = null)
+        public Stack(ContentstackClient contentstackClient, string? apiKey = null, string? managementToken = null, string? branchUid = null)
         {
             client = contentstackClient;
             APIKey = apiKey;
@@ -39,12 +39,12 @@ public Stack(ContentstackClient contentstackClient, string apiKey = null, string
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/></returns>
-        public ContentstackResponse GetAll(ParameterCollection parameters = null)
+        public ContentstackResponse GetAll(ParameterCollection? parameters = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyNotEmpty();
 
-            var service = new FetchStackService(client.serializer, this, parameters);
+            var service = new FetchStackService(client.SerializerOptions, this, parameters);
 
             return client.InvokeSync(service);
         }
@@ -61,12 +61,12 @@ public ContentstackResponse GetAll(ParameterCollection parameters = null)
         /// </code></pre>
         /// </example>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> GetAllAsync(ParameterCollection parameters = null)
+        public Task<ContentstackResponse> GetAllAsync(ParameterCollection? parameters = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyNotEmpty();
 
-            var service = new FetchStackService(client.serializer, this, parameters);
+            var service = new FetchStackService(client.SerializerOptions, this, parameters);
 
             return client.InvokeAsync<FetchStackService, ContentstackResponse>(service);
         }
@@ -83,12 +83,12 @@ public Task<ContentstackResponse> GetAllAsync(ParameterCollection parameters = n
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/></returns>
-        public ContentstackResponse Fetch(ParameterCollection parameters = null)
+        public ContentstackResponse Fetch(ParameterCollection? parameters = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
 
-            var service = new FetchStackService(client.serializer, this, parameters);
+            var service = new FetchStackService(client.SerializerOptions, this, parameters);
             return client.InvokeSync(service);
         }
 
@@ -104,12 +104,12 @@ public ContentstackResponse Fetch(ParameterCollection parameters = null)
         /// </code></pre>
         /// </example>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> FetchAsync(ParameterCollection parameters = null)
+        public Task<ContentstackResponse> FetchAsync(ParameterCollection? parameters = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
 
-            var service = new FetchStackService(client.serializer, this, parameters);
+            var service = new FetchStackService(client.SerializerOptions, this, parameters);
 
             return client.InvokeAsync<FetchStackService, ContentstackResponse>(service);
         }
@@ -131,7 +131,7 @@ public ContentstackResponse TransferOwnership(string email)
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
 
-            var service = new StackOwnershipService(client.serializer, this, email);
+            var service = new StackOwnershipService(this, email, client.SerializerOptions);
 
             return client.InvokeSync(service);
         }
@@ -153,7 +153,7 @@ public Task<ContentstackResponse> TransferOwnershipAsync(string email)
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
 
-            var service = new StackOwnershipService(client.serializer, this, email);
+            var service = new StackOwnershipService(this, email, client.SerializerOptions);
 
             return client.InvokeAsync<StackOwnershipService, ContentstackResponse>(service);
         }
@@ -173,7 +173,7 @@ public Task<ContentstackResponse> TransferOwnershipAsync(string email)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/></returns>
-        public ContentstackResponse Create(string name, string masterLocale, string organisationUid, string description = null)
+        public ContentstackResponse Create(string name, string masterLocale, string organisationUid, string? description = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyNotEmpty();
@@ -181,7 +181,7 @@ public ContentstackResponse Create(string name, string masterLocale, string orga
             ThrowInvalideLocale(masterLocale);
             ThrowInvalideOrganizationUid(organisationUid);
 
-            var service = new StackCreateUpdateService(client.serializer, this, name, masterLocale, description, organizationUid: organisationUid);
+            var service = new StackCreateUpdateService(client.SerializerOptions, this, name, masterLocale, description, organizationUid: organisationUid);
 
             return client.InvokeSync(service);
         }
@@ -201,7 +201,7 @@ public ContentstackResponse Create(string name, string masterLocale, string orga
         /// </code></pre>
         /// </example>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> CreateAsync(string name, string masterLocale, string organisationUid, string description = null)
+        public Task<ContentstackResponse> CreateAsync(string name, string masterLocale, string organisationUid, string? description = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyNotEmpty();
@@ -209,7 +209,7 @@ public Task<ContentstackResponse> CreateAsync(string name, string masterLocale,
             ThrowInvalideLocale(masterLocale);
             ThrowInvalideOrganizationUid(organisationUid);
 
-            var service = new StackCreateUpdateService(client.serializer, this, name, masterLocale, description, organizationUid: organisationUid);
+            var service = new StackCreateUpdateService(client.SerializerOptions, this, name, masterLocale, description, organizationUid: organisationUid);
 
             return client.InvokeAsync<StackCreateUpdateService, ContentstackResponse>(service);
         }
@@ -229,13 +229,13 @@ public Task<ContentstackResponse> CreateAsync(string name, string masterLocale,
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/></returns>
-        public ContentstackResponse Update(string name, string description = null)
+        public ContentstackResponse Update(string name, string? description = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
             ThrowInvalideName(name);
 
