Overhaul asset creation handlers.

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/AnimBlueprint_Create.h

@@ -4,6 +4,7 @@
 #include "MCPHandler.h"
 #include "MCPAssetFinder.h"
 #include "MCPUtils.h"
+#include "MCPPackageMaker.h"
 #include "Animation/AnimBlueprint.h"
 #include "Animation/AnimBlueprintGeneratedClass.h"
 #include "Animation/AnimInstance.h"
@@ -22,11 +23,8 @@ class UMCP_AnimBlueprint_Create : public UObject, public IMCPHandler
 	GENERATED_BODY()
 
 public:
-	UPROPERTY(meta=(Description="Name for the new Animation Blueprint asset"))
+	UPROPERTY(meta=(Description="Full asset path for the new Animation Blueprint (e.g. '/Game/AnimBP/ABP_Character')"))
-	FString Name;
+	FString AssetPath;
-
-	UPROPERTY(meta=(Description="Package path where the asset will be created (must start with /Game)"))
-	FString PackagePath;
 
 	UPROPERTY(meta=(Description="Name or path of the skeleton asset to use"))
 	FString Skeleton;
@@ -43,19 +41,8 @@ public:
 	{
 		MCPErrorCallback CB(Result);
 
-		if (Name.IsEmpty() || PackagePath.IsEmpty() || Skeleton.IsEmpty())
+		MCPPackageMaker Maker(AssetPath, CB);
-		{
+		if (!Maker.Ok()) return;
-			return CB.SetError(TEXT("Missing required fields: name, packagePath, skeleton"));
-		}
-
-		if (!PackagePath.StartsWith(TEXT("/Game")))
-		{
-			return CB.SetError(TEXT("packagePath must start with '/Game'"));
-		}
-
-		// Check if asset already exists
-		MCPAssets<UBlueprint> ExistCheck;
-		if (!ExistCheck.Exact(Name).Errors(CB).EAny().Info()) return;
 
 		// Resolve skeleton
 		MCPAssets<USkeleton> SkeletonAssets;
@@ -82,20 +69,14 @@ public:
 			ParentClassObj = Found;
 		}
 
-		// Create the package
+		// Create the package and Animation Blueprint
-		FString FullPackagePath = PackagePath / Name;
+		if (!Maker.Make()) return;
-		UPackage* Package = CreatePackage(*FullPackagePath);
-		if (!Package)
-		{
-			return CB.SetError(FString::Printf(TEXT("Failed to create package at '%s'"), *FullPackagePath));
-		}
 
-		// Create the Animation Blueprint
 		UAnimBlueprint* NewAnimBP = CastChecked<UAnimBlueprint>(
 			FKismetEditorUtilities::CreateBlueprint(
 				ParentClassObj,
-				Package,
+				Maker.Package(),
-				FName(*Name),
+				FName(*Maker.Name()),
 				BPTYPE_Normal,
 				UAnimBlueprint::StaticClass(),
 				UAnimBlueprintGeneratedClass::StaticClass()
@@ -113,7 +94,7 @@ public:
 		FKismetEditorUtilities::CompileBlueprint(NewAnimBP);
 		bool bSaved = MCPUtils::SaveBlueprintPackage(NewAnimBP);
 
-		Result.Appendf(TEXT("Created: %s\n"), *FullPackagePath);
+		Result.Appendf(TEXT("Created: %s\n"), *AssetPath);
 		Result.Appendf(TEXT("ParentClass: %s\n"), *MCPUtils::FormatName(ParentClassObj));
 		Result.Appendf(TEXT("Saved: %s\n"), bSaved ? TEXT("true") : TEXT("false"));
 

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/BlendSpace_Create.h

@@ -4,6 +4,7 @@
 #include "MCPHandler.h"
 #include "MCPAssetFinder.h"
 #include "MCPUtils.h"
+#include "MCPPackageMaker.h"
 #include "Animation/Skeleton.h"
 #include "Animation/BlendSpace.h"
 #include "BlendSpace_Create.generated.h"
@@ -19,11 +20,8 @@ class UMCP_BlendSpace_Create : public UObject, public IMCPHandler
 	GENERATED_BODY()
 
 public:
-	UPROPERTY(meta=(Description="Name for the new Blend Space asset"))
+	UPROPERTY(meta=(Description="Full asset path for the new Blend Space (e.g. '/Game/BlendSpaces/BS_Locomotion')"))
-	FString Name;
+	FString AssetPath;
-
-	UPROPERTY(meta=(Description="Package path where the asset will be created (must start with /Game)"))
-	FString PackagePath;
 
