diff --git a/DI/XDIHelperExtension.cs b/DI/XDIHelperExtension.cs
index a4c2439..528d43f 100644
--- a/DI/XDIHelperExtension.cs
+++ b/DI/XDIHelperExtension.cs
@@ -135,7 +135,7 @@ namespace xDataService.DI
                 if (!isValid)
                 {
                     //
-                    Log("DataService Configuration notProvided ...");
+                    Log("DataService Configuration not provided ...");
                     return;
                 }
 
@@ -176,10 +176,8 @@ namespace xDataService.DI
                         runtimeType: descriptor.Context,
                         args: [
                             source,
-                        descriptor.Provider,
-                        descriptor.ConnectionString,
-                        lifetime,
-                        descriptor.OptionsBuilder
+                            descriptor,
+                            lifetime
                         ]
                     );
 
@@ -213,8 +211,8 @@ namespace xDataService.DI
                             runtimeTypes: runtimeTypes,
                             args: [
                                 source,
-                            r,
-                            lifetime
+                                r,
+                                lifetime
                             ]
                         );
 
diff --git a/Extensions/XDatabaseDescriptorExtensions.cs b/Extensions/XDatabaseDescriptorExtensions.cs
index 779c027..f34bab0 100644
--- a/Extensions/XDatabaseDescriptorExtensions.cs
+++ b/Extensions/XDatabaseDescriptorExtensions.cs
@@ -1,4 +1,5 @@
 using xCommons.Extensions;
+using xDataService.Constants;
 using xDataService.Models;
 
 namespace xDataService.Extensions
@@ -21,6 +22,22 @@ namespace xDataService.Extensions
             return result;
         }
 
+        /// <summary>
+        /// Chack a Descriptor Has Provider or not ...
+        /// </summary>
+        /// <param name="source"></param>
+        /// <returns></returns>
+        public static bool HasProvider(this XDatabaseDescriptor source)
+        {
+            //
+            var result =
+                source.IsValid() &&
+                source.Provider != XDbProviders.None;
+
+            //
+            return result;
+        }
+
         /// <summary>
         /// Check a Descriptor Has EF Core Context or not ...
         /// </summary>
@@ -31,6 +48,8 @@ namespace xDataService.Extensions
             //
             var result =
                 source.IsValid() &&
+                source.HasProvider() &&
+                source.Provider != XDbProviders.MongoDB &&
                 !source.Context.IsNull();
 
             //
@@ -47,11 +66,30 @@ namespace xDataService.Extensions
             //
             var result =
                 source.IsValid() &&
+                source.HasProvider() &&
                 !source.Repositories.IsNull() &&
                 source.Repositories.HasChild();
 
             //
             return result;
         }
+
+        /// <summary>
+        /// Check a Descriptor Has MongoDB Convention Packs ...
+        /// </summary>
+        /// <param name="source"></param>
+        /// <returns></returns>
+        public static bool HasConventionPacks(this XDatabaseDescriptor source)
+        {
+            //
+            var result =
+                source.IsValid() &&
+                source.HasProvider() &&
+                source.Provider == XDbProviders.MongoDB &&
+                !source.ConventionPacks.IsNull();
+
+            //
+            return result;
+        }
     }
 }
\ No newline at end of file
diff --git a/Extensions/XRepositoryDescriptorExtensions.cs b/Extensions/XRepositoryDescriptorExtensions.cs
index aea5029..58eaf16 100644
--- a/Extensions/XRepositoryDescriptorExtensions.cs
+++ b/Extensions/XRepositoryDescriptorExtensions.cs
@@ -65,11 +65,10 @@ namespace xDataService.Extensions
             var result =
                 source.IsValid() &&
                 !source.GraphType.IsNull() &&
+                !source.GraphQuery.IsNull() &&
                 !source.GraphSchema.IsNull() &&
                 !source.GraphTypeKey.IsNull() &&
-                !source.GraphQueryService.IsNull() &&
                 !source.GraphTypeHelperService.IsNull() &&
-                !source.GraphQueryImplementation.IsNull() &&
                 !source.GraphTypeHelperImplementation.IsNull();
 
             //
diff --git a/Helpers/XDataServiceHelper.cs b/Helpers/XDataServiceHelper.cs
index f7338c2..1667f5c 100644
--- a/Helpers/XDataServiceHelper.cs
+++ b/Helpers/XDataServiceHelper.cs
@@ -4,6 +4,8 @@ using GraphQL.Types;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
+using MongoDB.Bson.Serialization;
+using MongoDB.Bson.Serialization.Conventions;
 using MySql.EntityFrameworkCore.Extensions;
 using xCommons.Extensions;
 using xDataService.Constants;
@@ -28,30 +30,27 @@ namespace xDataService.Helpers
         /// Register DbContext ...
         /// </summary>
         /// <param name="source"></param>
-        /// <param name="provider"></param>
-        /// <param name="connectionString"></param>
+        /// <param name="databaseDescriptor"></param>
         /// <param name="lifetime"></param>
-        /// <param name="optionsBuilder"></param>
         /// <typeparam name="TContext"></typeparam>
         public static void AddXDbContext<TContext>(
             IServiceCollection source,
-            XDbProviders provider,
-            string connectionString,
-            ServiceLifetime lifetime = ServiceLifetime.Scoped,
-            Action<dynamic> optionsBuilder = null
+            XDatabaseDescriptor databaseDescriptor,
+            ServiceLifetime lifetime = ServiceLifetime.Scoped
         )
         where TContext : XDbContext
         {
             //
-            if (provider == XDbProviders.None)
+            var isValid =
+                databaseDescriptor.IsValid() &&
+                databaseDescriptor.HasProvider();
+            if (!isValid)
             {
-                //
-                // Log("Invalid Db Provider ...");
-                XException.InvalidArgs.Throw();
+                XException.InvalidConfiguration.Throw();
             }
 
