Unreal 5.8's native toolsets can start PIE but cannot measure anything, so an agent asked to fix frame rate is guessing. frame_timing() gives it a CPU-vs-GPU-bound verdict first, which decides whether optimising the GPU would do anything at all. Everything else follows the same rule: agents use the engine's toolsets for basic asset and actor work, and VibeUE for the domains they do not cover.
An expansion of Unreal Engine 5.8's own MCP server. VibeUE registers its services into the engine's ToolsetRegistry and ModelContextProtocol endpoint, so there is no second server to run.
- Terrain and world — landscape sculpting, heightmaps and splines, auto-materials with RVT, foliage, FPS map blockout, and real-world terrain from GPS coordinates
- Audio — MetaSound and SoundCue graph authoring
- Animation assets — AnimSequence keyframe editing, AnimMontage authoring, AnimBP state machines, and skeleton bone, socket and retarget editing
- Behavior Tree and Blackboard authoring by structural path, with JSON round-trips and validate/repair, guarded against edits while PIE or an editor window is open
- Higher-order Blueprint authoring — timelines, event dispatchers, delegates, custom-event pins and a batch build_graph builder
- PerformanceService — frame_timing() returns the Game/Render/GPU/RHI split with a CPU-vs-GPU-bound verdict, plus Unreal Insights capture through start_trace, stop_trace and get_trace_status, and analyse() to read the trace and log back
- TransactionService wrapping the editor's transaction buffer, so an agent can group and roll back its own edits
- execute_python_code plus discover_python_module, discover_python_class and list_python_subsystems — one round-trip reaches every service and the whole unreal.* API
- deep_research and terrain_data, and around 36 markdown skill packs served through Unreal's native AgentSkill system
Unreal Engine 5.8 or newer and Git. Unreal's native MCP has to be set up first — enable the Unreal MCP and Editor Tools plugins, then turn on Auto Start Server; the default endpoint is http://127.0.0.1:8000/mcp. Clone VibeUE into your project's Plugins folder and build with the supplied script. A free API key, set in Editor Preferences, unlocks the real-world terrain tools; everything else works without one. The endpoint is loopback-only with no authentication, so it is same-machine use.