 	UPROPERTY(meta=(Description="Name or path of the skeleton asset to use"))
 	FString Skeleton;
@@ -35,32 +33,19 @@ public:
 
 	virtual void Handle(FStringBuilderBase& Result) override
 	{
-		if (!PackagePath.StartsWith(TEXT("/Game")))
+		MCPErrorCallback CB(Result);
-		{
-			Result.Append(TEXT("ERROR: PackagePath must start with '/Game'\n"));
-			return;
-		}
 
-		// Check if an asset with this name already exists.
+		MCPPackageMaker Maker(AssetPath, CB);
-		MCPAssets<UBlendSpace> ExistCheck;
+		if (!Maker.Ok()) return;
-		if (!ExistCheck.Exact(Name).Errors(Result).EAny().Info()) return;
 
 		// Resolve skeleton.
 		MCPAssets<USkeleton> SkeletonAssets;
-		if (!SkeletonAssets.Exact(Skeleton).Errors(Result).ENone().ETwo().Load()) return;
+		if (!SkeletonAssets.Exact(Skeleton).Errors(CB).ENone().ETwo().Load()) return;
 		USkeleton* SkeletonObj = SkeletonAssets.Object();
 
-		// Create the package.
+		// Create the package and Blend Space.
-		FString FullPackagePath = PackagePath / Name;
+		if (!Maker.Make()) return;
-		UPackage* Package = CreatePackage(*FullPackagePath);
+		UBlendSpace* NewBS = NewObject<UBlendSpace>(Maker.Package(), FName(*Maker.Name()), RF_Public | RF_Standalone);
-		if (!Package)
-		{
-			Result.Appendf(TEXT("ERROR: Failed to create package at '%s'\n"), *FullPackagePath);
-			return;
-		}
-
-		// Create the Blend Space.
-		UBlendSpace* NewBS = NewObject<UBlendSpace>(Package, FName(*Name), RF_Public | RF_Standalone);
 		if (!NewBS)
 		{
 			Result.Append(TEXT("ERROR: Failed to create Blend Space object\n"));

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/Blueprint_Create.h

@@ -2,8 +2,8 @@
 
 #include "CoreMinimal.h"
 #include "MCPHandler.h"
-#include "MCPAssetFinder.h"
 #include "MCPUtils.h"
+#include "MCPPackageMaker.h"
 #include "Engine/Blueprint.h"
 #include "Kismet2/KismetEditorUtilities.h"
 #include "Blueprint_Create.generated.h"
@@ -19,11 +19,8 @@ class UMCP_Blueprint_Create : public UObject, public IMCPHandler
 	GENERATED_BODY()
 
 public:
-	UPROPERTY(meta=(Description="New Blueprint asset name"))
+	UPROPERTY(meta=(Description="Full asset path for the new Blueprint (e.g. '/Game/Blueprints/BP_MyActor')"))
-	FString Blueprint;
+	FString AssetPath;
-
-	UPROPERTY(meta=(Description="Package path where the asset will be created (must start with /Game)"))
-	FString PackagePath;
 
 	UPROPERTY(meta=(Description="Parent class name (C++ class name or Blueprint name)"))
 	FString ParentClass;
@@ -40,15 +37,8 @@ public:
 	{
 		MCPErrorCallback Error(Result);
 
-		// Validate packagePath starts with /Game
+		MCPPackageMaker Maker(AssetPath, Error);
-		if (!PackagePath.StartsWith(TEXT("/Game")))
+		if (!Maker.Ok()) return;
-		{
-			return Error.SetError(TEXT("PackagePath must start with '/Game'"));
-		}
-
-		// Check if asset already exists
-		MCPAssets<UBlueprint> ExistCheck;
-		if (!ExistCheck.Exact(Blueprint).Errors(Error).EAny().Info()) return;
 