             //
-            switch (provider)
+            switch (databaseDescriptor.Provider)
             {
                 //
                 // MySQL ...
@@ -60,7 +59,11 @@ namespace xDataService.Helpers
                     source.AddEntityFrameworkMySQL();
                     source.AddDbContext<TContext>(cfg =>
                     {
-                        cfg.UseMySQL(connectionString, optionsBuilder);
+                        //
+                        cfg.UseMySQL(
+                            databaseDescriptor.ConnectionString,
+                            databaseDescriptor.OptionsBuilder
+                        );
                     }, lifetime);
                     break;
 
@@ -71,7 +74,11 @@ namespace xDataService.Helpers
                     source.AddEntityFrameworkSqlite();
                     source.AddDbContext<TContext>(cfg =>
                     {
-                        cfg.UseSqlite(connectionString, optionsBuilder);
+                        //
+                        cfg.UseSqlite(
+                            databaseDescriptor.ConnectionString,
+                            databaseDescriptor.OptionsBuilder
+                        );
                     }, lifetime);
                     break;
 
@@ -82,21 +89,70 @@ namespace xDataService.Helpers
                     source.AddEntityFrameworkSqlServer();
                     source.AddDbContext<TContext>(cfg =>
                     {
-                        cfg.UseSqlServer(connectionString, optionsBuilder);
+                        //
+                        cfg.UseSqlServer(
+                            databaseDescriptor.ConnectionString,
+                            databaseDescriptor.OptionsBuilder
+                        );
                     }, lifetime);
                     break;
 
                 //
+                // Mongo DB ...
                 case XDbProviders.MongoDB:
-                    // There is notRequired to Register DBConext forMongo DB ...
+                    //
+                    #region XBaseEntity Mappers ...
+                    //
+                    // Map ID as BsonId here ...
+                    BsonClassMap.RegisterClassMap<XBaseEntity<Guid>>(cm =>
+                    {
+                        //
+                        cm.AutoMap();
+                        cm.MapIdMember(c => c.Id);
+                    });
+                    BsonClassMap.RegisterClassMap<XBaseEntity<int>>(cm =>
+                    {
+                        //
+                        cm.AutoMap();
+                        cm.MapIdMember(c => c.Id);
+                    });
+                    BsonClassMap.RegisterClassMap<XBaseEntity<long>>(cm =>
+                    {
+                        //
+                        cm.AutoMap();
+                        cm.MapIdMember(c => c.Id);
+                    });
+                    BsonClassMap.RegisterClassMap<XBaseEntity<string>>(cm =>
+                    {
+                        //
+                        cm.AutoMap();
+                        cm.MapIdMember(c => c.Id);
+                    });
+                    #endregion
+
+                    //
+                    // Check Has Convention Packs ...
+                    isValid = databaseDescriptor.HasConventionPacks();
+                    if (isValid)
+                    {
+                        //
+                        ConventionRegistry.Register(
+                            nameof(
+                                databaseDescriptor.ConventionPacks
+                            ),
+                            databaseDescriptor.ConventionPacks,
+                            type => !type.FullName
+                            .IsNullOrEmpty()
+                        );
+                    }
                     break;
             }
 
