diff --git a/src/MigrationTools.Clients.TfsObjectModel.Tests/Endpoints/TfsWorkItemEndPointTests.cs b/src/MigrationTools.Clients.TfsObjectModel.Tests/Endpoints/TfsWorkItemEndPointTests.cs
index e73b78b76..fdb7240e0 100644
--- a/src/MigrationTools.Clients.TfsObjectModel.Tests/Endpoints/TfsWorkItemEndPointTests.cs
+++ b/src/MigrationTools.Clients.TfsObjectModel.Tests/Endpoints/TfsWorkItemEndPointTests.cs
@@ -15,6 +15,9 @@
 using MigrationTools.Tools.Interfaces;
 using MigrationTools.Tools.Shadows;
 using MigrationTools.Shadows;
+using Microsoft.Extensions.Configuration;
+using System.IO;
+using System.Text;
 
 namespace MigrationTools.Endpoints.Tests
 {
@@ -97,5 +100,84 @@ protected TfsWorkItemEndpoint GetTfsWorkItemEndPoint(string key = "Source", TfsW
             return (TfsWorkItemEndpoint)services.BuildServiceProvider().GetRequiredKeyedService<IEndpoint>(key);
         }
 
+
+        [TestMethod(), TestCategory("L1")]
+        public void TfsWorkItemEndPoint_EnvironmentOverrideTest()
+        {
+            Environment.SetEnvironmentVariable("MigrationTools__Endpoints__Source__Authentication__AccessToken", "654321");
+            IConfigurationBuilder configBuilder = GetSourceTargetBasicConfig();
+            var configuration = configBuilder.AddEnvironmentVariables().Build();
+            // Create services
+            IServiceCollection serviceCollection = new ServiceCollection();
+            serviceCollection.AddSingleton<EndpointEnricherContainer>();
+            serviceCollection.AddMigrationToolServicesForUnitTests();
+            serviceCollection.AddConfiguredEndpoints(configuration);
+            // Create a service provider from the service collection
+            var serviceProvider = serviceCollection.BuildServiceProvider();
+            var endpoint = serviceProvider.GetKeyedService<IEndpoint>("Source");
+            Assert.IsNotNull(endpoint, "Endpoint not found.");
+            Endpoint<TfsTeamProjectEndpointOptions> endpoint1 = endpoint as Endpoint<TfsTeamProjectEndpointOptions>;
+            // Validate that the correct number of endpoints are registered
+            Assert.AreEqual("654321", endpoint1.Options.Authentication.AccessToken, "Token not passed.");
+
+        }
+
+        private static IConfigurationBuilder GetSourceTargetBasicConfig()
+        {
+            // Create Config
+            var json = @"
+            {
+              ""MigrationTools"": {
+                ""Version"": ""16.0"",
+                ""Endpoints"": {
+                  ""Source"": {
+                    ""EndpointType"": ""TfsTeamProjectEndpoint"",
+                    ""Collection"": ""https://dev.azure.com/nkdagility-preview/"",
+                    ""Project"": ""migrationSource1"",
+                    ""AllowCrossProjectLinking"": false,
+                    ""ReflectedWorkItemIDFieldName"": ""Custom.ReflectedWorkItemId"",
+                    ""Authentication"": {
+                      ""AuthenticationMode"": ""AccessToken"",
+                      ""AccessToken"": ""123456"",
+                      ""NetworkCredentials"": {
+                        ""UserName"": """",
+                        ""Password"": """",
+                        ""Domain"": """"
+                      }
+                    },
+                    ""LanguageMaps"": {
+                      ""AreaPath"": ""Area"",
+                      ""IterationPath"": ""Iteration""
+                    }
+                  },
+                  ""Target"": {
+                    ""EndpointType"": ""TfsTeamProjectEndpoint"",
+                    ""Collection"": ""https://dev.azure.com/nkdagility-preview/"",
+                    ""Project"": ""migrationTest5"",
+                    ""TfsVersion"": ""AzureDevOps"",
+                    ""Authentication"": {
+                      ""AuthenticationMode"": ""AccessToken"",
+                      ""AccessToken"": ""none"",
+                      ""NetworkCredentials"": {
+                        ""UserName"": """",
+                        ""Password"": """",
+                        ""Domain"": """"
+                      }
+                    },
+                    ""ReflectedWorkItemIDFieldName"": ""nkdScrum.ReflectedWorkItemId"",
+                    ""AllowCrossProjectLinking"": false,
+                    ""LanguageMaps"": {
+                      ""AreaPath"": ""Area"",
+                      ""IterationPath"": ""Iteration""
+                    }
+                  }
+                },  
+              }
+            }";
+            var stream = new MemoryStream(Encoding.UTF8.GetBytes(json));
+            var configBuilder = new ConfigurationBuilder().AddJsonStream(new MemoryStream(Encoding.UTF8.GetBytes(json)));
+            return configBuilder;
+        }
+
     }
 }
\ No newline at end of file
diff --git a/src/MigrationTools.Clients.TfsObjectModel/Clients/TfsWorkItemMigrationClient.cs b/src/MigrationTools.Clients.TfsObjectModel/Clients/TfsWorkItemMigrationClient.cs
index 1a5f91a71..95be6bc0e 100644
--- a/src/MigrationTools.Clients.TfsObjectModel/Clients/TfsWorkItemMigrationClient.cs
+++ b/src/MigrationTools.Clients.TfsObjectModel/Clients/TfsWorkItemMigrationClient.cs
@@ -31,7 +31,18 @@ public TfsWorkItemMigrationClient(IOptions<TfsTeamProjectEndpointOptions> option
         {
             _telemetry = telemetry;
             _workItemQueryBuilderFactory = workItemQueryBuilderFactory;
-            InnerConfigure(migrationClient);
+            _bypassRules = WorkItemStoreFlags.BypassRules;
+
+            Lazy<WorkItemStore> _wistore = new Lazy<WorkItemStore>(() =>
+            {
+                Console.WriteLine("Initializing expensive WorkItemStore...");
+                return GetWorkItemStore();
+            });
+            Lazy<ProjectData> _project = new Lazy<ProjectData>(() =>
+            {
+                Console.WriteLine("Initializing expensive ProjectData from WorkItemStore...");
+                return GetProject();
+            });
         }
 