 		// Resolve parent class — try C++ class first, then Blueprint asset
 		UClass* ParentClassObj = MCPUtils::FindClassByName(ParentClass);
@@ -81,19 +71,13 @@ public:
 			ParentClassObj = UInterface::StaticClass();
 		}
 
-		// Create the package
+		// Create the package and Blueprint
-		FString FullPackagePath = PackagePath / Blueprint;
+		if (!Maker.Make()) return;
-		UPackage* Package = CreatePackage(*FullPackagePath);
-		if (!Package)
-		{
-			return Error.SetError(FString::Printf(TEXT("Failed to create package at '%s'"), *FullPackagePath));
-		}
 
-		// Create the Blueprint
 		UBlueprint* NewBP = FKismetEditorUtilities::CreateBlueprint(
 			ParentClassObj,
-			Package,
+			Maker.Package(),
-			FName(*Blueprint),
+			FName(*Maker.Name()),
 			BlueprintTypeEnum,
 			UBlueprint::StaticClass(),
 			UBlueprintGeneratedClass::StaticClass()

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/Enum_Create.h

@@ -6,9 +6,8 @@
 #include "MCPUtils.h"
 #include "Engine/UserDefinedEnum.h"
 #include "Kismet2/EnumEditorUtils.h"
-#include "AssetToolsModule.h"
-#include "IAssetTools.h"
 #include "Factories/EnumFactory.h"
+#include "MCPPackageMaker.h"
 #include "Enum_Create.generated.h"
 
 
@@ -35,12 +34,10 @@ public:
 
 	virtual void Handle(FStringBuilderBase& Result) override
 	{
-		FString PackagePath, AssetName;
+		MCPErrorCallback Error(Result);
-		if (!MCPUtils::SplitAssetPath(AssetPath, PackagePath, AssetName))
+
-		{
+		MCPPackageMaker Maker(AssetPath, Error);
-			Result.Append(TEXT("ERROR: AssetPath must be a full path (e.g. '/Game/DataTypes/E_MyEnum')\n"));
+		if (!Maker.Ok()) return;
-			return;
-		}
 
 		TArray<FString> EnumValues;
 		for (const TSharedPtr<FJsonValue>& Val : Values.Array)
@@ -50,25 +47,12 @@ public:
 		}
 		if (EnumValues.Num() == 0)
 		{
-			Result.Append(TEXT("ERROR: Values must be a non-empty array of strings\n"));
+			return Error.SetError(TEXT("Values must be a non-empty array of strings"));
-			return;
 		}
 
-		// Check that no enum with this name already exists.
-		MCPAssets<UUserDefinedEnum> ExistCheck;
-		if (!ExistCheck.Exact(AssetName).Errors(Result).EAny().Info()) return;
-
 		// Create the enum using AssetTools.
-		IAssetTools& AssetTools = FModuleManager::LoadModuleChecked<FAssetToolsModule>("AssetTools").Get();
+		UUserDefinedEnum* NewEnum = Maker.CreateAsset<UUserDefinedEnum, UEnumFactory>();
-		UEnumFactory* Factory = NewObject<UEnumFactory>();
+		if (!NewEnum) return;
-		UObject* NewAsset = AssetTools.CreateAsset(AssetName, PackagePath, UUserDefinedEnum::StaticClass(), Factory);
-
-		UUserDefinedEnum* NewEnum = Cast<UUserDefinedEnum>(NewAsset);
-		if (!NewEnum)
-		{
-			Result.Append(TEXT("ERROR: Failed to create UserDefinedEnum asset\n"));
-			return;
-		}
 
 		// Add enum values — UUserDefinedEnum starts with a MAX value.
 		// We need to add entries before MAX.

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/MaterialFunction_Create.h

@@ -6,8 +6,7 @@
 #include "MCPUtils.h"
 #include "Materials/MaterialFunction.h"
 #include "Factories/MaterialFunctionFactoryNew.h"
-#include "AssetToolsModule.h"
+#include "MCPPackageMaker.h"
-#include "IAssetTools.h"
 #include "MaterialFunction_Create.generated.h"
 
 
@@ -21,11 +20,8 @@ class UMCP_MaterialFunction_Create : public UObject, public IMCPHandler
 	GENERATED_BODY()
 
 public:
-	UPROPERTY(meta=(Description="Name for the new material function asset"))
+	UPROPERTY(meta=(Description="Full asset path for the new material function (e.g. '/Game/Materials/MF_MyFunc')"))
-	FString Name;
+	FString AssetPath;
-
-	UPROPERTY(meta=(Description="Package path where the asset will be created (must start with /Game)"))
-	FString PackagePath;
 