             //
-            var isValid =
-                provider == XDbProviders.MySQL ||
-                provider == XDbProviders.SQLite ||
-                provider == XDbProviders.SQLServer;
+            isValid =
+                databaseDescriptor.Provider == XDbProviders.MySQL ||
+                databaseDescriptor.Provider == XDbProviders.SQLite ||
+                databaseDescriptor.Provider == XDbProviders.SQLServer;
             if (isValid)
             {
                 //
@@ -144,7 +200,12 @@ namespace xDataService.Helpers
         /// <typeparam name="TKeyGeneratorService"></typeparam>
         /// <typeparam name="TKeyGeneratorImplementation"></typeparam>
         /// <returns></returns>
-        public static void AddXRepository<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation>(
+        public static void AddXRepository<
+            TEntity,
+            TKey,
+            TKeyGeneratorService,
+            TKeyGeneratorImplementation
+        >(
             IServiceCollection source,
             XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation> repositoryDescriptor,
             ServiceLifetime lifetime = ServiceLifetime.Scoped
@@ -187,7 +248,14 @@ namespace xDataService.Helpers
         /// <typeparam name="TEventsService"></typeparam>
         /// <typeparam name="TEventsImplementation"></typeparam>
         /// <returns></returns>
-        public static void AddXRepository<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation>(
+        public static void AddXRepository<
+            TEntity,
+            TKey,
+            TKeyGeneratorService,
+            TKeyGeneratorImplementation,
+            TEventsService,
+            TEventsImplementation
+        >(
             IServiceCollection source,
             XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation> repositoryDescriptor,
             ServiceLifetime lifetime = ServiceLifetime.Scoped
@@ -246,15 +314,27 @@ namespace xDataService.Helpers
         /// <typeparam name="TEventsImplementation"></typeparam>
         /// <typeparam name="TGraph"></typeparam>
         /// <typeparam name="TGraphKey"></typeparam>
-        /// <typeparam name="TGraphQueryService"></typeparam>
-        /// <typeparam name="TGraphQueryImplementation"></typeparam>
+        /// <typeparam name="TGraphQuery"></typeparam>
         /// <typeparam name="TGraphTypeHelperService"></typeparam>
         /// <typeparam name="TGraphTypeHelperImplementation"></typeparam>
         /// <typeparam name="TGraphSchema"></typeparam>
         /// <returns></returns>
-        public static void AddXRepository<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
+        public static void AddXRepository<
+            TEntity,
+            TKey,
+            TKeyGeneratorService,
+            TKeyGeneratorImplementation,
+            TEventsService,
+            TEventsImplementation,
+            TGraph,
+            TGraphKey,
+            TGraphQuery,
+            TGraphTypeHelperService,
+            TGraphTypeHelperImplementation,
+            TGraphSchema
+        >(
             IServiceCollection source,
-            XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema> repositoryDescriptor,
+            XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema> repositoryDescriptor,
             ServiceLifetime lifetime = ServiceLifetime.Scoped
         )
         where TGraphSchema : Schema
@@ -266,9 +346,8 @@ namespace xDataService.Helpers
         where TEventsImplementation : XBaseRepositoryEvents<TEntity>
         where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
         where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+        where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-        where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-        where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         {
             //
             var isValid = repositoryDescriptor.IsValid();
@@ -309,7 +388,7 @@ namespace xDataService.Helpers
             if (isValid)
             {
                 //
-                AddXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
+                AddXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
                     source,
                     repositoryDescriptor,
                     lifetime
@@ -331,17 +410,31 @@ namespace xDataService.Helpers
         /// <typeparam name="TEventsImplementation"></typeparam>
         /// <typeparam name="TGraph"></typeparam>
         /// <typeparam name="TGraphKey"></typeparam>
-        /// <typeparam name="TGraphQueryService"></typeparam>
-        /// <typeparam name="TGraphQueryImplementation"></typeparam>
+        /// <typeparam name="TGraphQuery"></typeparam>
         /// <typeparam name="TGraphTypeHelperService"></typeparam>
         /// <typeparam name="TGraphTypeHelperImplementation"></typeparam>
         /// <typeparam name="TGraphSchema"></typeparam>
         /// <typeparam name="TRepositoryService"></typeparam>
         /// <typeparam name="TRepositoryImplementation"></typeparam>
         /// <returns></returns>
-        public static void AddXRepository<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation>(
+        public static void AddXRepository<
+            TEntity,
+            TKey,
+            TKeyGeneratorService,
+            TKeyGeneratorImplementation,
+            TEventsService,
+            TEventsImplementation,
+            TGraph,
+            TGraphKey,
+            TGraphQuery,
+            TGraphTypeHelperService,
+            TGraphTypeHelperImplementation,
+            TGraphSchema,
+            TRepositoryService,
+            TRepositoryImplementation
+        >(
             IServiceCollection source,
-            XInMemoryRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation> repositoryDescriptor,
+            XInMemoryRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation> repositoryDescriptor,
             ServiceLifetime lifetime = ServiceLifetime.Scoped
         )
         where TGraphSchema : Schema
@@ -354,10 +447,9 @@ namespace xDataService.Helpers
         where TEventsImplementation : XBaseRepositoryEvents<TEntity>
         where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
         where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+        where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         where TRepositoryImplementation : XBaseInMemoryRepositoy<TEntity, TKey>
         where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-        where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-        where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         {
             //
             var isValid = repositoryDescriptor.IsValid();
@@ -398,7 +490,7 @@ namespace xDataService.Helpers
             if (isValid)
             {
                 //
-                AddXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
+                AddXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
                     source,
                     repositoryDescriptor,
                     lifetime
@@ -435,17 +527,31 @@ namespace xDataService.Helpers
         /// <typeparam name="TEventsImplementation"></typeparam>
         /// <typeparam name="TGraph"></typeparam>
         /// <typeparam name="TGraphKey"></typeparam>
-        /// <typeparam name="TGraphQueryService"></typeparam>
-        /// <typeparam name="TGraphQueryImplementation"></typeparam>
+        /// <typeparam name="TGraphQuery"></typeparam>
         /// <typeparam name="TGraphTypeHelperService"></typeparam>
         /// <typeparam name="TGraphTypeHelperImplementation"></typeparam>
         /// <typeparam name="TGraphSchema"></typeparam>
         /// <typeparam name="TRepositoryService"></typeparam>
         /// <typeparam name="TRepositoryImplementation"></typeparam>
         /// <returns></returns>
-        public static void AddXRepository<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation>(
+        public static void AddXRepository<
+            TEntity,
+            TKey,
+            TKeyGeneratorService,
+            TKeyGeneratorImplementation,
+            TEventsService,
+            TEventsImplementation,
+            TGraph,
+            TGraphKey,
+            TGraphQuery,
