diff --git a/.github/workflows/e2e.yml b/.github/workflows/e2e.yml
index 4dea1592..a9794050 100644
--- a/.github/workflows/e2e.yml
+++ b/.github/workflows/e2e.yml
@@ -34,4 +34,4 @@ jobs:
         cp spec/specification/assets/gherkin/evaluation.feature test/OpenFeature.E2ETests/Features/
 
     - name: Run Tests
-      run: dotnet test test/OpenFeature.E2ETests/ --configuration Release --logger GitHubActions
+      run: dotnet test test/OpenFeature.E2ETests/ --logger GitHubActions
diff --git a/src/OpenFeature/Providers/Memory/Flag.cs b/src/OpenFeature/Providers/Memory/Flag.cs
index af51b120..e1a88287 100644
--- a/src/OpenFeature/Providers/Memory/Flag.cs
+++ b/src/OpenFeature/Providers/Memory/Flag.cs
@@ -10,7 +10,7 @@ namespace OpenFeature.Providers.Memory
     /// <summary>
     /// Flag representation for the in-memory provider.
     /// </summary>
-    public class Flag
+    public interface Flag
     {
 
     }
@@ -22,7 +22,7 @@ public sealed class Flag<T> : Flag
     {
         private Dictionary<string, T> Variants;
         private string DefaultVariant;
-        private Func<EvaluationContext, string> ContextEvaluator;
+        private Func<EvaluationContext, string>? ContextEvaluator;
 
         /// <summary>
         /// Flag representation for the in-memory provider.
@@ -30,14 +30,14 @@ public sealed class Flag<T> : Flag
         /// <param name="variants">dictionary of variants and their corresponding values</param>
         /// <param name="defaultVariant">default variant (should match 1 key in variants dictionary)</param>
         /// <param name="contextEvaluator">optional context-sensitive evaluation function</param>
-        public Flag(Dictionary<string, T> variants, string defaultVariant, Func<EvaluationContext, string> contextEvaluator = null)
+        public Flag(Dictionary<string, T> variants, string defaultVariant, Func<EvaluationContext, string>? contextEvaluator = null)
         {
             this.Variants = variants;
             this.DefaultVariant = defaultVariant;
             this.ContextEvaluator = contextEvaluator;
         }
 
-        internal ResolutionDetails<T> Evaluate(string flagKey, T defaultValue, EvaluationContext evaluationContext)
+        internal ResolutionDetails<T> Evaluate(string flagKey, T _, EvaluationContext? evaluationContext)
         {
             T value;
             if (this.ContextEvaluator == null)
@@ -58,7 +58,7 @@ internal ResolutionDetails<T> Evaluate(string flagKey, T defaultValue, Evaluatio
             }
             else
             {
-                var variant = this.ContextEvaluator.Invoke(evaluationContext);
+                var variant = this.ContextEvaluator.Invoke(evaluationContext ?? EvaluationContext.Empty);
                 this.Variants.TryGetValue(variant, out value);
                 if (value == null)
                 {
diff --git a/src/OpenFeature/Providers/Memory/InMemoryProvider.cs b/src/OpenFeature/Providers/Memory/InMemoryProvider.cs
index 9aafd133..d7a9ffaf 100644
--- a/src/OpenFeature/Providers/Memory/InMemoryProvider.cs
+++ b/src/OpenFeature/Providers/Memory/InMemoryProvider.cs
@@ -32,7 +32,7 @@ public override Metadata GetMetadata()
         /// Construct a new InMemoryProvider.
         /// </summary>
         /// <param name="flags">dictionary of Flags</param>
-        public InMemoryProvider(IDictionary<string, Flag> flags = null)
+        public InMemoryProvider(IDictionary<string, Flag>? flags = null)
         {
             if (flags == null)
             {
@@ -67,7 +67,7 @@ public async ValueTask UpdateFlags(IDictionary<string, Flag> flags)
         public override Task<ResolutionDetails<bool>> ResolveBooleanValue(
             string flagKey,
             bool defaultValue,
-            EvaluationContext context = null)
+            EvaluationContext? context = null)
         {
             return Task.FromResult(Resolve(flagKey, defaultValue, context));
         }
@@ -76,7 +76,7 @@ public override Task<ResolutionDetails<bool>> ResolveBooleanValue(
         public override Task<ResolutionDetails<string>> ResolveStringValue(
             string flagKey,
             string defaultValue,
-            EvaluationContext context = null)
+            EvaluationContext? context = null)
         {
             return Task.FromResult(Resolve(flagKey, defaultValue, context));
         }
@@ -85,7 +85,7 @@ public override Task<ResolutionDetails<string>> ResolveStringValue(
         public override Task<ResolutionDetails<int>> ResolveIntegerValue(
             string flagKey,
             int defaultValue,
-            EvaluationContext context = null)
+            EvaluationContext? context = null)
         {
             return Task.FromResult(Resolve(flagKey, defaultValue, context));
         }
@@ -94,7 +94,7 @@ public override Task<ResolutionDetails<int>> ResolveIntegerValue(
         public override Task<ResolutionDetails<double>> ResolveDoubleValue(
             string flagKey,
             double defaultValue,
-            EvaluationContext context = null)
+            EvaluationContext? context = null)
         {
             return Task.FromResult(Resolve(flagKey, defaultValue, context));
         }
@@ -103,12 +103,12 @@ public override Task<ResolutionDetails<double>> ResolveDoubleValue(
         public override Task<ResolutionDetails<Value>> ResolveStructureValue(
             string flagKey,
             Value defaultValue,
-            EvaluationContext context = null)
+            EvaluationContext? context = null)
         {
             return Task.FromResult(Resolve(flagKey, defaultValue, context));
         }
 