 	UPROPERTY(meta=(Optional, Description="Description for the material function"))
 	FString Description;
@@ -37,27 +33,14 @@ public:
 
 	virtual void Handle(FStringBuilderBase& Result) override
 	{
-		if (!PackagePath.StartsWith(TEXT("/Game")))
+		MCPErrorCallback Error(Result);
-		{
-			Result.Append(TEXT("ERROR: PackagePath must start with '/Game'\n"));
-			return;
-		}
 
-		// Check if asset already exists.
+		MCPPackageMaker Maker(AssetPath, Error);
-		MCPAssets<UMaterialFunction> ExistCheck;
+		if (!Maker.Ok()) return;
-		if (!ExistCheck.Exact(Name).Errors(Result).EAny().Info()) return;
 
 		// Create via IAssetTools + factory.
-		IAssetTools& AssetTools = FModuleManager::LoadModuleChecked<FAssetToolsModule>("AssetTools").Get();
+		UMaterialFunction* MF = Maker.CreateAsset<UMaterialFunction, UMaterialFunctionFactoryNew>();
-		UMaterialFunctionFactoryNew* Factory = NewObject<UMaterialFunctionFactoryNew>();
+		if (!MF) return;
-		UObject* NewAsset = AssetTools.CreateAsset(Name, PackagePath, UMaterialFunction::StaticClass(), Factory);
-
-		UMaterialFunction* MF = Cast<UMaterialFunction>(NewAsset);
-		if (!MF)
-		{
-			Result.Appendf(TEXT("ERROR: Failed to create Material Function '%s' in '%s'\n"), *Name, *PackagePath);
-			return;
-		}
 
 		// Set optional description.
 		if (!Description.IsEmpty())

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/MaterialInstance_Create.h

@@ -8,8 +8,7 @@
 #include "Materials/MaterialInterface.h"
 #include "Materials/MaterialInstanceConstant.h"
 #include "Factories/MaterialInstanceConstantFactoryNew.h"
-#include "AssetToolsModule.h"
+#include "MCPPackageMaker.h"
-#include "IAssetTools.h"
 #include "MaterialInstance_Create.generated.h"
 
 
@@ -23,11 +22,8 @@ class UMCP_MaterialInstance_Create : public UObject, public IMCPHandler
 	GENERATED_BODY()
 
 public:
-	UPROPERTY(meta=(Description="Name for the new Material Instance asset"))
+	UPROPERTY(meta=(Description="Full asset path for the new Material Instance (e.g. '/Game/Materials/MI_GoldShiny')"))
-	FString Name;
+	FString AssetPath;
-
-	UPROPERTY(meta=(Description="Package path where the asset will be created (must start with /Game)"))
-	FString PackagePath;
 
 	UPROPERTY(meta=(Description="Parent material name or path (Material or Material Instance)"))
 	FString ParentMaterial;
@@ -39,15 +35,10 @@ public:
 
 	virtual void Handle(FStringBuilderBase& Result) override
 	{
-		if (!PackagePath.StartsWith(TEXT("/Game")))
+		MCPErrorCallback Error(Result);
-		{
-			Result.Append(TEXT("ERROR: PackagePath must start with '/Game'\n"));
-			return;
-		}
 
-		// Check if asset already exists.
+		MCPPackageMaker Maker(AssetPath, Error);
-		MCPAssets<UMaterialInstanceConstant> ExistCheck;
+		if (!Maker.Ok()) return;
-		if (!ExistCheck.Exact(Name).Errors(Result).EAny().Info()) return;
 
 		// Load parent material -- try as Material first, then as Material Instance.
 		UMaterialInterface* ParentMaterialObj = nullptr;
@@ -79,16 +70,8 @@ public:
 		}
 
