diff --git a/src/PatternKit.Generators/Messaging/CompetingConsumerGroupGenerator.cs b/src/PatternKit.Generators/Messaging/CompetingConsumerGroupGenerator.cs
index 03bb8793..439ed275 100644
--- a/src/PatternKit.Generators/Messaging/CompetingConsumerGroupGenerator.cs
+++ b/src/PatternKit.Generators/Messaging/CompetingConsumerGroupGenerator.cs
@@ -94,6 +94,50 @@ private static string GenerateSource(
             sb.AppendLine();
         }
 
+        var containingTypes = GetContainingTypes(type);
+        var indentLevel = 0;
+        foreach (var containingType in containingTypes)
+        {
+            AppendTypeDeclaration(sb, containingType, indentLevel);
+            sb.AppendLine();
+            sb.AppendLine(new string(' ', indentLevel * 4) + "{");
+            indentLevel++;
+        }
+
+        AppendTypeDeclaration(sb, type, indentLevel);
+        var indent = new string(' ', indentLevel * 4);
+        sb.AppendLine();
+        sb.AppendLine(indent + "{");
+        var memberIndent = indent + "    ";
+        var bodyIndent = memberIndent + "    ";
+        sb.Append(memberIndent).Append("public static global::PatternKit.Messaging.CompetingConsumers.CompetingConsumerGroup<").Append(messageTypeName).Append(", ").Append(resultTypeName).Append(">.Builder ").Append(factoryMethodName).AppendLine("()");
+        sb.AppendLine(memberIndent + "{");
+        sb.Append(bodyIndent).Append("return global::PatternKit.Messaging.CompetingConsumers.CompetingConsumerGroup<").Append(messageTypeName).Append(", ").Append(resultTypeName).Append(">.Create(\"").Append(Escape(groupName)).AppendLine("\")");
+        sb.Append(bodyIndent).Append("    .WithMaxConcurrentDeliveries(").Append(maxConcurrentDeliveries).AppendLine(");");
+        sb.AppendLine(memberIndent + "}");
+        sb.AppendLine(indent + "}");
+        for (var i = containingTypes.Length - 1; i >= 0; i--)
+        {
+            sb.AppendLine(new string(' ', i * 4) + "}");
+        }
+
+        return sb.ToString();
+    }
+
+    private static INamedTypeSymbol[] GetContainingTypes(INamedTypeSymbol type)
+    {
+        var containingTypes = new Stack<INamedTypeSymbol>();
+        for (var current = type.ContainingType; current is not null; current = current.ContainingType)
+        {
+            containingTypes.Push(current);
+        }
+
+        return containingTypes.ToArray();
+    }
+
+    private static void AppendTypeDeclaration(StringBuilder sb, INamedTypeSymbol type, int indentLevel)
+    {
+        sb.Append(new string(' ', indentLevel * 4));
         sb.Append(GetAccessibility(type.DeclaredAccessibility)).Append(' ');
         if (type.IsStatic)
             sb.Append("static ");
@@ -101,15 +145,7 @@ private static string GenerateSource(
             sb.Append("abstract ");
         else if (type.IsSealed && type.TypeKind == TypeKind.Class)
             sb.Append("sealed ");
-        sb.Append("partial ").Append(type.TypeKind == TypeKind.Struct ? "struct" : "class").Append(' ').Append(type.Name).AppendLine();
-        sb.AppendLine("{");
-        sb.Append("    public static global::PatternKit.Messaging.CompetingConsumers.CompetingConsumerGroup<").Append(messageTypeName).Append(", ").Append(resultTypeName).Append(">.Builder ").Append(factoryMethodName).AppendLine("()");
-        sb.AppendLine("    {");
-        sb.Append("        return global::PatternKit.Messaging.CompetingConsumers.CompetingConsumerGroup<").Append(messageTypeName).Append(", ").Append(resultTypeName).Append(">.Create(\"").Append(Escape(groupName)).AppendLine("\")");
-        sb.Append("            .WithMaxConcurrentDeliveries(").Append(maxConcurrentDeliveries).AppendLine(");");
-        sb.AppendLine("    }");
-        sb.AppendLine("}");
-        return sb.ToString();
+        sb.Append("partial ").Append(type.TypeKind == TypeKind.Struct ? "struct" : "class").Append(' ').Append(type.Name);
     }
 
     private static string Escape(string value) => value.Replace("\\", "\\\\").Replace("\"", "\\\"");
diff --git a/test/PatternKit.Generators.Tests/CompetingConsumerGroupGeneratorTests.cs b/test/PatternKit.Generators.Tests/CompetingConsumerGroupGeneratorTests.cs
index ff644b29..30481870 100644
--- a/test/PatternKit.Generators.Tests/CompetingConsumerGroupGeneratorTests.cs
+++ b/test/PatternKit.Generators.Tests/CompetingConsumerGroupGeneratorTests.cs
@@ -15,9 +15,12 @@ public sealed partial class CompetingConsumerGroupGeneratorTests(ITestOutputHelp
     public Task Generates_Competing_Consumer_Group_Builder_Factory()
         => Given("a competing consumer group declaration", () => Compile("""
             using PatternKit.Generators.Messaging;
+
             namespace Demo;
+
             public sealed record FulfillmentWork(string OrderId);
             public sealed record FulfillmentResult(string OrderId, string Consumer);
+
             [GenerateCompetingConsumerGroup(typeof(FulfillmentWork), typeof(FulfillmentResult), FactoryMethodName = "Build", GroupName = "fulfillment-consumers", MaxConcurrentDeliveries = 4)]
             public static partial class FulfillmentConsumers;
             """))
@@ -55,6 +58,103 @@ public static partial class ConsumerHost;
         })
         .AssertPassed();
 