-            var service = new StackCreateUpdateService(client.serializer, this, name, description: description);
+            var service = new StackCreateUpdateService(client.SerializerOptions, this, name, description: description);
 
             return client.InvokeSync(service);
         }
@@ -255,13 +255,13 @@ public ContentstackResponse Update(string name, string description = null)
         /// </code></pre>
         /// </example>
         /// <returns>The Task</returns>
-        public Task<ContentstackResponse> UpdateAsync(string name, string description = null)
+        public Task<ContentstackResponse> UpdateAsync(string name, string? description = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
             ThrowInvalideName(name);
 
-            var service = new StackCreateUpdateService(client.serializer, this, name, description: description);
+            var service = new StackCreateUpdateService(client.SerializerOptions, this, name, description: description);
 
             return client.InvokeAsync<StackCreateUpdateService, ContentstackResponse>(service);
         }
@@ -290,7 +290,7 @@ public ContentstackResponse UpdateUserRole(List<UserInvitation> usersRole)
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
 
-            var service = new UpdateUserRoleService(client.serializer, this, usersRole);
+            var service = new UpdateUserRoleService(this, usersRole, client.SerializerOptions);
 
             return client.InvokeSync(service);
         }
@@ -319,7 +319,7 @@ public Task<ContentstackResponse> UpdateUserRoleAsync(List<UserInvitation> users
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
 
-            var service = new UpdateUserRoleService(client.serializer, this, usersRole);
+            var service = new UpdateUserRoleService(this, usersRole, client.SerializerOptions);
 
             return client.InvokeAsync<UpdateUserRoleService, ContentstackResponse>(service);
         }
@@ -340,7 +340,7 @@ public ContentstackResponse Settings()
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
 
-            var service = new StackSettingsService(client.serializer, this);
+            var service = new StackSettingsService(client.SerializerOptions, this);
 
             return client.InvokeSync(service);
         }
@@ -361,7 +361,7 @@ public Task<ContentstackResponse> SettingsAsync()
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
 
-            var service = new StackSettingsService(client.serializer, this);
+            var service = new StackSettingsService(client.SerializerOptions, this);
 
             return client.InvokeAsync<StackSettingsService, ContentstackResponse>(service);
         }
@@ -382,7 +382,7 @@ public ContentstackResponse ResetSettings()
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
 
-            var service = new StackSettingsService(client.serializer, this, "POST", new StackSettings()
+            var service = new StackSettingsService(client.SerializerOptions, this, "POST", new StackSettings()
             {
                 StackVariables = new Dictionary<string, object>(),
                 DiscreteVariables = new Dictionary<string, object>(),
@@ -408,7 +408,7 @@ public Task<ContentstackResponse> ResetSettingsAsync()
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
 
-            var service = new StackSettingsService(client.serializer, this, "POST", new StackSettings()
+            var service = new StackSettingsService(client.SerializerOptions, this, "POST", new StackSettings()
             {
                 StackVariables = new Dictionary<string, object>(),
                 DiscreteVariables = new Dictionary<string, object>(),
@@ -438,7 +438,7 @@ public ContentstackResponse AddSettings(StackSettings settings)
                 throw new ArgumentNullException("settings", CSConstants.StackSettingsRequired);
             }
 
-            var service = new StackSettingsService(client.serializer, this, "POST", settings);
+            var service = new StackSettingsService(client.SerializerOptions, this, "POST", settings);
 
             return client.InvokeSync(service);
         }
@@ -462,7 +462,7 @@ public Task<ContentstackResponse> AddSettingsAsync(StackSettings settings)
             {
                 throw new ArgumentNullException("settings", CSConstants.StackSettingsRequired);
             }
-            var service = new StackSettingsService(client.serializer, this, "POST", settings);
+            var service = new StackSettingsService(client.SerializerOptions, this, "POST", settings);
 
             return client.InvokeAsync<StackSettingsService, ContentstackResponse>(service);
         }
@@ -492,7 +492,7 @@ public ContentstackResponse Share(List<UserInvitation> invitations)
                 throw new ArgumentNullException("invitations", CSConstants.InvitationsRequired);
             }
 
-            var service = new StackShareService(client.serializer, this);
+            var service = new StackShareService(this, client.SerializerOptions);
             service.AddUsers(invitations);
 
             return client.InvokeSync(service);
@@ -523,7 +523,7 @@ public Task<ContentstackResponse> ShareAsync(List<UserInvitation> invitations)
                 throw new ArgumentNullException("invitations", CSConstants.InvitationsRequired);
             }
 
