diff --git a/tests/Trax.Effect.Tests.Integration/UnitTests/Attributes/InjectAttributeTests.cs b/tests/Trax.Effect.Tests.Integration/UnitTests/Attributes/InjectAttributeTests.cs
new file mode 100644
index 0000000..26fff2e
--- /dev/null
+++ b/tests/Trax.Effect.Tests.Integration/UnitTests/Attributes/InjectAttributeTests.cs
@@ -0,0 +1,82 @@
+using System.Reflection;
+using FluentAssertions;
+using Microsoft.Extensions.DependencyInjection;
+using Trax.Effect.Attributes;
+using Trax.Effect.Extensions;
+
+namespace Trax.Effect.Tests.Integration.UnitTests.Attributes;
+
+[TestFixture]
+public class InjectAttributeTests
+{
+    [Test]
+    public void InjectAttribute_CanBeAppliedToProperty()
+    {
+        // Arrange & Act
+        var property = typeof(TestInjectable).GetProperty(nameof(TestInjectable.InjectedService));
+        var attribute = property?.GetCustomAttribute<InjectAttribute>();
+
+        // Assert
+        attribute.Should().NotBeNull();
+    }
+
+    [Test]
+    public void InjectAttribute_TargetsPropertyOnly()
+    {
+        // Arrange & Act
+        var attributeUsage = typeof(InjectAttribute).GetCustomAttribute<AttributeUsageAttribute>();
+
+        // Assert
+        attributeUsage.Should().NotBeNull();
+        attributeUsage!.ValidOn.Should().Be(AttributeTargets.Property);
+    }
+
+    [Test]
+    public void InjectProperties_SetsMarkedProperties()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        services.AddSingleton<ITestService>(new TestService());
+        using var provider = services.BuildServiceProvider();
+        var instance = new TestInjectable();
+
+        // Act
+        provider.InjectProperties(instance);
+
+        // Assert
+        instance.InjectedService.Should().NotBeNull();
+        instance.InjectedService.Should().BeOfType<TestService>();
+    }
+
+    [Test]
+    public void InjectProperties_SkipsNonMarkedProperties()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        services.AddSingleton<ITestService>(new TestService());
+        using var provider = services.BuildServiceProvider();
+        var instance = new TestInjectable();
+
+        // Act
+        provider.InjectProperties(instance);
+
+        // Assert
+        instance.NonInjectedService.Should().BeNull();
+    }
+
+    #region Test helpers
+
+    private interface ITestService { }
+
+    private class TestService : ITestService { }
+
+    private class TestInjectable
+    {
+        [Inject]
+        public ITestService? InjectedService { get; set; }
+
+        public ITestService? NonInjectedService { get; set; }
+    }
+
+    #endregion
+}
diff --git a/tests/Trax.Effect.Tests.Integration/UnitTests/Configuration/TraxEffectConfigurationBuilderTests.cs b/tests/Trax.Effect.Tests.Integration/UnitTests/Configuration/TraxEffectConfigurationBuilderTests.cs
new file mode 100644
index 0000000..f7cf99a
--- /dev/null
+++ b/tests/Trax.Effect.Tests.Integration/UnitTests/Configuration/TraxEffectConfigurationBuilderTests.cs
@@ -0,0 +1,71 @@
+using FluentAssertions;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Trax.Effect.Configuration.TraxEffectBuilder;
+
+namespace Trax.Effect.Tests.Integration.UnitTests.Configuration;
+
+[TestFixture]
+public class TraxEffectConfigurationBuilderTests
+{
+    [Test]
+    public void Constructor_DefaultValues_AreCorrect()
+    {
+        // Arrange & Act
+        var builder = new TraxEffectConfigurationBuilder(new ServiceCollection());
+
+        // Assert
+        builder.DataContextLoggingEffectEnabled.Should().BeFalse();
+        builder.SerializeStepData.Should().BeFalse();
+        builder.LogLevel.Should().Be(LogLevel.Debug);
+    }
+
+    [Test]
+    public void ServiceCollection_ExposedFromConstructor()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+
+        // Act
+        var builder = new TraxEffectConfigurationBuilder(services);
+
+        // Assert
+        builder.ServiceCollection.Should().BeSameAs(services);
+    }
+
+    [Test]
+    public void SetEffectLogLevel_UpdatesLogLevel()
+    {
+        // Arrange
+        var builder = new TraxEffectConfigurationBuilder(new ServiceCollection());
+
+        // Act
