UECortex

UECortex

Native Unreal Engine 5 plugin that runs a full MCP (Model Context Protocol) server inside the Unreal Editor. Control your project directly from Claude Code, VS Code, or any MCP client — no Python sidecar, no Node.js process, no external dependencies.

169 built-in tools across 17 categories, plus a Python-backed dynamic tool layer.

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Quick Start

1. Install

Copy the UECortex folder into your project's Plugins/ directory and enable it in your .uproject:

{
  "Name": "UECortex",
  "Enabled": true
}

Reopen the project. The server starts automatically on editor launch.

2. Connect

Claude Code:

claude mcp add uecortex --transport http http://localhost:7777/mcp

VS Code (.vscode/mcp.json):

{ "servers": { "uecortex": { "url": "http://localhost:7777/mcp" } } }

Claude Desktop (claude_desktop_config.json):

{ "mcpServers": { "uecortex": { "url": "http://localhost:7777/mcp" } } }

Health check:

GET http://localhost:7777/health

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Tool Categories

Meta

Discover what's available before diving into the full tools list.

| Tool | What it does | |------|-------------| | list_tool_groups | Lists all categories with tool counts and names |

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Level & Actors

Spawn, move, delete, and inspect actors in the current level.

| Tool | What it does | |------|-------------| | actor_spawn | Spawn an actor by class at a given location/rotation/scale | | actor_spawn_on_surface | Spawn an actor snapped to the nearest surface below a point | | actor_delete | Delete an actor from the level | | actor_duplicate | Duplicate an actor with optional offset | | actor_set_transform | Set an actor's position, rotation, and/or scale | | actor_set_property | Set a property on an actor by name | | actor_get_properties | Read all exposed properties of an actor | | actor_get_selected | Get the currently selected actors in the editor | | actor_list | List all actors in the level, with optional class filter | | actor_find_by_name | Find an actor by label name | | level_get_info | Get level name, world bounds, and actor count | | line_trace | Cast a ray and return what it hits (location, normal, actor) | | viewport_focus | Focus the editor viewport on an actor | | viewport_set_camera | Set the editor camera position and rotation | | console_command | Execute an Unreal console command |

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Blueprints

Create and wire Blueprint assets programmatically.

| Tool | What it does | |------|-------------| | blueprint_create | Create a new Blueprint class from a parent class | | blueprint_add_component | Add a component (mesh, camera, audio, etc.) to a Blueprint | | blueprint_set_component_property | Set a property on a Blueprint component | | blueprint_set_cdo_property | Set a Class Default Object property | | blueprint_set_inherited_component_property | Set a property on an inherited component | | blueprint_add_variable | Add a typed variable to a Blueprint | | blueprint_set_variable | Set the default value of a Blueprint variable | | blueprint_add_function | Add a new function to a Blueprint | | blueprint_add_event_node | Add an event node (BeginPlay, Tick, custom event, etc.) | | blueprint_add_function_call | Add a function call node to a Blueprint graph | | blueprint_connect_pins | Connect two pins in a Blueprint graph | | blueprint_compile | Compile a Blueprint asset | | blueprint_get_graph | Read the full node/pin/connection graph as JSON | | blueprint_find_node | Find a node by class or title | | blueprint_set_node_property | Set a property on a graph node | | blueprint_spawn_in_level | Add a Blueprint actor to the current level | | blueprint_create_input_action | Create an Enhanced Input action and bind it | | blueprint_add_gamemode | Create a GameMode Blueprint and set it as the default |

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C++ Code Generation

Generate C++ source files and trigger editor recompilation.

| Tool | What it does | |------|-------------| | cpp_create_actor | Generate a new AActor subclass (.h + .cpp) | | cpp_create_component | Generate a new UActorComponent subclass | | cpp_create_interface | Generate a new UInterface | | cpp_create_gas_ability | Generate a UGameplayAbility subclass | | cpp_create_gas_effect | Generate a UGameplayEffect subclass | | cpp_create_attribute_set | Generate a UAttributeSet subclass | | cpp_add_include | Add a #include to an existing header | | cpp_add_uproperty | Add a UPROPERTY to an existing class | | cpp_add_ufunction | Add a UFUNCTION to an existing class | | cpp_get_class_info | Read the properties and functions declared on a class | | cpp_hot_reload | Trigger a hot reload of the project module | | cpp_run_ubt | Run a full UnrealBuildTool compile |