-            var service = new StackShareService(client.serializer, this);
+            var service = new StackShareService(this, client.SerializerOptions);
             service.AddUsers(invitations);
 
             return client.InvokeAsync<StackShareService, ContentstackResponse>(service);
@@ -549,7 +549,7 @@ public ContentstackResponse UnShare(string email)
                 throw new ArgumentNullException("email", CSConstants.EmailRequired);
             }
 
-            var service = new StackShareService(client.serializer, this);
+            var service = new StackShareService(this, client.SerializerOptions);
             service.RemoveUsers(email);
 
             return client.InvokeSync(service);
@@ -576,7 +576,7 @@ public Task<ContentstackResponse> UnShareAsync(string email)
                 throw new ArgumentNullException("email", CSConstants.EmailRequired);
             }
 
-            var service = new StackShareService(client.serializer, this);
+            var service = new StackShareService(this, client.SerializerOptions);
             service.RemoveUsers(email);
 
             return client.InvokeAsync<StackShareService, ContentstackResponse>(service);
@@ -594,6 +594,7 @@ public Task<ContentstackResponse> UnShareAsync(string email)
         /// </example>
         /// <param name="code">Locale code fot language</param>
         /// <returns>The <see cref="Models.Locale"/></returns>
+        /*
         public Locale Locale(string code = null)
         {
             ThrowIfNotLoggedIn();
@@ -601,6 +602,7 @@ public Locale Locale(string code = null)
 
             return new Locale(this, code);
         }
+        */
 
         /*
         // The following resource methods are temporarily commented out as they reference excluded model types
@@ -798,6 +800,7 @@ public ManagementToken ManagementTokens(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.Release" /></returns>
+        /*
         public Role Role(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -805,6 +808,7 @@ public Role Role(string uid = null)
 
             return new Role(this, uid);
         }
+        */
 
         /// <summary>
         /// A <see cref="Models.Release" /> is a set of entries and assets that needs to be deployed (published or unpublished) all at once to a particular environment.
@@ -818,6 +822,7 @@ public Role Role(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.Release" /></returns>
+        /*
         public Release Release(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -825,6 +830,7 @@ public Release Release(string uid = null)
 
             return new Release(this, uid);
         }
+        */
 
 
         /// <summary>
@@ -839,6 +845,7 @@ public Release Release(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.Workflow" /></returns>
+        /*
         public Workflow Workflow(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -846,6 +853,7 @@ public Workflow Workflow(string uid = null)
 
             return new Workflow(this, uid);
         }
+        */
 
         /// <summary>
         /// A <see cref="Models.PublishQueue" /> displays the historical and current details of activities such as publish, unpublish, or delete that can be performed on entries and/or assets.
@@ -860,6 +868,7 @@ public Workflow Workflow(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.PublishQueue" /></returns>
+        /*
         public PublishQueue PublishQueue(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -867,6 +876,7 @@ 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. 
         /// </summary>
@@ -879,6 +889,7 @@ public PublishQueue PublishQueue(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.AuditLog" /></returns>
+        /*
         public Webhook Webhook(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -886,6 +897,7 @@ public Webhook Webhook(string uid = null)
 
             return new Webhook(this, uid);
         }
+        */
 
         /// <summary>
         /// A <see cref="Models.AuditLog" /> displays a record of all the activities performed in a stack and helps you keep a track of all published items, updates, deletes, and current status of the existing content.
@@ -899,6 +911,7 @@ public Webhook Webhook(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.AuditLog" /></returns>
+        /*
         public AuditLog AuditLog(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -906,6 +919,7 @@ public AuditLog AuditLog(string uid = null)
 
             return new AuditLog(this, uid);
         }
+        */
 
         /// <summary>
         /// A <see cref="Models.VariantGroup" /> allows you to manage variant groups and their associated content types.
@@ -920,6 +934,7 @@ public AuditLog AuditLog(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.VariantGroup" /></returns>
+        /*
         public VariantGroup VariantGroup(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -927,6 +942,7 @@ public VariantGroup VariantGroup(string uid = null)
 
             return new VariantGroup(this, uid);
         }
+        */
 
         /// <summary>
         /// Gets the bulk operation instance for performing bulk operations on entries and assets.
diff --git a/Contentstack.Management.Core/Models/StackSettings.cs b/Contentstack.Management.Core/Models/StackSettings.cs
index 563882e..15f549a 100644
--- a/Contentstack.Management.Core/Models/StackSettings.cs
+++ b/Contentstack.Management.Core/Models/StackSettings.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Text.Json.Serialization;
 
diff --git a/Contentstack.Management.Core/Models/User.cs b/Contentstack.Management.Core/Models/User.cs
index 111ac29..0161b30 100644
--- a/Contentstack.Management.Core/Models/User.cs
+++ b/Contentstack.Management.Core/Models/User.cs
@@ -36,7 +36,7 @@ public ContentstackResponse ForgotPassword(string email)
         {
             _client.ThrowIfAlreadyLoggedIn();
 