+        builder.LogLevel = LogLevel.Trace;
+
+        // Assert
+        builder.LogLevel.Should().Be(LogLevel.Trace);
+    }
+
+    [Test]
+    public void SerializeStepData_SetTrue_IsReflected()
+    {
+        // Arrange
+        var builder = new TraxEffectConfigurationBuilder(new ServiceCollection());
+
+        // Act
+        builder.SerializeStepData = true;
+
+        // Assert
+        builder.SerializeStepData.Should().BeTrue();
+    }
+
+    [Test]
+    public void TrainParameterJsonSerializerOptions_DefaultIsNotNull()
+    {
+        // Arrange & Act
+        var builder = new TraxEffectConfigurationBuilder(new ServiceCollection());
+
+        // Assert
+        builder.TrainParameterJsonSerializerOptions.Should().NotBeNull();
+    }
+}
diff --git a/tests/Trax.Effect.Tests.Integration/UnitTests/Extensions/ServiceExtensionsRegistrationTests.cs b/tests/Trax.Effect.Tests.Integration/UnitTests/Extensions/ServiceExtensionsRegistrationTests.cs
new file mode 100644
index 0000000..b30eb0b
--- /dev/null
+++ b/tests/Trax.Effect.Tests.Integration/UnitTests/Extensions/ServiceExtensionsRegistrationTests.cs
@@ -0,0 +1,127 @@
+using FluentAssertions;
+using LanguageExt;
+using Microsoft.Extensions.DependencyInjection;
+using Trax.Core.Route;
+using Trax.Core.Step;
+using Trax.Effect.Extensions;
+
+namespace Trax.Effect.Tests.Integration.UnitTests.Extensions;
+
+[TestFixture]
+public class ServiceExtensionsRegistrationTests
+{
+    [Test]
+    public void AddScopedTraxStep_Resolves_ViaInterface()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        services.AddScopedTraxStep<IFakeStep, FakeStep>();
+        using var provider = services.BuildServiceProvider();
+
+        // Act
+        var step = provider.GetService<IFakeStep>();
+
+        // Assert
+        step.Should().NotBeNull();
+        step.Should().BeOfType<FakeStep>();
+    }
+
+    [Test]
+    public void AddTransientTraxStep_Resolves_ViaInterface()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        services.AddTransientTraxStep<IFakeStep, FakeStep>();
+        using var provider = services.BuildServiceProvider();
+
+        // Act
+        var step = provider.GetService<IFakeStep>();
+
+        // Assert
+        step.Should().NotBeNull();
+        step.Should().BeOfType<FakeStep>();
+    }
+
+    [Test]
+    public void AddSingletonTraxStep_Resolves_ViaInterface()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        services.AddSingletonTraxStep<IFakeStep, FakeStep>();
+        using var provider = services.BuildServiceProvider();
+
+        // Act
+        var step = provider.GetService<IFakeStep>();
+
+        // Assert
+        step.Should().NotBeNull();
+        step.Should().BeOfType<FakeStep>();
+    }
+
+    [Test]
+    public void AddScopedTraxRoute_Resolves_ViaInterface()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        services.AddScopedTraxRoute<IFakeRoute, FakeRoute>();
+        using var provider = services.BuildServiceProvider();
+
+        // Act
+        var route = provider.GetService<IFakeRoute>();
+
+        // Assert
+        route.Should().NotBeNull();
+        route.Should().BeOfType<FakeRoute>();
+    }
+
+    [Test]
+    public void AddTransientTraxRoute_Resolves_ViaInterface()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        services.AddTransientTraxRoute<IFakeRoute, FakeRoute>();
+        using var provider = services.BuildServiceProvider();
+
+        // Act
+        var route = provider.GetService<IFakeRoute>();
+
+        // Assert
+        route.Should().NotBeNull();
+        route.Should().BeOfType<FakeRoute>();
+    }
+
+    [Test]
+    public void AddSingletonTraxRoute_Resolves_ViaInterface()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        services.AddSingletonTraxRoute<IFakeRoute, FakeRoute>();
+        using var provider = services.BuildServiceProvider();
+
+        // Act
+        var route = provider.GetService<IFakeRoute>();
+
+        // Assert
+        route.Should().NotBeNull();
+        route.Should().BeOfType<FakeRoute>();
+    }
+
+    #region Test helpers
+
+    public interface IFakeStep : IStep<string, int> { }
+