+            TGraphTypeHelperService,
+            TGraphTypeHelperImplementation,
+            TGraphSchema,
+            TRepositoryService,
+            TRepositoryImplementation
+        >(
             IServiceCollection source,
-            XMongoRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation> repositoryDescriptor,
+            XMongoRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation> repositoryDescriptor,
             ServiceLifetime lifetime = ServiceLifetime.Scoped
         )
         where TGraphSchema : Schema
@@ -457,11 +563,10 @@ namespace xDataService.Helpers
         where TRepositoryService : IXBaseRepository<TEntity, TKey>
         where TEventsImplementation : XBaseRepositoryEvents<TEntity>
         where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
-        where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
         where TRepositoryImplementation : XBaseMongoRepository<TEntity, TKey>
+        where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+        where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-        where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-        where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         {
             //
             var isValid = repositoryDescriptor.IsValid();
@@ -502,7 +607,7 @@ namespace xDataService.Helpers
             if (isValid)
             {
                 //
-                AddXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
+                AddXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
                     source,
                     repositoryDescriptor,
                     lifetime
@@ -539,8 +644,7 @@ namespace xDataService.Helpers
         /// <typeparam name="TEventsImplementation"></typeparam>
         /// <typeparam name="TGraph"></typeparam>
         /// <typeparam name="TGraphKey"></typeparam>
-        /// <typeparam name="TGraphQueryService"></typeparam>
-        /// <typeparam name="TGraphQueryImplementation"></typeparam>
+        /// <typeparam name="TGraphQuery"></typeparam>
         /// <typeparam name="TGraphTypeHelperService"></typeparam>
         /// <typeparam name="TGraphTypeHelperImplementation"></typeparam>
         /// <typeparam name="TGraphSchema"></typeparam>
@@ -548,9 +652,25 @@ namespace xDataService.Helpers
         /// <typeparam name="TRepositoryImplementation"></typeparam>
         /// <typeparam name="TContext"></typeparam>
         /// <returns></returns>
-        public static void AddXRepository<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation, TContext>(
+        public static void AddXRepository<
+            TEntity,
+            TKey,
+            TKeyGeneratorService,
+            TKeyGeneratorImplementation,
+            TEventsService,
+            TEventsImplementation,
+            TGraph,
+            TGraphKey,
+            TGraphQuery,
+            TGraphTypeHelperService,
+            TGraphTypeHelperImplementation,
+            TGraphSchema,
+            TRepositoryService,
+            TRepositoryImplementation,
+            TContext
+        >(
             IServiceCollection source,
-            XEFRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation, TContext> repositoryDescriptor,
+            XEFRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation, TContext> repositoryDescriptor,
             ServiceLifetime lifetime = ServiceLifetime.Scoped
         )
         where TGraphSchema : Schema
@@ -564,10 +684,9 @@ namespace xDataService.Helpers
         where TEventsImplementation : XBaseRepositoryEvents<TEntity>
         where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
         where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+        where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         where TRepositoryImplementation : XBaseEFRepository<TEntity, TKey, TContext>
         where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-        where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-        where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         {
             //
             var isValid = repositoryDescriptor.IsValid();
@@ -608,7 +727,7 @@ namespace xDataService.Helpers
             if (isValid)
             {
                 //
-                AddXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
+                AddXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
                     source,
                     repositoryDescriptor,
                     lifetime
@@ -645,17 +764,31 @@ namespace xDataService.Helpers
         /// <typeparam name="TEventsImplementation"></typeparam>
         /// <typeparam name="TGraph"></typeparam>
         /// <typeparam name="TGraphKey"></typeparam>
-        /// <typeparam name="TGraphQueryService"></typeparam>
-        /// <typeparam name="TGraphQueryImplementation"></typeparam>
+        /// <typeparam name="TGraphQuery"></typeparam>
         /// <typeparam name="TGraphTypeHelperService"></typeparam>
         /// <typeparam name="TGraphTypeHelperImplementation"></typeparam>
         /// <typeparam name="TGraphSchema"></typeparam>
         /// <typeparam name="TRepositoryService"></typeparam>
         /// <typeparam name="TRepositoryImplementation"></typeparam>
         /// <returns></returns>
-        public static void UseXRepository<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation>(
+        public static void UseXRepository<
+            TEntity,
+            TKey,
+            TKeyGeneratorService,
+            TKeyGeneratorImplementation,
+            TEventsService,
+            TEventsImplementation,
+            TGraph,
+            TGraphKey,
+            TGraphQuery,
+            TGraphTypeHelperService,
+            TGraphTypeHelperImplementation,
+            TGraphSchema,
+            TRepositoryService,
+            TRepositoryImplementation
+        >(
             IApplicationBuilder source,
-            XInMemoryRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation> repositoryDescriptor
+            XInMemoryRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation> repositoryDescriptor
         )
         where TGraphSchema : Schema
         where TGraphKey : IGraphType
@@ -668,9 +801,8 @@ namespace xDataService.Helpers
         where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
         where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
         where TRepositoryImplementation : XBaseInMemoryRepositoy<TEntity, TKey>
+        where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-        where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-        where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         {
             //
             var isValid = repositoryDescriptor.IsValid();
@@ -685,7 +817,7 @@ namespace xDataService.Helpers
             if (isValid)
             {
                 //
-                UseXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
+                UseXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
                     source,
                     repositoryDescriptor
                 );
@@ -706,17 +838,31 @@ namespace xDataService.Helpers
         /// <typeparam name="TEventsImplementation"></typeparam>
         /// <typeparam name="TGraph"></typeparam>
         /// <typeparam name="TGraphKey"></typeparam>
-        /// <typeparam name="TGraphQueryService"></typeparam>
-        /// <typeparam name="TGraphQueryImplementation"></typeparam>
+        /// <typeparam name="TGraphQuery"></typeparam>
         /// <typeparam name="TGraphTypeHelperService"></typeparam>
         /// <typeparam name="TGraphTypeHelperImplementation"></typeparam>
         /// <typeparam name="TGraphSchema"></typeparam>
         /// <typeparam name="TRepositoryService"></typeparam>
         /// <typeparam name="TRepositoryImplementation"></typeparam>
         /// <returns></returns>
-        public static void UseXRepository<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation>(
+        public static void UseXRepository<
+            TEntity,
+            TKey,
+            TKeyGeneratorService,
+            TKeyGeneratorImplementation,
+            TEventsService,
+            TEventsImplementation,
+            TGraph,