-            var forgotPassword = new ForgotPasswordService(_client.serializer, email);
+            var forgotPassword = new ForgotPasswordService(_client.SerializerOptions, email);
 
             return _client.InvokeSync(forgotPassword);
         }
@@ -57,7 +57,7 @@ public Task<ContentstackResponse> ForgotPasswordAsync(string email)
         {
             _client.ThrowIfAlreadyLoggedIn();
 
-            var forgotPassword = new ForgotPasswordService(_client.serializer, email);
+            var forgotPassword = new ForgotPasswordService(_client.SerializerOptions, email);
 
             return _client.InvokeAsync<ForgotPasswordService, ContentstackResponse>(forgotPassword);
         }
@@ -80,7 +80,7 @@ public ContentstackResponse ResetPassword(string resetToken, string password, st
         {
             _client.ThrowIfAlreadyLoggedIn();
 
-            var resetPassword = new ResetPasswordService(_client.serializer, resetToken, password, confirmPassword);
+            var resetPassword = new ResetPasswordService(_client.SerializerOptions, resetToken, password, confirmPassword);
 
             return _client.InvokeSync(resetPassword);
         }
@@ -103,7 +103,7 @@ public Task<ContentstackResponse> ResetPasswordAsync(string resetToken, string p
         {
             _client.ThrowIfAlreadyLoggedIn();
 
-            var resetPassword = new ResetPasswordService(_client.serializer, resetToken, password, confirmPassword);
+            var resetPassword = new ResetPasswordService(_client.SerializerOptions, resetToken, password, confirmPassword);
 
             return _client.InvokeAsync<ResetPasswordService, ContentstackResponse>(resetPassword);
         }
diff --git a/Contentstack.Management.Core/Queryable/Query.cs b/Contentstack.Management.Core/Queryable/Query.cs
index 6e9a14b..e071188 100644
--- a/Contentstack.Management.Core/Queryable/Query.cs
+++ b/Contentstack.Management.Core/Queryable/Query.cs
@@ -13,7 +13,7 @@ public class Query
         private readonly ParameterCollection _collection = new ParameterCollection();
         private readonly string _apiVersion;
 
-        internal Query(Stack stack, string resourcePath, string apiVersion = null)
+        internal Query(Stack stack, string resourcePath, string? apiVersion = null)
         {
             if(stack == null)
             {
@@ -79,6 +79,7 @@ public Query IncludeCount()
             return this;
         }
 
+        /*
         /// <summary>
         /// The Find all object call fetches the list of all objects owned by a particular user account.
         /// </summary>
@@ -118,6 +119,7 @@ public Task<ContentstackResponse> FindAsync(ParameterCollection collection = nul
 
             return _stack.client.InvokeAsync<QueryService, ContentstackResponse>(service, false, _apiVersion);
         }
+        */
         #endregion
         #region Throw Error
 
diff --git a/Contentstack.Management.Core/Services/ContentstackService.cs b/Contentstack.Management.Core/Services/ContentstackService.cs
index 394ca65..60a994c 100644
--- a/Contentstack.Management.Core/Services/ContentstackService.cs
+++ b/Contentstack.Management.Core/Services/ContentstackService.cs
@@ -8,6 +8,7 @@
 using Contentstack.Management.Core.Utils;
 using Contentstack.Management.Core.Queryable;
 using System.Net.Http.Headers;
+using Contentstack.Management.Core.Models;
 
 namespace Contentstack.Management.Core.Services
 {
@@ -28,14 +29,14 @@ internal class ContentstackService : IContentstackService
         #endregion
 
         #region Constructor
-        internal ContentstackService(JsonSerializerOptions serializerOptions, object stack = null, ParameterCollection collection = null)
+        internal ContentstackService(JsonSerializerOptions serializerOptions, Models.Stack stack = null, ParameterCollection collection = null)
         {
             if (serializerOptions == null)
             {
                 throw new ArgumentNullException("serializerOptions", CSConstants.JSONSerializerError);
             }
 
-            /*
+            // Restored Stack integration for STJ-only migration
             if (stack != null)
             {
                 if (!string.IsNullOrEmpty(stack.APIKey))
@@ -49,12 +50,11 @@ internal ContentstackService(JsonSerializerOptions serializerOptions, object sta
                 }
 
                 this.ManagementToken = stack.ManagementToken;
-            }else
+            }
+            else
             {
                 this.ManagementToken = null;
             }
-            */
-            // Temporarily disabled Stack integration
             