-        private ResolutionDetails<T> Resolve<T>(string flagKey, T defaultValue, EvaluationContext context)
+        private ResolutionDetails<T> Resolve<T>(string flagKey, T defaultValue, EvaluationContext? context)
         {
             if (!this._flags.TryGetValue(flagKey, out var flag))
             {
@@ -118,7 +118,7 @@ private ResolutionDetails<T> Resolve<T>(string flagKey, T defaultValue, Evaluati
             {
                 if (typeof(Flag<T>).Equals(flag.GetType()))
                 {
-                    return (flag as Flag<T>).Evaluate(flagKey, defaultValue, context);
+                    return ((Flag<T>)flag).Evaluate(flagKey, defaultValue, context);
                 }
                 else
                 {
diff --git a/test/OpenFeature.Tests/InMemoryProviderTests.cs b/test/OpenFeature.Tests/InMemoryProviderTests.cs
index 61587cf4..799fd9db 100644
--- a/test/OpenFeature.Tests/InMemoryProviderTests.cs
+++ b/test/OpenFeature.Tests/InMemoryProviderTests.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Threading;
 using OpenFeature.Constant;
 using OpenFeature.Error;
 using OpenFeature.Model;
@@ -9,16 +10,133 @@
 
 namespace OpenFeature.Tests
 {
-    // most of the in-memory tests are handled in the e2e suite
     public class InMemoryProviderTests
     {
+        private FeatureProvider commonProvider;
+
+        public InMemoryProviderTests()
+        {
+            var provider = new InMemoryProvider(new Dictionary<string, Flag>(){
+                {
+                    "boolean-flag", new Flag<bool>(
+                        variants: new Dictionary<string, bool>(){
+                            { "on", true },
+                            { "off", false }
+                        },
+                        defaultVariant: "on"
+                    )
+                },
+                {
+                    "string-flag", new Flag<string>(
+                        variants: new Dictionary<string, string>(){
+                            { "greeting", "hi" },
+                            { "parting", "bye" }
+                        },
+                        defaultVariant: "greeting"
+                    )
+                },
+                {
+                    "integer-flag", new Flag<int>(
+                        variants: new Dictionary<string, int>(){
+                            { "one", 1 },
+                            { "ten", 10 }
+                        },
+                        defaultVariant: "ten"
+                    )
+                },
+                {
+                    "float-flag", new Flag<double>(
+                        variants: new Dictionary<string, double>(){
+                            { "tenth", 0.1 },
+                            { "half", 0.5 }
+                        },
+                        defaultVariant: "half"
+                    )
+                },
+                {
+                    "object-flag", new Flag<Value>(
+                        variants: new Dictionary<string, Value>(){
+                            { "empty", new Value() },
+                            { "template", new Value(Structure.Builder()
+                                    .Set("showImages", true)
+                                    .Set("title", "Check out these pics!")
+                                    .Set("imagesPerPage", 100).Build()
+                                )
+                            }
+                        },
+                        defaultVariant: "template"
+                    )
+                }
+            });
+
+            this.commonProvider = provider;
+        }
+
+        [Fact]
+        public async void GetBoolean_ShouldEvaluate()
+        {
+            ResolutionDetails<bool> details = await this.commonProvider.ResolveBooleanValue("boolean-flag", false, EvaluationContext.Empty).ConfigureAwait(false);
+            Assert.True(details.Value);
+            Assert.Equal(Reason.Static, details.Reason);
+            Assert.Equal("on", details.Variant);
+        }
+
+        [Fact]
+        public async void GetString_ShouldEvaluate()
+        {
+            ResolutionDetails<string> details = await this.commonProvider.ResolveStringValue("string-flag", "nope", EvaluationContext.Empty).ConfigureAwait(false);
+            Assert.Equal("hi", details.Value);
+            Assert.Equal(Reason.Static, details.Reason);
+            Assert.Equal("greeting", details.Variant);
+        }
+
+        [Fact]
+        public async void GetInt_ShouldEvaluate()
+        {