+            TGraphKey,
+            TGraphQuery,
+            TGraphTypeHelperService,
+            TGraphTypeHelperImplementation,
+            TGraphSchema,
+            TRepositoryService,
+            TRepositoryImplementation
+        >(
             IApplicationBuilder source,
-            XMongoRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation> repositoryDescriptor
+            XMongoRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation> repositoryDescriptor
         )
         where TGraphSchema : Schema
         where TGraphKey : IGraphType
@@ -727,11 +873,10 @@ namespace xDataService.Helpers
         where TRepositoryService : IXBaseRepository<TEntity, TKey>
         where TEventsImplementation : XBaseRepositoryEvents<TEntity>
         where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
-        where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
         where TRepositoryImplementation : XBaseMongoRepository<TEntity, TKey>
+        where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+        where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-        where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-        where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         {
             //
             var isValid = repositoryDescriptor.IsValid();
@@ -746,7 +891,7 @@ namespace xDataService.Helpers
             if (isValid)
             {
                 //
-                UseXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
+                UseXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
                     source,
                     repositoryDescriptor
                 );
@@ -766,8 +911,7 @@ namespace xDataService.Helpers
         /// <typeparam name="TEventsImplementation"></typeparam>
         /// <typeparam name="TGraph"></typeparam>
         /// <typeparam name="TGraphKey"></typeparam>
-        /// <typeparam name="TGraphQueryService"></typeparam>
-        /// <typeparam name="TGraphQueryImplementation"></typeparam>
+        /// <typeparam name="TGraphQuery"></typeparam>
         /// <typeparam name="TGraphTypeHelperService"></typeparam>
         /// <typeparam name="TGraphTypeHelperImplementation"></typeparam>
         /// <typeparam name="TGraphSchema"></typeparam>
@@ -775,9 +919,25 @@ namespace xDataService.Helpers
         /// <typeparam name="TRepositoryImplementation"></typeparam>
         /// <typeparam name="TContext"></typeparam>
         /// <returns></returns>
-        public static void UseXRepository<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation, TContext>(
+        public static void UseXRepository<
+            TEntity,
+            TKey,
+            TKeyGeneratorService,
+            TKeyGeneratorImplementation,
+            TEventsService,
+            TEventsImplementation,
+            TGraph,
+            TGraphKey,
+            TGraphQuery,
+            TGraphTypeHelperService,
+            TGraphTypeHelperImplementation,
+            TGraphSchema,
+            TRepositoryService,
+            TRepositoryImplementation,
+            TContext
+        >(
             IApplicationBuilder source,
-            XEFRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation, TContext> repositoryDescriptor
+            XEFRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation, TContext> repositoryDescriptor
         )
         where TGraphSchema : Schema
         where TContext : XDbContext
@@ -790,10 +950,9 @@ namespace xDataService.Helpers
         where TEventsImplementation : XBaseRepositoryEvents<TEntity>
         where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
         where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+        where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         where TRepositoryImplementation : XBaseEFRepository<TEntity, TKey, TContext>
         where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-        where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-        where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         {
             //
             var isValid = repositoryDescriptor.IsValid();
@@ -808,7 +967,7 @@ namespace xDataService.Helpers
             if (isValid)
             {
                 //
-                UseXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
+                UseXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQuery, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
                     source,
                     repositoryDescriptor
                 );
@@ -851,7 +1010,12 @@ namespace xDataService.Helpers
         /// <typeparam name="TKeyGeneratorService"></typeparam>
         /// <typeparam name="TKeyGeneratorImplementation"></typeparam>
         /// <returns></returns>
-        public static void AddXKeyGenerator<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation>(
+        public static void AddXKeyGenerator<
+            TEntity,
+            TKey,
+            TKeyGeneratorService,
+            TKeyGeneratorImplementation
+        >(
             IServiceCollection source,
             XRepositoryDescriptor<TEntity, TKey> repositoryDescriptor,
             ServiceLifetime lifetime = ServiceLifetime.Scoped
@@ -894,7 +1058,12 @@ namespace xDataService.Helpers
         /// <typeparam name="TEventsService"></typeparam>
         /// <typeparam name="TEventsImplementation"></typeparam>
         /// <returns></returns>
-        public static void AddXEvents<TEntity, TKey, TEventsService, TEventsImplementation>(
+        public static void AddXEvents<
+            TEntity,
+            TKey,
+            TEventsService,
+            TEventsImplementation
+        >(
             IServiceCollection source,
             XRepositoryDescriptor<TEntity, TKey> repositoryDescriptor,
             ServiceLifetime lifetime = ServiceLifetime.Scoped
@@ -936,13 +1105,21 @@ namespace xDataService.Helpers
         /// <typeparam name="TKey"></typeparam>
         /// <typeparam name="TGraph"></typeparam>
         /// <typeparam name="TGraphKey"></typeparam>
-        /// <typeparam name="TGraphQueryService"></typeparam>
-        /// <typeparam name="TGraphQueryImplementation"></typeparam>
+        /// <typeparam name="TGraphQuery"></typeparam>
         /// <typeparam name="TGraphTypeHelperService"></typeparam>
         /// <typeparam name="TGraphTypeHelperImplementation"></typeparam>
         /// <typeparam name="TGraphSchema"></typeparam>
         /// <returns></returns>
-        public static void AddXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
+        public static void AddXGraphQL<
+            TEntity,
+            TKey,
+            TGraph,
+            TGraphKey,
+            TGraphQuery,
+            TGraphTypeHelperService,
+            TGraphTypeHelperImplementation,
+            TGraphSchema
+        >(
             IServiceCollection source,
             XRepositoryDescriptor<TEntity, TKey> repositoryDescriptor,
             ServiceLifetime lifetime = ServiceLifetime.Scoped
@@ -952,9 +1129,8 @@ namespace xDataService.Helpers
         where TEntity : XBaseEntity<TKey>
         where TGraph : XBaseGraphObjectType<TEntity, TKey>
         where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+        where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-        where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-        where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         {
             //
             // Validate ...
@@ -962,32 +1138,16 @@ namespace xDataService.Helpers
                 !source.IsNull() &&
                 !repositoryDescriptor.IsNull() &&
                 !repositoryDescriptor.GraphType.IsNull() &&
+                !repositoryDescriptor.GraphQuery.IsNull() &&
                 !repositoryDescriptor.GraphSchema.IsNull() &&
                 !repositoryDescriptor.GraphTypeKey.IsNull() &&
-                !repositoryDescriptor.GraphQueryService.IsNull() &&
                 !repositoryDescriptor.GraphTypeHelperService.IsNull() &&
-                !repositoryDescriptor.GraphQueryImplementation.IsNull() &&
                 !repositoryDescriptor.GraphTypeHelperImplementation.IsNull();
             if (!isValid)
             {
                 return;
             }
 