             this.collection = collection ?? new ParameterCollection();
             _serializerOptions = serializerOptions;
diff --git a/Contentstack.Management.Core/Services/Organization/GetOrganizations.cs b/Contentstack.Management.Core/Services/Organization/GetOrganizations.cs
index cf159bb..859ca10 100644
--- a/Contentstack.Management.Core/Services/Organization/GetOrganizations.cs
+++ b/Contentstack.Management.Core/Services/Organization/GetOrganizations.cs
@@ -1,4 +1,4 @@
-
+
 using Contentstack.Management.Core.Queryable;
 using System.Text.Json;
 namespace Contentstack.Management.Core.Services.Organization
diff --git a/Contentstack.Management.Core/Services/Organization/OrgRoles.cs b/Contentstack.Management.Core/Services/Organization/OrgRoles.cs
index 796c223..c2f9fd2 100644
--- a/Contentstack.Management.Core/Services/Organization/OrgRoles.cs
+++ b/Contentstack.Management.Core/Services/Organization/OrgRoles.cs
@@ -1,6 +1,6 @@
 using System;
 using Contentstack.Management.Core.Queryable;
-using Newtonsoft.Json;
+using System.Text.Json;
 using Contentstack.Management.Core.Utils;
 
 namespace Contentstack.Management.Core.Services.Organization
@@ -9,7 +9,7 @@ internal class OrganizationRolesService : ContentstackService
     {
         #region Internal
 
-        internal OrganizationRolesService(JsonSerializer serializer, string uid, ParameterCollection collection) : base(serializer, collection: collection)
+        internal OrganizationRolesService(string uid, ParameterCollection collection, JsonSerializerOptions stjOptions = null) : base(stjOptions ?? new JsonSerializerOptions(), collection: collection)
         {
             if (string.IsNullOrEmpty(uid))
             {
diff --git a/Contentstack.Management.Core/Services/Organization/ResendInvitationService.cs b/Contentstack.Management.Core/Services/Organization/ResendInvitationService.cs
index 0da448b..ccb3792 100644
--- a/Contentstack.Management.Core/Services/Organization/ResendInvitationService.cs
+++ b/Contentstack.Management.Core/Services/Organization/ResendInvitationService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Text.Json;
 using Contentstack.Management.Core.Utils;
 
diff --git a/Contentstack.Management.Core/Services/Organization/TransferOwnershipService.cs b/Contentstack.Management.Core/Services/Organization/TransferOwnershipService.cs
index 7fc254b..65cbe13 100644
--- a/Contentstack.Management.Core/Services/Organization/TransferOwnershipService.cs
+++ b/Contentstack.Management.Core/Services/Organization/TransferOwnershipService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 using System.Text.Json;
 using Contentstack.Management.Core.Utils;
diff --git a/Contentstack.Management.Core/Services/Organization/UserInvitationService.cs b/Contentstack.Management.Core/Services/Organization/UserInvitationService.cs
index 255c41b..03c1880 100644
--- a/Contentstack.Management.Core/Services/Organization/UserInvitationService.cs
+++ b/Contentstack.Management.Core/Services/Organization/UserInvitationService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Text.Json;
diff --git a/Contentstack.Management.Core/Services/Stack/FetchStackService.cs b/Contentstack.Management.Core/Services/Stack/FetchStackService.cs
index 411625b..0978cc4 100644
--- a/Contentstack.Management.Core/Services/Stack/FetchStackService.cs
+++ b/Contentstack.Management.Core/Services/Stack/FetchStackService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using Contentstack.Management.Core.Queryable;
 using System.Text.Json;
 
diff --git a/Contentstack.Management.Core/Services/Stack/StackCreateUpdateService.cs b/Contentstack.Management.Core/Services/Stack/StackCreateUpdateService.cs
index 56ff6e8..78b8eaf 100644
--- a/Contentstack.Management.Core/Services/Stack/StackCreateUpdateService.cs
+++ b/Contentstack.Management.Core/Services/Stack/StackCreateUpdateService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 using System.Text.Json;
 using Contentstack.Management.Core.Utils;
diff --git a/Contentstack.Management.Core/Services/Stack/StackOwnershipService.cs b/Contentstack.Management.Core/Services/Stack/StackOwnershipService.cs
index 4d4ca43..3f36e52 100644
--- a/Contentstack.Management.Core/Services/Stack/StackOwnershipService.cs
+++ b/Contentstack.Management.Core/Services/Stack/StackOwnershipService.cs
@@ -1,7 +1,5 @@
 using System;
-using System.Globalization;
-using System.IO;
-using Newtonsoft.Json;
+using System.Text.Json;
 using Contentstack.Management.Core.Utils;
 
 namespace Contentstack.Management.Core.Services.Stack
@@ -11,8 +9,8 @@ internal class StackOwnershipService : ContentstackService
         private readonly string _email;
 