         new TfsTeamProjectEndpointOptions Options => (TfsTeamProjectEndpointOptions)base.Options;
@@ -243,12 +254,7 @@ private Endpoints.IWorkItemQuery GetWorkItemQuery(string WIQLQuery)
             }
         }
 
-        protected void InnerConfigure(IMigrationClient migrationClient, bool bypassRules = true)
-        {
-            _bypassRules = bypassRules ? WorkItemStoreFlags.BypassRules : WorkItemStoreFlags.None;
-            _wistore = GetWorkItemStore();
-            _project = GetProject();
-        }
+ 
 
         public override WorkItemData PersistWorkItem(WorkItemData workItem)
         {
diff --git a/src/MigrationTools.Shadows/Clients/WorkItemQueryBuilderFactoryFake.cs b/src/MigrationTools.Shadows/Clients/WorkItemQueryBuilderFactoryFake.cs
new file mode 100644
index 000000000..2b3a04fdc
--- /dev/null
+++ b/src/MigrationTools.Shadows/Clients/WorkItemQueryBuilderFactoryFake.cs
@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using MigrationTools.Clients;
+
+namespace MigrationTools.Clients.Shadows
+{
+    public class WorkItemQueryBuilderFactoryFake : IWorkItemQueryBuilderFactory
+    {
+        public IWorkItemQueryBuilder Create()
+        {
+            throw new NotImplementedException();
+        }
+    }
+}
diff --git a/src/MigrationTools.Shadows/ServiceCollectionExtensions.cs b/src/MigrationTools.Shadows/ServiceCollectionExtensions.cs
index e8d377aa3..fbdf13c7b 100644
--- a/src/MigrationTools.Shadows/ServiceCollectionExtensions.cs
+++ b/src/MigrationTools.Shadows/ServiceCollectionExtensions.cs
@@ -1,4 +1,6 @@
 using Microsoft.Extensions.DependencyInjection;
+using MigrationTools.Clients;
+using MigrationTools.Clients.Shadows;
 using MigrationTools.Services;
 using MigrationTools.Services.Shadows;
 using Serilog;
@@ -29,6 +31,7 @@ public static void AddMigrationToolServicesForUnitTests(this IServiceCollection
             // Add Telemitery Adapter
             context.AddSingleton<ITelemetryLogger, TelemetryLoggerFake>();
             context.AddSingleton<IMigrationToolVersion, FakeMigrationToolVersion>();
+            context.AddSingleton<IWorkItemQueryBuilderFactory, WorkItemQueryBuilderFactoryFake>();
         }
     }
 }