+            ResolutionDetails<int> details = await this.commonProvider.ResolveIntegerValue("integer-flag", 13, EvaluationContext.Empty).ConfigureAwait(false);
+            Assert.Equal(10, details.Value);
+            Assert.Equal(Reason.Static, details.Reason);
+            Assert.Equal("ten", details.Variant);
+        }
+
+        [Fact]
+        public async void GetDouble_ShouldEvaluate()
+        {
+            ResolutionDetails<double> details = await this.commonProvider.ResolveDoubleValue("float-flag", 13, EvaluationContext.Empty).ConfigureAwait(false);
+            Assert.Equal(0.5, details.Value);
+            Assert.Equal(Reason.Static, details.Reason);
+            Assert.Equal("half", details.Variant);
+        }
+
+        [Fact]
+        public async void GetStruct_ShouldEvaluate()
+        {
+            ResolutionDetails<Value> details = await this.commonProvider.ResolveStructureValue("object-flag", new Value(), EvaluationContext.Empty).ConfigureAwait(false);
+            Assert.Equal(true, details.Value.AsStructure["showImages"].AsBoolean);
+            Assert.Equal("Check out these pics!", details.Value.AsStructure["title"].AsString);
+            Assert.Equal(100, details.Value.AsStructure["imagesPerPage"].AsInteger);
+            Assert.Equal(Reason.Static, details.Reason);
+            Assert.Equal("template", details.Variant);
+        }
+
+        [Fact]
+        public async void MissingFlag_ShouldThrow()
+        {
+            await Assert.ThrowsAsync<FlagNotFoundException>(() => commonProvider.ResolveBooleanValue("missing-flag", false, EvaluationContext.Empty)).ConfigureAwait(false);
+        }
+
+        [Fact]
+        public async void MismatchedFlag_ShouldThrow()
+        {
+            await Assert.ThrowsAsync<TypeMismatchException>(() => commonProvider.ResolveStringValue("boolean-flag", "nope", EvaluationContext.Empty)).ConfigureAwait(false);
+        }
+
         [Fact]
         public async void PutConfiguration_shouldUpdateConfigAndRunHandlers()
         {
-            var handlerRuns = 0;
             var provider = new InMemoryProvider(new Dictionary<string, Flag>(){
             {
-                "boolean-flag", new Flag<bool>(
+                "old-flag", new Flag<bool>(
                     variants: new Dictionary<string, bool>(){
                         { "on", true },
                         { "off", false }
@@ -27,19 +145,13 @@ public async void PutConfiguration_shouldUpdateConfigAndRunHandlers()
                 )
             }});
 
-            // setup client and handler and run initial eval
-            await Api.Instance.SetProviderAsync("mem-test", provider).ConfigureAwait(false);
-            var client = Api.Instance.GetClient("mem-test");
-            client.AddHandler(ProviderEventTypes.ProviderConfigurationChanged, (details) =>
-            {
-                handlerRuns++;
-            });
-            Assert.True(await client.GetBooleanValue("boolean-flag", false).ConfigureAwait(false));
+            ResolutionDetails<bool> details = await provider.ResolveBooleanValue("old-flag", false, EvaluationContext.Empty).ConfigureAwait(false);
+            Assert.True(details.Value);
 
             // update flags
             await provider.UpdateFlags(new Dictionary<string, Flag>(){
             {
-                "string-flag", new Flag<string>(
+                "new-flag", new Flag<string>(
                     variants: new Dictionary<string, string>(){
                         { "greeting", "hi" },
                         { "parting", "bye" }
@@ -48,10 +160,15 @@ await provider.UpdateFlags(new Dictionary<string, Flag>(){
                 )
             }}).ConfigureAwait(false);
 
+            var res = await provider.GetEventChannel().Reader.ReadAsync().ConfigureAwait(false) as ProviderEventPayload;
+            Assert.Equal(ProviderEventTypes.ProviderConfigurationChanged, res.Type);
+
+            await Assert.ThrowsAsync<FlagNotFoundException>(() => provider.ResolveBooleanValue("old-flag", false, EvaluationContext.Empty)).ConfigureAwait(false);
+
             // new flag should be present, old gone (defaults), handler run.
-            Assert.Equal("hi", await client.GetStringValue("string-flag", "nope").ConfigureAwait(false));
-            Assert.False(await client.GetBooleanValue("boolean-flag", false).ConfigureAwait(false));
-            Assert.Equal(1, handlerRuns);
+            ResolutionDetails<string> detailsAfter = await provider.ResolveStringValue("new-flag", "nope", EvaluationContext.Empty).ConfigureAwait(false);
+            Assert.True(details.Value);
+            Assert.Equal("hi", detailsAfter.Value);
         }
     }
 }