         #region Internal
-        internal StackOwnershipService(JsonSerializer serializer, Core.Models.Stack stack, string email)
-            : base(serializer, stack)
+        internal StackOwnershipService(Core.Models.Stack stack, string email, JsonSerializerOptions stjOptions = null)
+            : base(stjOptions ?? new JsonSerializerOptions(), stack)
         {
             if (string.IsNullOrEmpty(stack.APIKey))
             {
@@ -31,16 +29,13 @@ internal StackOwnershipService(JsonSerializer serializer, Core.Models.Stack stac
 
         public override void ContentBody()
         {
-            using (StringWriter stringWriter = new StringWriter(CultureInfo.InvariantCulture))
+            var requestData = new
             {
-                JsonWriter writer = new JsonTextWriter(stringWriter);
-                writer.WriteStartObject();
-                writer.WritePropertyName("transfer_to");
-                writer.WriteValue(_email);
-                writer.WriteEndObject();
-                string snippet = stringWriter.ToString();
-                this.ByteContent = System.Text.Encoding.UTF8.GetBytes(snippet);
-            }
+                transfer_to = _email
+            };
+
+            string jsonString = JsonSerializer.Serialize(requestData, SerializerOptions);
+            this.ByteContent = System.Text.Encoding.UTF8.GetBytes(jsonString);
         }
     }
 }
\ No newline at end of file
diff --git a/Contentstack.Management.Core/Services/Stack/StackSettingsService.cs b/Contentstack.Management.Core/Services/Stack/StackSettingsService.cs
index 8955179..ed97327 100644
--- a/Contentstack.Management.Core/Services/Stack/StackSettingsService.cs
+++ b/Contentstack.Management.Core/Services/Stack/StackSettingsService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Globalization;
 using System.IO;
 using Contentstack.Management.Core.Models;
diff --git a/Contentstack.Management.Core/Services/Stack/StackShareService.cs b/Contentstack.Management.Core/Services/Stack/StackShareService.cs
index be81a5a..e9e2d49 100644
--- a/Contentstack.Management.Core/Services/Stack/StackShareService.cs
+++ b/Contentstack.Management.Core/Services/Stack/StackShareService.cs
@@ -1,9 +1,8 @@
 using System;
 using System.Collections.Generic;
-using System.Globalization;
-using System.IO;
+using System.Text.Json;
+using System.Linq;
 using Contentstack.Management.Core.Models;
-using Newtonsoft.Json;
 using Contentstack.Management.Core.Utils;
 
 namespace Contentstack.Management.Core.Services.Stack
@@ -14,7 +13,7 @@ internal class StackShareService : ContentstackService
 
         private string _removeUser;
 
-        internal StackShareService(JsonSerializer serializer, Core.Models.Stack stack) : base(serializer, stack)
+        internal StackShareService(Core.Models.Stack stack, JsonSerializerOptions stjOptions = null) : base(stjOptions ?? new JsonSerializerOptions(), stack)
         {
             if (string.IsNullOrEmpty(stack.APIKey))
             {
@@ -37,40 +36,33 @@ internal void RemoveUsers(string emails)
 
         public override void ContentBody()
         {
-            using (StringWriter stringWriter = new StringWriter(CultureInfo.InvariantCulture))
+            object requestData;
+            
+            if (_invitations != null)
             {
-                JsonWriter writer = new JsonTextWriter(stringWriter);
-                writer.WriteStartObject();
-                if (_invitations != null)
+                requestData = new
                 {
-                    writer.WritePropertyName("emails");
-                    writer.WriteStartArray();
-                    foreach (UserInvitation user in _invitations)
-                        writer.WriteValue(user.Email);
-                    writer.WriteEndArray();
-
-                    writer.WritePropertyName("roles");
-                    writer.WriteStartObject();
-                    foreach (UserInvitation invitation in _invitations)
-                    {
-                        writer.WritePropertyName(invitation.Email);
-                        writer.WriteStartArray();
-                        foreach (string role in invitation.Roles)
-                            writer.WriteValue(role);
-                        writer.WriteEndArray();
-                    }
-                    writer.WriteEndObject();
-                }
-                else if (_removeUser != null)
+                    emails = _invitations.Select(u => u.Email).ToArray(),
+                    roles = _invitations.ToDictionary(
+                        invitation => invitation.Email,
+                        invitation => invitation.Roles.ToArray()
+                    )
+                };
+            }
+            else if (_removeUser != null)
+            {
+                requestData = new
                 {
-                    writer.WritePropertyName("email");
-                    writer.WriteValue(_removeUser);
-                }
-                writer.WriteEndObject();
-
-                string snippet = stringWriter.ToString();
-                this.ByteContent = System.Text.Encoding.UTF8.GetBytes(snippet);
+                    email = _removeUser
+                };
             }
+            else
+            {
+                requestData = new { };
+            }
+
+            string jsonString = JsonSerializer.Serialize(requestData, SerializerOptions);
+            this.ByteContent = System.Text.Encoding.UTF8.GetBytes(jsonString);
         }
     }
 }
diff --git a/Contentstack.Management.Core/Services/Stack/UpdateUserRoleService.cs b/Contentstack.Management.Core/Services/Stack/UpdateUserRoleService.cs
index 3d92b66..b75ec15 100644
--- a/Contentstack.Management.Core/Services/Stack/UpdateUserRoleService.cs
+++ b/Contentstack.Management.Core/Services/Stack/UpdateUserRoleService.cs
@@ -1,10 +1,9 @@
 using System;
 using System.Collections.Generic;
-using System.Globalization;
-using System.IO;
+using System.Text.Json;
+using System.Linq;
 using Contentstack.Management.Core.Models;
 using Contentstack.Management.Core.Queryable;
-using Newtonsoft.Json;
 using Contentstack.Management.Core.Utils;
 