+    [Scenario("Generates competing consumer group defaults and type shapes")]
+    [Fact]
+    public Task Generates_Competing_Consumer_Group_Defaults_And_Type_Shapes()
+        => Given("competing consumer declarations using default names and different host shapes", () => Compile("""
+            using PatternKit.Generators.Messaging;
+
+            namespace Demo;
+
+            public sealed record FulfillmentWork(string OrderId);
+            public sealed record FulfillmentResult(string OrderId, string Consumer);
+
+            [GenerateCompetingConsumerGroup(typeof(FulfillmentWork), typeof(FulfillmentResult))]
+            internal abstract partial class AbstractConsumers;
+
+            [GenerateCompetingConsumerGroup(typeof(FulfillmentWork), typeof(FulfillmentResult), GroupName = "tenant\\\"consumers", MaxConcurrentDeliveries = 3)]
+            public sealed partial class SealedConsumers;
+
+            [GenerateCompetingConsumerGroup(typeof(FulfillmentWork), typeof(FulfillmentResult))]
+            internal partial struct StructConsumers;
+            """))
+        .Then("generated sources preserve host shape and configured names", result =>
+        {
+            ScenarioExpect.Empty(result.Diagnostics);
+            ScenarioExpect.Equal(3, result.GeneratedSources.Count);
+
+            var combined = string.Join("\n", result.GeneratedSources);
+            ScenarioExpect.Contains("internal abstract partial class AbstractConsumers", combined);
+            ScenarioExpect.Contains("Create()", combined);
+            ScenarioExpect.Contains("Create(\"competing-consumers\")", combined);
+            ScenarioExpect.Contains(".WithMaxConcurrentDeliveries(1)", combined);
+            ScenarioExpect.Contains("public sealed partial class SealedConsumers", combined);
+            ScenarioExpect.Contains("Create(\"tenant\\\\\\\"consumers\")", combined);
+            ScenarioExpect.Contains(".WithMaxConcurrentDeliveries(3)", combined);
+            ScenarioExpect.Contains("internal partial struct StructConsumers", combined);
+            ScenarioExpect.True(result.EmitSuccess, string.Join(Environment.NewLine, result.EmitDiagnostics));
+        })
+        .AssertPassed();
+
+    [Scenario("Generates nested competing consumer group host wrappers")]
+    [Fact]
+    public Task Generates_Nested_Competing_Consumer_Group_Host_Wrappers()
+        => Given("nested competing consumer declarations with non-public accessibility", () => Compile("""
+            using PatternKit.Generators.Messaging;
+
+            namespace Demo;
+
+            public sealed record FulfillmentWork(string OrderId);
+            public sealed record FulfillmentResult(string OrderId, string Consumer);
+
+            public partial class ConsumerContainer
+            {
+                private partial class PrivateHost
+                {
+                    [GenerateCompetingConsumerGroup(typeof(FulfillmentWork), typeof(FulfillmentResult))]
+                    protected partial class ProtectedConsumers;
+
+                    [GenerateCompetingConsumerGroup(typeof(FulfillmentWork), typeof(FulfillmentResult))]
+                    private protected partial class PrivateProtectedConsumers;
+
+                    [GenerateCompetingConsumerGroup(typeof(FulfillmentWork), typeof(FulfillmentResult))]
+                    protected internal partial class ProtectedInternalConsumers;
+                }
+            }
+            """))
+        .Then("generated sources preserve containing partial type wrappers", result =>
+        {
+            ScenarioExpect.Empty(result.Diagnostics);
+            ScenarioExpect.Equal(3, result.GeneratedSources.Count);
+
+            var combined = string.Join("\n", result.GeneratedSources);
+            ScenarioExpect.Contains("public partial class ConsumerContainer", combined);
+            ScenarioExpect.Contains("private partial class PrivateHost", combined);
+            ScenarioExpect.Contains("protected partial class ProtectedConsumers", combined);
+            ScenarioExpect.Contains("private protected partial class PrivateProtectedConsumers", combined);
+            ScenarioExpect.Contains("protected internal partial class ProtectedInternalConsumers", combined);
+            ScenarioExpect.True(result.EmitSuccess, string.Join(Environment.NewLine, result.EmitDiagnostics));
+        })
+        .AssertPassed();
+
+    [Scenario("Skips malformed competing consumer group type arguments")]
+    [Theory]
+    [InlineData("null!", "typeof(FulfillmentResult)")]
+    [InlineData("typeof(FulfillmentWork)", "null!")]
+    public Task Skips_Malformed_Competing_Consumer_Group_Type_Arguments(string messageType, string resultType)
+        => Given("a competing consumer declaration with a null type argument", () => Compile($$"""
+            using PatternKit.Generators.Messaging;
+
+            public sealed record FulfillmentWork(string OrderId);
+            public sealed record FulfillmentResult(string OrderId, string Consumer);
+
+            [GenerateCompetingConsumerGroup({{messageType}}, {{resultType}})]
+            public static partial class FulfillmentConsumers;
+            """))
+        .Then("no source is generated", result =>
+            ScenarioExpect.Empty(result.GeneratedSources))
+        .AssertPassed();
+
     private static GeneratorResult Compile(string source)
     {
         var compilation = RoslynTestHelpers.CreateCompilation(