n2c-orchestrator

name: n2c-orchestrator description: Lead orchestrator for Blueprint to C++ conversion using multi-agent pipeline. Triggers on "blueprint to cpp", "convert blueprint", "nativize", "n2c-orchestrator".

N2C Lead Orchestrator

Coordinates sub-agents for Blueprint to C++ conversion with full inheritance support.

Pipeline Overview

ORCHESTRATOR (this skill)
    │
    ├──[0] Detect Blueprint Inheritance Chain
    │        └─► Recursively find all BP parents until C++ base
    │
    ├──[1] User Confirmation
    │        └─► Confirm output paths and conversion scope
    │
    ├──[2] Convert Each Blueprint (parent-first order)
    │        ├─► n2c-json-export
    │        ├─► n2c-context-gatherer
    │        ├─► n2c-code-generator
    │        └─► n2c-validator
    │
    ├──[3] Write Files (after user confirmation)
    │
    └──[4] Build Verification
             └─► Compile S2Editor to verify code

Phase 0: Detect Blueprint Inheritance Chain

Before converting, trace the full inheritance chain:

Detection Logic:

1. Use MCP blueprint_read or export JSON to get parent_class
2. If parent starts with /Game/ → it's a Blueprint parent
3. Recursively trace until reaching a C++ class (no /Game/ prefix)

Example Chain:

GA_Companion_StunStrike (Blueprint)
    └─► GA_CompanionAnimDrivenAttack (Blueprint parent)
        └─► USipherPhysicalAbility (C++ base)

Ask User (using AskUserQuestion tool):

Blueprint Inheritance Detected

GA_Companion_StunStrike inherits from:
  → GA_CompanionAnimDrivenAttack (Blueprint)
    → USipherPhysicalAbility (C++)

How should we handle the Blueprint parent?

Options:
1. Convert Both (Recommended) - Convert parent BP to C++ first, then child inherits from it
2. Flatten - Merge parent BP logic into child C++ class
3. Skip Parent - Convert only child, inherit from USipherPhysicalAbility directly

Phase 1: User Confirmation - Output Paths

Before generating code, confirm output paths with user:

Default Path Mapping:

Ask User (using AskUserQuestion tool):

Confirm Output Paths

The following files will be generated:

1. GA_CompanionAnimDrivenAttack (parent)
   Header: Source/S2/Public/GameplayAbilities/GA_CompanionAnimDrivenAttack.h
   Impl:   Source/S2/Private/GameplayAbilities/GA_CompanionAnimDrivenAttack.cpp

2. GA_Companion_StunStrike (child)
   Header: Source/S2/Public/GameplayAbilities/GA_Companion_StunStrike.h
   Impl:   Source/S2/Private/GameplayAbilities/GA_Companion_StunStrike.cpp

Options:
1. Confirm paths
2. Change paths (specify new locations)

If user wants to change paths, accept their input and update accordingly.

Phase 2: Convert Blueprints (Parent-First Order)

For each Blueprint in the chain (starting from topmost parent):

Step 2.1: JSON Export

Use Task tool with:

• description: "N2C JSON Export"
• subagent_type: "general-purpose"
• prompt: Prompt template below

You are the N2C JSON Export agent. Follow ../n2c-json-export/SKILL.md

Input:
- blueprintPath: {BLUEPRINT_PATH}
- outputPath: G:/s2/Saved/NodeToCode/Export/{ASSET_NAME}.json

Execute via PowerShell:
powershell -Command "& 'G:/UnrealEngine/Engine/Binaries/Win64/UnrealEditor-Cmd.exe' 'G:/s2/S2.uproject' '-run=N2CExport' '-Blueprint={BLUEPRINT_PATH}' '-Output={OUTPUT_PATH}' '-Depth=2' '-Pretty' '-unattended' '-nosplash' '-nullrhi'"

Return: success, jsonPath, metadata (baseClass, referencedTypes, graphCount)

Step 2.2: Context Gathering

Use Task tool with:

• description: "N2C Context Gatherer"
• subagent_type: "general-purpose"
• prompt: Prompt template below

You are the N2C Context Gatherer agent. Follow ../n2c-context-gatherer/SKILL.md

Input:
- jsonPath: {JSON_PATH}
- metadata: {METADATA_FROM_STEP_1}
- previouslyGeneratedClasses: {LIST_OF_PARENT_CLASSES_ALREADY_CONVERTED}