+    public class FakeStep : Step<string, int>, IFakeStep
+    {
+        public override Task<int> Run(string input) => Task.FromResult(input.Length);
+    }
+
+    public interface IFakeRoute : IRoute<string, int> { }
+
+    public class FakeRoute : IFakeRoute
+    {
+        public Task<int> Run(string input, CancellationToken cancellationToken = default) =>
+            Task.FromResult(input.Length);
+    }
+
+    #endregion
+}
diff --git a/tests/Trax.Effect.Tests.Integration/UnitTests/Utils/DisposableConverterTests.cs b/tests/Trax.Effect.Tests.Integration/UnitTests/Utils/DisposableConverterTests.cs
new file mode 100644
index 0000000..89210e7
--- /dev/null
+++ b/tests/Trax.Effect.Tests.Integration/UnitTests/Utils/DisposableConverterTests.cs
@@ -0,0 +1,50 @@
+using System.Text.Json;
+using FluentAssertions;
+using Trax.Effect.Utils;
+
+namespace Trax.Effect.Tests.Integration.UnitTests.Utils;
+
+[TestFixture]
+public class DisposableConverterTests
+{
+    [Test]
+    public void CanConvert_DisposableType_ReturnsTrue()
+    {
+        // Arrange
+        var converter = new DisposableConverter();
+
+        // Act
+        var result = converter.CanConvert(typeof(MemoryStream));
+
+        // Assert
+        result.Should().BeTrue();
+    }
+
+    [Test]
+    public void CanConvert_NonDisposableType_ReturnsFalse()
+    {
+        // Arrange
+        var converter = new DisposableConverter();
+
+        // Act
+        var result = converter.CanConvert(typeof(string));
+
+        // Assert
+        result.Should().BeFalse();
+    }
+
+    [Test]
+    public void Write_DisposableObject_WritesPlaceholder()
+    {
+        // Arrange
+        var options = new JsonSerializerOptions();
+        options.Converters.Add(new DisposableConverter());
+        using var stream = new MemoryStream();
+
+        // Act
+        var json = JsonSerializer.Serialize<object>(stream, options);
+
+        // Assert
+        json.Should().Contain("IDisposable");
+    }
+}
diff --git a/tests/Trax.Effect.Tests.Integration/UnitTests/Utils/ValueTupleConverterTests.cs b/tests/Trax.Effect.Tests.Integration/UnitTests/Utils/ValueTupleConverterTests.cs
new file mode 100644
index 0000000..07cdf29
--- /dev/null
+++ b/tests/Trax.Effect.Tests.Integration/UnitTests/Utils/ValueTupleConverterTests.cs
@@ -0,0 +1,83 @@
+using System.Text.Json;
+using FluentAssertions;
+using Trax.Effect.Utils;
+
+namespace Trax.Effect.Tests.Integration.UnitTests.Utils;
+
+[TestFixture]
+public class ValueTupleConverterTests
+{
+    private JsonSerializerOptions _options;
+
+    [SetUp]
+    public void SetUp()
+    {
+        _options = new JsonSerializerOptions();
+        _options.Converters.Add(new ValueTupleConverter());
+    }
+
+    [Test]
+    public void CanConvert_ValueTupleType_ReturnsTrue()
+    {
+        // Arrange
+        var converter = new ValueTupleConverter();
+
+        // Act
+        var result = converter.CanConvert(typeof((int, string)));
+
+        // Assert
+        result.Should().BeTrue();
+    }
+
+    [Test]
+    public void CanConvert_NonTupleType_ReturnsFalse()
+    {
+        // Arrange
+        var converter = new ValueTupleConverter();
+
+        // Act
+        var result = converter.CanConvert(typeof(int));
+
+        // Assert
+        result.Should().BeFalse();
+    }
+
+    [Test]
+    public void Serialize_Tuple2_ProducesJsonArray()
+    {
+        // Arrange
+        var tuple = (1, "hello");
+
+        // Act
+        var json = JsonSerializer.Serialize(tuple, _options);
+
+        // Assert
+        json.Should().Be("[1,\"hello\"]");
+    }
+
+    [Test]
+    public void Serialize_Tuple3_ProducesJsonArray()
+    {
+        // Arrange
+        var tuple = (1, 2, 3.0);
+
+        // Act
+        var json = JsonSerializer.Serialize(tuple, _options);
+
+        // Assert
+        json.Should().Be("[1,2,3]");
+    }
+
+    [Test]
+    public void CanConvert_NestedTupleType_ReturnsTrue()
+    {
+        // Arrange
+        var converter = new ValueTupleConverter();
+
+        // Act
+        var result = converter.CanConvert(typeof((int, int, int)));
+
+        // Assert
+        result.Should().BeTrue();
+    }
+}