-            //
-            // Register Graph Type ...
-            var builder = source.GetRegisteredService<IGraphQLBuilder>();
-            if (builder.IsNull())
-            {
-                //
-                Action<GraphQLOptions> options = x => { };
-                builder = source.AddGraphQL(options)
-                    .AddNewtonsoftJson(deserializerSettings => { }, serializerSettings => { })
-                    .AddWebSockets()
-                    .AddDataLoader()
-                    .AddGraphTypes();
-            }
-            builder.AddGraphTypes(repositoryDescriptor.GraphType);
-
             //
             // Register Graph Schema ...
             source.Add(
@@ -1002,8 +1162,8 @@ namespace xDataService.Helpers
             // Register Graph Query ...
             source.Add(
                 new ServiceDescriptor(
-                    repositoryDescriptor.GraphQueryService,
-                    repositoryDescriptor.GraphQueryImplementation,
+                    repositoryDescriptor.GraphQuery,
+                    repositoryDescriptor.GraphQuery,
                     lifetime
                 )
             );
@@ -1017,6 +1177,41 @@ namespace xDataService.Helpers
                     lifetime: ServiceLifetime.Singleton
                 )
             );
+
+            //
+            // Register Graph Type ...
+            source.Add(
+                new ServiceDescriptor(
+                    repositoryDescriptor.GraphType,
+                    repositoryDescriptor.GraphType,
+                    ServiceLifetime.Singleton
+                )
+            );
+
+            //
+            // Register Graph Events ...
+            source.Add(
+                new ServiceDescriptor(
+                    typeof(XBaseGraphQLEventType<TEntity, TKey, TGraph>),
+                    typeof(XBaseGraphQLEventType<TEntity, TKey, TGraph>),
+                    ServiceLifetime.Singleton
+                )
+            );
+
+            //
+            // Register Graph Type Schema ...
+            var builder = source.GetRegisteredService<IGraphQLBuilder>();
+            if (builder.IsNull())
+            {
+                //
+                Action<GraphQLOptions> options = x => { };
+                builder = source.AddGraphQL(options)
+                    .AddNewtonsoftJson(deserializerSettings => { }, serializerSettings => { })
+                    .AddWebSockets()
+                    .AddDataLoader()
+                    .AddGraphTypes();
+            }
+            builder.AddGraphTypes(repositoryDescriptor.GraphSchema);
         }
 