 namespace Contentstack.Management.Core.Services.Stack
@@ -14,8 +13,8 @@ internal class UpdateUserRoleService : ContentstackService
         #region Internal
         private readonly List<UserInvitation> _users;
 
-        internal UpdateUserRoleService(JsonSerializer serializer, Core.Models.Stack stack, List<UserInvitation>userInvitation)
-            : base(serializer, stack)
+        internal UpdateUserRoleService(Core.Models.Stack stack, List<UserInvitation> userInvitation, JsonSerializerOptions stjOptions = null)
+            : base(stjOptions ?? new JsonSerializerOptions(), stack)
         {
             if (userInvitation == null)
             {
@@ -33,25 +32,16 @@ internal UpdateUserRoleService(JsonSerializer serializer, Core.Models.Stack stac
 
         public override void ContentBody()
         {
-            using (StringWriter stringWriter = new StringWriter(CultureInfo.InvariantCulture))
+            var requestData = new
             {
-                JsonWriter writer = new JsonTextWriter(stringWriter);
-                writer.WriteStartObject();
-                writer.WritePropertyName("users");
-                writer.WriteStartObject();
-                foreach (UserInvitation invitation in this._users)
-                {
-                    writer.WritePropertyName(invitation.Uid);
-                    writer.WriteStartArray();
-                    foreach (string role in invitation.Roles)
-                        writer.WriteValue(role);
-                    writer.WriteEndArray();
-                }
-                writer.WriteEndObject();
-                writer.WriteEndObject();
-                string snippet = stringWriter.ToString();
-                this.ByteContent = System.Text.Encoding.UTF8.GetBytes(snippet);
-            }
+                users = _users.ToDictionary(
+                    invitation => invitation.Uid,
+                    invitation => invitation.Roles.ToArray()
+                )
+            };
+
+            string jsonString = JsonSerializer.Serialize(requestData, SerializerOptions);
+            this.ByteContent = System.Text.Encoding.UTF8.GetBytes(jsonString);
         }
         #endregion
     }
diff --git a/Contentstack.Management.Core/Services/User/ForgotPasswordService.cs b/Contentstack.Management.Core/Services/User/ForgotPasswordService.cs
index a87f697..fa24455 100644
--- a/Contentstack.Management.Core/Services/User/ForgotPasswordService.cs
+++ b/Contentstack.Management.Core/Services/User/ForgotPasswordService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 using System.Text.Json;
 using Contentstack.Management.Core.Utils;
diff --git a/Contentstack.Management.Core/Services/User/GetLoggedInUserService.cs b/Contentstack.Management.Core/Services/User/GetLoggedInUserService.cs
index bf8a251..79dd006 100644
--- a/Contentstack.Management.Core/Services/User/GetLoggedInUserService.cs
+++ b/Contentstack.Management.Core/Services/User/GetLoggedInUserService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using Contentstack.Management.Core.Queryable;
 using System.Text.Json;
 
diff --git a/Contentstack.Management.Core/Services/User/LoginService.cs b/Contentstack.Management.Core/Services/User/LoginService.cs
index 006f85c..450a671 100644
--- a/Contentstack.Management.Core/Services/User/LoginService.cs
+++ b/Contentstack.Management.Core/Services/User/LoginService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 using System.Net;
 using System.Text.Json;
diff --git a/Contentstack.Management.Core/Services/User/LogoutService.cs b/Contentstack.Management.Core/Services/User/LogoutService.cs
index de97ded..a199ff9 100644
--- a/Contentstack.Management.Core/Services/User/LogoutService.cs
+++ b/Contentstack.Management.Core/Services/User/LogoutService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Text.Json;
 using Contentstack.Management.Core.Utils;
 
diff --git a/Contentstack.Management.Core/Services/User/ResetPasswordService.cs b/Contentstack.Management.Core/Services/User/ResetPasswordService.cs
index 4db1b4c..c07e6f3 100644
--- a/Contentstack.Management.Core/Services/User/ResetPasswordService.cs
+++ b/Contentstack.Management.Core/Services/User/ResetPasswordService.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 using System.Text.Json;
 using Contentstack.Management.Core.Utils;
diff --git a/Contentstack.Management.Core/contentstack.management.core.csproj b/Contentstack.Management.Core/contentstack.management.core.csproj
index acefc32..ebd9fef 100644
--- a/Contentstack.Management.Core/contentstack.management.core.csproj
+++ b/Contentstack.Management.Core/contentstack.management.core.csproj
@@ -79,13 +79,13 @@
   </ItemGroup>
   