 		// Create via factory + AssetTools.
-		IAssetTools& AssetTools = FModuleManager::LoadModuleChecked<FAssetToolsModule>("AssetTools").Get();
+		UMaterialInstanceConstant* MI = Maker.CreateAsset<UMaterialInstanceConstant, UMaterialInstanceConstantFactoryNew>();
-		UMaterialInstanceConstantFactoryNew* Factory = NewObject<UMaterialInstanceConstantFactoryNew>();
+		if (!MI) return;
-
-		UObject* NewAsset = AssetTools.CreateAsset(Name, PackagePath, UMaterialInstanceConstant::StaticClass(), Factory);
-		UMaterialInstanceConstant* MI = Cast<UMaterialInstanceConstant>(NewAsset);
-		if (!MI)
-		{
-			Result.Appendf(TEXT("ERROR: Failed to create Material Instance '%s' in '%s'\n"), *Name, *PackagePath);
-			return;
-		}
 
 		// Set parent.
 		TArray<UObject*> Chain = { MI };

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/Material_Create.h

@@ -7,8 +7,7 @@
 #include "Materials/Material.h"
 #include "MaterialDomain.h"
 #include "Factories/MaterialFactoryNew.h"
-#include "AssetToolsModule.h"
+#include "MCPPackageMaker.h"
-#include "IAssetTools.h"
 #include "Material_Create.generated.h"
 
 
@@ -22,11 +21,8 @@ class UMCP_Material_Create : public UObject, public IMCPHandler
 	GENERATED_BODY()
 
 public:
-	UPROPERTY(meta=(Description="Name for the new material asset"))
+	UPROPERTY(meta=(Description="Full asset path for the new material (e.g. '/Game/Materials/M_Gold')"))
-	FString Name;
+	FString AssetPath;
-
-	UPROPERTY(meta=(Description="Package path where the asset will be created (must start with /Game)"))
-	FString PackagePath;
 
 	UPROPERTY(meta=(Optional, Description="Material domain: Surface, DeferredDecal, LightFunction, Volume, PostProcess, UI"))
 	FString Domain;
@@ -44,42 +40,29 @@ public:
 
 	virtual void Handle(FStringBuilderBase& Result) override
 	{
-		if (!PackagePath.StartsWith(TEXT("/Game")))
+		MCPErrorCallback Error(Result);
-		{
+
-			Result.Append(TEXT("ERROR: PackagePath must start with '/Game'\n"));
+		MCPPackageMaker Maker(AssetPath, Error);
-			return;
+		if (!Maker.Ok()) return;
-		}
 
 		// Parse optional enum properties before creating the asset.
 		EMaterialDomain ParsedDomain = MD_Surface;
 		if (!Domain.IsEmpty())
 		{
-			if (!MCPUtils::StringToEnum(Domain, ParsedDomain, Result, TEXT("MD_")))
+			if (!MCPUtils::StringToEnum(Domain, ParsedDomain, Error, TEXT("MD_")))
 				return;
 		}
 
 		EBlendMode ParsedBlendMode = BLEND_Opaque;
 		if (!BlendMode.IsEmpty())
 		{
-			if (!MCPUtils::StringToEnum(BlendMode, ParsedBlendMode, Result, TEXT("BLEND_")))
+			if (!MCPUtils::StringToEnum(BlendMode, ParsedBlendMode, Error, TEXT("BLEND_")))
 				return;
 		}
 
-		// Check if an asset with this name already exists.
-		MCPAssets<UMaterial> ExistCheck;
-		if (!ExistCheck.Exact(Name).Errors(Result).EAny().Info()) return;
-
 		// Create via IAssetTools + factory.
-		IAssetTools& AssetTools = FModuleManager::LoadModuleChecked<FAssetToolsModule>("AssetTools").Get();
+		UMaterial* MaterialObj = Maker.CreateAsset<UMaterial, UMaterialFactoryNew>();
-		UMaterialFactoryNew* Factory = NewObject<UMaterialFactoryNew>();
+		if (!MaterialObj) return;
-		UObject* NewAsset = AssetTools.CreateAsset(Name, PackagePath, UMaterial::StaticClass(), Factory);
-
-		UMaterial* MaterialObj = Cast<UMaterial>(NewAsset);
-		if (!MaterialObj)
-		{
-			Result.Appendf(TEXT("ERROR: Failed to create Material '%s' in '%s'\n"), *Name, *PackagePath);
-			return;
-		}
 
 		// Apply optional properties.
 		TArray<UObject*> Chain = { MaterialObj };