         /// <summary>
@@ -1029,13 +1224,21 @@ namespace xDataService.Helpers
         /// <typeparam name="TKey"></typeparam>
         /// <typeparam name="TGraph"></typeparam>
         /// <typeparam name="TGraphKey"></typeparam>
-        /// <typeparam name="TGraphQueryService"></typeparam>
-        /// <typeparam name="TGraphQueryImplementation"></typeparam>
+        /// <typeparam name="TGraphQuery"></typeparam>
         /// <typeparam name="TGraphTypeHelperService"></typeparam>
         /// <typeparam name="TGraphTypeHelperImplementation"></typeparam>
         /// <typeparam name="TGraphSchema"></typeparam>
         /// <returns></returns>
-        public static void UseXGraphQL<TEntity, TKey, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>(
+        public static void UseXGraphQL<
+            TEntity,
+            TKey,
+            TGraph,
+            TGraphKey,
+            TGraphQuery,
+            TGraphTypeHelperService,
+            TGraphTypeHelperImplementation,
+            TGraphSchema
+        >(
             IApplicationBuilder source,
             XRepositoryDescriptor<TEntity, TKey> repositoryDescriptor
         )
@@ -1044,9 +1247,8 @@ namespace xDataService.Helpers
         where TEntity : XBaseEntity<TKey>
         where TGraph : XBaseGraphObjectType<TEntity, TKey>
         where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+        where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-        where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-        where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
         {
             //
             // Validate ...
@@ -1054,11 +1256,10 @@ namespace xDataService.Helpers
                 !source.IsNull() &&
                 !repositoryDescriptor.IsNull() &&
                 !repositoryDescriptor.GraphType.IsNull() &&
+                !repositoryDescriptor.GraphQuery.IsNull() &&
                 !repositoryDescriptor.GraphSchema.IsNull() &&
                 !repositoryDescriptor.GraphTypeKey.IsNull() &&
-                !repositoryDescriptor.GraphQueryService.IsNull() &&
                 !repositoryDescriptor.GraphTypeHelperService.IsNull() &&
-                !repositoryDescriptor.GraphQueryImplementation.IsNull() &&
                 !repositoryDescriptor.GraphTypeHelperImplementation.IsNull();
             if (!isValid)
             {
diff --git a/Models/XRepositoryDescriptor.cs b/Models/XRepositoryDescriptor.cs
index 6fc01f7..48ed6e3 100644
--- a/Models/XRepositoryDescriptor.cs
+++ b/Models/XRepositoryDescriptor.cs
@@ -69,13 +69,7 @@ namespace xDataService.Models
         /// Entity GrapQL Query ...
         /// </summary>
         /// <value></value>
-        public Type GraphQueryService { get; set; } = null;
-
-        /// <summary>
-        /// Entity GrapQL Query ...
-        /// </summary>
-        /// <value></value>
-        public Type GraphQueryImplementation { get; set; } = null;
+        public Type GraphQuery { get; set; } = null;
 