   <ItemGroup>
-    <!-- Temporarily exclude non-core models that reference the old Newtonsoft serializer -->
-    <!-- These will be migrated to System.Text.Json later -->
+    <!-- Re-enable core models for Client, User, Organization, Stack modules -->
+    <!-- Keep other models excluded until later migration phases -->
     <Compile Remove="Models\Asset.cs" />
     <Compile Remove="Models\AssetModel.cs" />
     <Compile Remove="Models\AuditLog.cs" />
     <Compile Remove="Models\BaseModel.cs" />
-    <Compile Remove="Models\BulkOperation.cs" />
+    <!-- BulkOperation.cs - RE-ENABLED -->
     <Compile Remove="Models\ContentModelling.cs" />
     <Compile Remove="Models\ContentType.cs" />
     <Compile Remove="Models\Entry.cs" />
@@ -96,7 +96,7 @@
     <Compile Remove="Models\GlobalField.cs" />
     <Compile Remove="Models\Label.cs" />
     <Compile Remove="Models\Locale.cs" />
-    <Compile Remove="Models\Organization.cs" />
+    <!-- Organization.cs - RE-ENABLED -->
     <Compile Remove="Models\PublishQueue.cs" />
     <Compile Remove="Models\PublishRule.cs" />
     <Compile Remove="Models\Release.cs" />
@@ -104,7 +104,7 @@
     <Compile Remove="Models\Role.cs" />
     <Compile Remove="Models\Taxonomy.cs" />
     <Compile Remove="Models\Term.cs" />
-    <Compile Remove="Models\User.cs" />
+    <!-- User.cs - RE-ENABLED -->
     <Compile Remove="Models\VariantGroup.cs" />
     <Compile Remove="Models\Version.cs" />
     <Compile Remove="Models\Webhook.cs" />
@@ -113,30 +113,27 @@
     <Compile Remove="Models\Fields\**\*.cs" />
     <Compile Remove="Models\Token\**\*.cs" />
     
-    <!-- Temporarily exclude non-core services that haven't been migrated yet -->
+    <!-- Re-enable core services for Client, User, Organization, Stack modules -->
     <Compile Remove="Services\DeleteReleaseItemService.cs" />
     <Compile Remove="Services\QueryService.cs" />
     <Compile Remove="Services\Models\**\*.cs" />
     <Compile Remove="Services\OAuth\**\*.cs" />
-    <Compile Remove="Services\Stack\StackOwnershipService.cs" />
-    <Compile Remove="Services\Stack\StackShareService.cs" />
-    <Compile Remove="Services\Stack\UpdateUserRoleService.cs" />
-    <Compile Remove="Services\Organization\OrgRoles.cs" />
+    <!-- StackOwnershipService.cs, StackShareService.cs, UpdateUserRoleService.cs - RE-ENABLED -->
+    <!-- OrgRoles.cs - RE-ENABLED -->
     
-    <!-- Temporarily exclude services that depend on Stack -->
-    <Compile Remove="Services\Stack\**\*.cs" />
+    <!-- Re-enable Stack services for Stack module -->
+    <!-- Services\Stack\**\*.cs - RE-ENABLED -->
     
-    <!-- Temporarily exclude OAuth handler -->
+    <!-- Keep OAuth handler excluded -->
     <Compile Remove="OAuthHandler.cs" />
     
-    <!-- Temporarily exclude FieldJsonConverter as it depends on Models.Fields namespace -->
+    <!-- Keep FieldJsonConverter excluded -->
     <Compile Remove="Utils\FieldJsonConverter.cs" />
     
-    <!-- Temporarily exclude Stack.cs as it depends on many excluded model types -->
-    <Compile Remove="Models\Stack.cs" />
+    <!-- Stack.cs - RE-ENABLED -->
     
-    <!-- Temporarily exclude Queryable classes that depend on Stack -->
-    <Compile Remove="Queryable\Query.cs" />
+    <!-- Re-enable Query.cs for Stack module -->
+    <!-- Query.cs - RE-ENABLED -->
     <!-- Keep ParameterCollection and QueryParamValue as they're needed by core services -->
     
     <!-- Temporarily exclude ContentstackClient methods that depend on excluded models -->
diff --git a/Directory.Build.props b/Directory.Build.props
index 02afb64..2ad39e3 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -1,5 +1,5 @@
 <Project>
   <PropertyGroup>
-    <Version>1.0.0-beta.1</Version>
+    <Version>1.0.0-beta.2</Version>
   </PropertyGroup>
 </Project>