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/Property_Dump.h

@@ -44,30 +44,45 @@ public:
 
 		TArray<FProperty*> Props = MCPUtils::SearchProperties(Template, Query, CPF_Edit, Local);
 
-		UStruct* CurrentOwner = nullptr;
+		// Group properties by category.
+		TMap<FString, TArray<FProperty*>> ByCategory;
 		for (FProperty* Prop : Props)
 		{
-			FString PropName = MCPUtils::FormatName(Prop);
+			FString Category = Prop->HasMetaData(TEXT("Category")) ? Prop->GetMetaData(TEXT("Category")) : FString();
+			ByCategory.FindOrAdd(Category).Add(Prop);
+		}
 
-			// Print section heading when the owning class changes.
+		// Sort category names, putting empty category last.
-			UStruct* Owner = Prop->GetOwnerStruct();
+		TArray<FString> Categories;
-			if (Owner != CurrentOwner)
+		ByCategory.GetKeys(Categories);
+		Categories.Sort([](const FString& A, const FString& B) {
+			if (A.IsEmpty()) return false;
+			if (B.IsEmpty()) return true;
+			return A < B;
+		});
+
+		for (const FString& Category : Categories)
+		{
+			if (Category.IsEmpty())
+				Result.Append(TEXT("\nUncategorized:\n"));
+			else
+				Result.Appendf(TEXT("\n%s:\n"), *Category);
+
+			for (FProperty* Prop : ByCategory[Category])
 			{
-				CurrentOwner = Owner;
+				FString PropName = MCPUtils::FormatName(Prop);
-				Result.Appendf(TEXT("\nFrom %s:\n\n"), *MCPUtils::FormatName(Owner));
+				FString ValueStr = MCPUtils::GetPropertyValueText(Template, Prop);
+
+				if (Truncate && (ValueStr.Len() > 80))
+					ValueStr = ValueStr.Left(80) + TEXT("...");
+
+				bool bEditable = !Prop->HasAnyPropertyFlags(CPF_EditConst);
+				Result.Appendf(TEXT("    %s %s %s = %s\n"),
+					bEditable ? TEXT("editable") : TEXT("readonly"),
+					*MCPUtils::FormatPropertyType(Prop),
+					*PropName,
+					*ValueStr);
 			}
-
-			FString ValueStr = MCPUtils::GetPropertyValueText(Template, Prop);
-
-			if (Truncate && (ValueStr.Len() > 80))
-				ValueStr = ValueStr.Left(80) + TEXT("...");
-
-			bool bEditable = !Prop->HasAnyPropertyFlags(CPF_EditConst);
-			Result.Appendf(TEXT("    %s %s %s = %s\n"),
-				bEditable ? TEXT("editable") : TEXT("readonly"),
-				*MCPUtils::FormatPropertyType(Prop),
-				*PropName,
-				*ValueStr);
 		}
 
 		if (Props.IsEmpty())

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/Struct_Create.h

@@ -7,9 +7,8 @@
 #include "StructUtils/UserDefinedStruct.h"
 #include "Kismet2/BlueprintEditorUtils.h"
 #include "UserDefinedStructure/UserDefinedStructEditorData.h"
-#include "AssetToolsModule.h"
-#include "IAssetTools.h"
 #include "Factories/StructureFactory.h"
+#include "MCPPackageMaker.h"
 #include "Struct_Create.generated.h"
 
 
@@ -35,11 +34,8 @@ class UMCP_Struct_Create : public UObject, public IMCPHandler
 	GENERATED_BODY()
 
 public:
-	UPROPERTY(meta=(Description="Name for the new struct asset"))
+	UPROPERTY(meta=(Description="Full asset path for the new struct (e.g. '/Game/DataTypes/S_MyStruct')"))
-	FString Name;
+	FString AssetPath;
-
-	UPROPERTY(meta=(Description="Package path where the asset will be created (must start with /Game)"))
-	FString PackagePath;
 
 	UPROPERTY(meta=(Optional, Description="Array of initial properties, each with 'name' and 'type' fields"))
 	FMCPJsonArray Properties;
@@ -51,27 +47,14 @@ public:
 
 	virtual void Handle(FStringBuilderBase& Result) override
 	{
-		if (!PackagePath.StartsWith(TEXT("/Game")))
+		MCPErrorCallback Error(Result);
-		{
-			Result.Append(TEXT("ERROR: PackagePath must start with '/Game'\n"));
-			return;
-		}
 