         /// <summary>
         /// Repository Event Provider ...
@@ -133,7 +127,12 @@ namespace xDataService.Models
     /// <summary>
     /// a Repository Descriptor ...
     /// </summary>
-    public class XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation> : XRepositoryDescriptor<TEntity, TKey>
+    public class XRepositoryDescriptor<
+        TEntity, 
+        TKey, 
+        TKeyGeneratorService, 
+        TKeyGeneratorImplementation
+    > : XRepositoryDescriptor<TEntity, TKey>
     where TEntity : XBaseEntity<TKey>
     where TKeyGeneratorService : IXKeyGenerator<TEntity, TKey>
     where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
@@ -149,7 +148,19 @@ namespace xDataService.Models
     /// <summary>
     /// a Repository Descriptor ...
     /// </summary>
-    public class XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation> : XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation>
+    public class XRepositoryDescriptor<
+        TEntity, 
+        TKey, 
+        TKeyGeneratorService, 
+        TKeyGeneratorImplementation, 
+        TEventsService, 
+        TEventsImplementation
+    > : XRepositoryDescriptor<
+        TEntity, 
+        TKey, 
+        TKeyGeneratorService, 
+        TKeyGeneratorImplementation
+    >
     where TEntity : XBaseEntity<TKey>
     where TEventsService : IXBaseRepositoryEvents<TEntity>
     where TKeyGeneratorService : IXKeyGenerator<TEntity, TKey>
@@ -167,7 +178,27 @@ namespace xDataService.Models
     /// <summary>
     /// a Repository Descriptor ...
     /// </summary>
-    public class XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema> : XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation>
+    public class XRepositoryDescriptor<
+        TEntity, 
+        TKey, 
+        TKeyGeneratorService, 
+        TKeyGeneratorImplementation, 
+        TEventsService, 
+        TEventsImplementation, 
+        TGraph, 
+        TGraphKey, 
+        TGraphQuery, 
+        TGraphTypeHelperService, 
+        TGraphTypeHelperImplementation, 
+        TGraphSchema
+    > : XRepositoryDescriptor<
+        TEntity, 
+        TKey, 
+        TKeyGeneratorService, 
+        TKeyGeneratorImplementation, 
+        TEventsService, 
+        TEventsImplementation
+    >
     where TGraphSchema : Schema
     where TGraphKey : IGraphType
     where TEntity : XBaseEntity<TKey>
@@ -177,19 +208,17 @@ namespace xDataService.Models
     where TEventsImplementation : XBaseRepositoryEvents<TEntity>
     where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
     where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+    where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
     where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-    where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-    where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
     {
         public XRepositoryDescriptor() : base()
         {
             //
             GraphType = typeof(TGraph);
             GraphTypeKey = typeof(TGraphKey);
+            GraphQuery = typeof(TGraphQuery);
             GraphSchema = typeof(TGraphSchema);
-            GraphQueryService = typeof(TGraphQueryService);
             GraphTypeHelperService = typeof(TGraphTypeHelperService);
-            GraphQueryImplementation = typeof(TGraphQueryImplementation);
             GraphTypeHelperImplementation = typeof(TGraphTypeHelperImplementation);
         }
     }
@@ -197,7 +226,35 @@ namespace xDataService.Models
     /// <summary>
     /// a Repository Descriptor ...
     /// </summary>
-    public class XInMemoryRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation> : XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>
+    public class XInMemoryRepositoryDescriptor<
+        TEntity, 
+        TKey, 
+        TKeyGeneratorService, 
+        TKeyGeneratorImplementation, 
+        TEventsService, 
+        TEventsImplementation, 
+        TGraph, 
+        TGraphKey, 
+        TGraphQuery, 
+        TGraphTypeHelperService, 
+        TGraphTypeHelperImplementation, 
+        TGraphSchema, 
+        TRepositoryService, 
+        TRepositoryImplementation
+    > : XRepositoryDescriptor<
+        TEntity, 
+        TKey, 
+        TKeyGeneratorService, 
+        TKeyGeneratorImplementation, 
+        TEventsService, 
+        TEventsImplementation, 
+        TGraph, 
+        TGraphKey, 
+        TGraphQuery, 
+        TGraphTypeHelperService, 
+        TGraphTypeHelperImplementation, 
+        TGraphSchema
+    >
     where TGraphSchema : Schema
     where TGraphKey : IGraphType
     where TEntity : XBaseEntity<TKey>
@@ -209,9 +266,8 @@ namespace xDataService.Models
     where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
     where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
     where TRepositoryImplementation : XBaseInMemoryRepositoy<TEntity, TKey>
+    where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
     where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-    where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-    where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
     {
         public XInMemoryRepositoryDescriptor() : base()
         {
@@ -224,7 +280,35 @@ namespace xDataService.Models
     /// <summary>
     /// a Repository Descriptor ...
     /// </summary>
-    public class XMongoRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation> : XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>
+    public class XMongoRepositoryDescriptor<
+        TEntity, 
+        TKey, 
+        TKeyGeneratorService, 
+        TKeyGeneratorImplementation, 
+        TEventsService, 
+        TEventsImplementation, 
+        TGraph, 
+        TGraphKey, 
+        TGraphQuery, 
+        TGraphTypeHelperService, 
+        TGraphTypeHelperImplementation, 
+        TGraphSchema, 
+        TRepositoryService, 
+        TRepositoryImplementation
+    > : XRepositoryDescriptor<
+        TEntity, 
+        TKey, 
+        TKeyGeneratorService, 
+        TKeyGeneratorImplementation, 
+        TEventsService, 
+        TEventsImplementation, 
+        TGraph, 
+        TGraphKey, 
+        TGraphQuery, 
+        TGraphTypeHelperService, 
+        TGraphTypeHelperImplementation, 
+        TGraphSchema
+    >
     where TGraphSchema : Schema
     where TGraphKey : IGraphType
     where TEntity : XBaseEntity<TKey>
@@ -236,9 +320,8 @@ namespace xDataService.Models
     where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
     where TRepositoryImplementation : XBaseMongoRepository<TEntity, TKey>
     where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+    where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
     where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-    where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-    where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
     {
         public XMongoRepositoryDescriptor() : base()
         {
@@ -251,7 +334,36 @@ namespace xDataService.Models
     /// <summary>
     /// a Repository Descriptor ...
     /// </summary>
-    public class XEFRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema, TRepositoryService, TRepositoryImplementation, TContext> : XRepositoryDescriptor<TEntity, TKey, TKeyGeneratorService, TKeyGeneratorImplementation, TEventsService, TEventsImplementation, TGraph, TGraphKey, TGraphQueryService, TGraphQueryImplementation, TGraphTypeHelperService, TGraphTypeHelperImplementation, TGraphSchema>
+    public class XEFRepositoryDescriptor<
+        TEntity,
+        TKey,
+        TKeyGeneratorService,
+        TKeyGeneratorImplementation,
+        TEventsService,
+        TEventsImplementation,
+        TGraph,
+        TGraphKey,
+        TGraphQuery,
+        TGraphTypeHelperService,
+        TGraphTypeHelperImplementation,
+        TGraphSchema,
+        TRepositoryService,
+        TRepositoryImplementation,
+        TContext
+    > : XRepositoryDescriptor<
+        TEntity,
+        TKey,
+        TKeyGeneratorService,
+        TKeyGeneratorImplementation,
+        TEventsService,
+        TEventsImplementation, 
+        TGraph, 
+        TGraphKey, 
+        TGraphQuery, 
+        TGraphTypeHelperService, 
+        TGraphTypeHelperImplementation, 
+        TGraphSchema
+    >
     where TGraphSchema : Schema
     where TContext : XDbContext
     where TGraphKey : IGraphType
@@ -263,10 +375,9 @@ namespace xDataService.Models
     where TEventsImplementation : XBaseRepositoryEvents<TEntity>
     where TKeyGeneratorImplementation : XKeyGenerator<TEntity, TKey>
     where TGraphTypeHelperService : IXBaseGraphQLTypeHelper<TEntity, TKey>
+    where TGraphQuery : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
     where TRepositoryImplementation : XBaseEFRepository<TEntity, TKey, TContext>
     where TGraphTypeHelperImplementation : XBaseGraphQLTypeHelper<TEntity, TKey>
-    where TGraphQueryService : IXBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
-    where TGraphQueryImplementation : XBaseGraphQLQuery<TEntity, TKey, TGraph, TGraphKey>
     {
         public XEFRepositoryDescriptor() : base()
         {
diff --git a/Providers/XLongKeyGenerator.cs b/Providers/XLongKeyGenerator.cs
new file mode 100644
index 0000000..3efc073
--- /dev/null
+++ b/Providers/XLongKeyGenerator.cs
@@ -0,0 +1,45 @@
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using xCommons.Extensions;
+using xDataService.Extensions;
+using xDataService.Interfaces;
+using xModels.Base;
+
+namespace xDataService.Providers
+{
+    /// <summary>
+    /// Default Long Key Generator ...
+    /// </summary>
+    /// <typeparam name="TEntity"></typeparam>    
+    public class XLongKeyGenerator<TEntity> : XKeyGenerator<TEntity, long>, IXKeyGenerator<TEntity, long>
+    where TEntity : XBaseEntity<long>
+    {
+        public override async Task<long> GenerateKey(
+            IXBaseRepository<TEntity, long> repository,
+            CancellationToken cancellationToken = default
+        )
+        {
+            //
+            var items = (await repository.GetAllAsync())
+                .OrderByDescending(nameof(XBaseEntity<long>.Id));
+            var last = items
+                .FirstOrDefault();
+
+            //
+            var result = last.IsNull() ? 1 : last.Id + 1;
+
+            //
+            return result;
+        }
+
+        public override bool IsEmpty(long id)
+        {
+            //
+            var result = id <= 0;
+
+            //
+            return result;
+        }
+    }
+}
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