Search directories:
- Source/S2/Public/**/*.h
- Plugins/Sipher*/Source/*/Public/**/*.h
- Plugins/Frameworks/*/Source/*/Public/**/*.h

Return: includeMap, baseClassContext (virtualMethods), apiPatterns, potentialConflicts

Step 2.3: Code Generation

Use Task tool with:

• description: "N2C Code Generator"
• subagent_type: "general-purpose"
• prompt: Prompt template below

You are the N2C Code Generator agent. Follow ../n2c-code-generator/SKILL.md

Input:
- jsonPath: {JSON_PATH}
- context: {CONTEXT_FROM_STEP_2}
- outputClassName: U{ASSET_NAME}
- baseClass: {PARENT_CPP_CLASS_OR_PREVIOUSLY_CONVERTED}
- moduleName: S2

CRITICAL: If parent was converted in this session, inherit from the converted C++ class.

Return: header, implementation, notes, buildDependencies

Step 2.4: Validation

Use Task tool with:

• description: "N2C Validator"
• subagent_type: "general-purpose"
• prompt: Prompt template below

You are the N2C Validator agent. Follow ../n2c-validator/SKILL.md

Input:
- header: {GENERATED_HEADER}
- implementation: {GENERATED_IMPLEMENTATION}
- context: {CONTEXT}
- outputPaths: {USER_CONFIRMED_PATHS}

Validation checks:
1. .generated.h is last include in header
2. Own header is first include in .cpp
3. Include paths exist
4. Method signatures match base class
5. Apply known pattern fixes
6. No variable shadowing

Return: valid, fixedHeader, fixedImplementation, appliedFixes, warnings

Phase 3: Write Files

After all Blueprints are validated:

1. Show final confirmation:

Ready to write files:

1. GA_CompanionAnimDrivenAttack
   - Source/S2/Public/GameplayAbilities/GA_CompanionAnimDrivenAttack.h (NEW)
   - Source/S2/Private/GameplayAbilities/GA_CompanionAnimDrivenAttack.cpp (NEW)

2. GA_Companion_StunStrike
   - Source/S2/Public/GameplayAbilities/GA_Companion_StunStrike.h (EXISTS - will backup)
   - Source/S2/Private/GameplayAbilities/GA_Companion_StunStrike.cpp (EXISTS - will backup)

Proceed? [Y/n]

2. Create directories if needed
3. Backup existing files with .bak extension
4. Write all files

Phase 4: Build Verification

After writing files, compile to verify:

powershell -Command "& 'G:/UnrealEngine/Engine/Build/BatchFiles/Build.bat' S2Editor Win64 Development -Project='G:/s2/S2.uproject' -WaitMutex"

Check build result:

• Success: Report completion
• Failure: Show errors, offer to rollback .bak files

Phase 5: Final Report

Blueprint Conversion Complete

Converted 2 Blueprints:

1. GA_CompanionAnimDrivenAttack → UGA_CompanionAnimDrivenAttack
   - Source/S2/Public/GameplayAbilities/GA_CompanionAnimDrivenAttack.h
   - Source/S2/Private/GameplayAbilities/GA_CompanionAnimDrivenAttack.cpp
   - Base: USipherPhysicalAbility

2. GA_Companion_StunStrike → UGA_Companion_StunStrike
   - Source/S2/Public/GameplayAbilities/GA_Companion_StunStrike.h
   - Source/S2/Private/GameplayAbilities/GA_Companion_StunStrike.cpp
   - Base: UGA_CompanionAnimDrivenAttack (converted above)

Build Status: SUCCESS
Validation Fixes Applied: 3
Warnings: 0

Next Steps:
- Delete original Blueprint assets if no longer needed
- Update any Blueprint references to use new C++ classes

Error Handling

Rollback on Build Failure

If build fails after writing files:

Build Failed - Compilation Errors

Error: GA_Companion_StunStrike.cpp(45): error C2039: 'MakeEffectContext' is not a member of 'UAbilitySystemComponent'

Options:
1. Rollback - Restore .bak files and delete generated code
2. Keep files - Leave generated code for manual fixing
3. Retry generation - Re-run code generator with error context

Inheritance Chain Conversion Order

When converting a chain like:

Child (BP) → Parent (BP) → Grandparent (BP) → CppBase (C++)

Convert in order:

1. Grandparent → inherits from CppBase
2. Parent → inherits from converted Grandparent
3. Child → inherits from converted Parent

This ensures each C++ class has its parent available during generation.

Legacy Metadata

invocable: true