-		// Check if an asset with this name already exists.
+		MCPPackageMaker Maker(AssetPath, Error);
-		MCPAssets<UUserDefinedStruct> ExistCheck;
+		if (!Maker.Ok()) return;
-		if (!ExistCheck.Exact(Name).Errors(Result).EAny().Info()) return;
 
 		// Create the struct using the AssetTools factory.
-		IAssetTools& AssetTools = FModuleManager::LoadModuleChecked<FAssetToolsModule>("AssetTools").Get();
+		UUserDefinedStruct* NewStruct = Maker.CreateAsset<UUserDefinedStruct, UStructureFactory>();
-		UStructureFactory* Factory = NewObject<UStructureFactory>();
+		if (!NewStruct) return;
-		UObject* NewAsset = AssetTools.CreateAsset(Name, PackagePath, UUserDefinedStruct::StaticClass(), Factory);
-
-		UUserDefinedStruct* NewStruct = Cast<UUserDefinedStruct>(NewAsset);
-		if (!NewStruct)
-		{
-			Result.Appendf(TEXT("ERROR: Failed to create struct '%s' in '%s'\n"), *Name, *PackagePath);
-			return;
-		}
 
 		// Add properties if specified.
 		int32 PropsAdded = 0;

Plugins/BlueprintMCP/Source/BlueprintMCP/Public/MCPPackageMaker.h

@@ -0,0 +1,77 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "MCPUtils.h"
+#include "UObject/Package.h"
+#include "AssetToolsModule.h"
+#include "IAssetTools.h"
+
+// Helper for creating new asset packages. Validates the path and checks for
+// conflicting assets in the constructor. Call Ok() to check, then Make() to
+// actually create the UPackage.
+class MCPPackageMaker
+{
+public:
+	MCPPackageMaker(const FString& InFullPath, MCPErrorCallback InError)
+		: FullPath(InFullPath)
+		, Error(InError)
+	{
+		// Path must start with /Game.
+		if (!FullPath.StartsWith(TEXT("/Game")))
+		{
+			Error.SetError(FString::Printf(TEXT("Package path '%s' must start with '/Game'"), *FullPath));
+			bError = true;
+			return;
+		}
+
+		// Check for an existing asset at this path.
+		if (FindObject<UPackage>(nullptr, *FullPath))
+		{
+			Error.SetError(FString::Printf(TEXT("An asset already exists at '%s'"), *FullPath));
+			bError = true;
+			return;
+		}
+	}
+
+	bool Ok() const { return !bError; }
+
+	bool Make()
+	{
+		if (bError) return false;
+		Pkg = CreatePackage(*FullPath);
+		if (!Pkg)
+		{
+			Error.SetError(FString::Printf(TEXT("Failed to create package at '%s'"), *FullPath));
+			bError = true;
+			return false;
+		}
+		return true;
+	}
+
+	UPackage* Package() const { return Pkg; }
+	FString Name() const { return FPackageName::GetShortName(FullPath); }
+
+	template<typename AssetClass, typename FactoryClass>
+	AssetClass* CreateAsset()
+	{
+		if (bError) return nullptr;
+		IAssetTools& AssetTools = FModuleManager::LoadModuleChecked<FAssetToolsModule>("AssetTools").Get();
+		FactoryClass* Factory = NewObject<FactoryClass>();
+		FString PkgPath = FPackageName::GetLongPackagePath(FullPath);
+		FString AssetName = FPackageName::GetShortName(FullPath);
+		UObject* NewAsset = AssetTools.CreateAsset(AssetName, PkgPath, AssetClass::StaticClass(), Factory);
+		AssetClass* Result = Cast<AssetClass>(NewAsset);
+		if (!Result)
+		{
+			Error.SetError(FString::Printf(TEXT("Failed to create asset at '%s'"), *FullPath));
+			bError = true;
+		}
+		return Result;
+	}
+
+private:
+	FString FullPath;
+	MCPErrorCallback Error;
+	UPackage* Pkg = nullptr;
+	bool bError = false;
+};