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Rendering & Materials

Control Lumen, Nanite, shadows, post-process, fog, sky, and materials at runtime.

| Tool | What it does | |------|-------------| | render_set_lumen | Enable/disable Lumen GI and configure quality settings | | render_get_lumen_settings | Read current Lumen settings | | render_set_nanite | Enable/disable Nanite on a Static Mesh | | render_get_nanite_settings | Read Nanite settings for a mesh | | render_set_shadows | Configure shadow distance, cascades, and quality | | render_set_post_process | Set post-process volume settings (bloom, AO, DOF, etc.) | | render_get_post_process | Read current post-process settings | | render_set_fog | Configure exponential height fog | | render_set_sky_atmosphere | Configure the sky atmosphere component | | render_set_sky_light | Set sky light intensity and source type | | render_set_ambient_occlusion | Configure SSAO settings | | render_get_materials | List materials assigned to a mesh | | render_set_material | Assign a material to a mesh slot | | render_set_material_param | Set a scalar or vector parameter on a material instance | | render_create_material_instance | Create a Material Instance from a parent material |

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Splines & Volumes

Build spline paths and place trigger/blocking volumes.

| Tool | What it does | |------|-------------| | spline_create | Create a new Spline actor in the level | | spline_add_point | Add a point to a spline | | spline_modify_point | Move or change the tangent of an existing spline point | | spline_query | Read all points and metadata from a spline | | spline_attach_mesh | Attach a Static Mesh along a spline | | volume_create | Create a volume actor (trigger, blocking, post-process, etc.) | | volume_set_properties | Resize and reposition an existing volume |

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PCG (requires Procedural Content Generation plugin)

Build and execute PCG graphs for procedural level population.

| Tool | What it does | |------|-------------| | pcg_create_graph | Create a new PCG Graph asset | | pcg_add_node | Add a node to a PCG graph | | pcg_connect_pins | Connect two nodes in a PCG graph | | pcg_disconnect_pins | Disconnect a pin connection | | pcg_get_graph | Read the full PCG graph as JSON | | pcg_get_node_params | Read the parameters on a PCG node | | pcg_set_node_param | Set a parameter on a PCG node | | pcg_set_graph_param | Set a graph-level parameter (exposed input) | | pcg_list_node_types | List all available PCG node types | | pcg_execute_graph | Trigger a PCG graph to regenerate | | pcg_create_attribute_node | Create an attribute node with a given name/type | | pcg_create_subgraph | Create a subgraph node referencing another PCG asset | | pcg_place_volume | Place a PCG Volume in the level and assign a graph | | pcg_place_seed_actor | Place a PCG seed actor for point-based generation |

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Gameplay Ability System (requires GameplayAbilities plugin)

Wire up GAS components, abilities, attributes, and gameplay tags.

| Tool | What it does | |------|-------------| | gas_add_ability_component | Add an Ability System Component to a Blueprint | | gas_grant_ability | Grant a gameplay ability to an actor | | gas_revoke_ability | Remove a granted ability from an actor | | gas_get_abilities | List all abilities granted to an actor | | gas_apply_effect | Apply a Gameplay Effect to an actor | | gas_get_active_effects | List active effects on an actor | | gas_get_attributes | Read all attribute values on an actor | | gas_set_attribute | Set an attribute value directly | | gas_add_gameplay_tag | Add a gameplay tag to an actor | | gas_remove_gameplay_tag | Remove a gameplay tag from an actor | | gas_get_gameplay_tags | List all gameplay tags on an actor | | gas_list_registered_tags | List all gameplay tags registered in the project |

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Niagara VFX

Spawn, configure, and control Niagara particle systems.

| Tool | What it does | |------|-------------| | niagara_list_systems | List all Niagara System assets in the project | | niagara_create_system | Create a new Niagara System asset | | niagara_list_emitters | List emitters inside a Niagara System | | niagara_get_parameters | Read user-exposed parameters on a Niagara System | | niagara_set_parameter | Set a parameter value on a Niagara System asset | | niagara_spawn_component | Spawn a Niagara component on an actor in the level | | niagara_activate_component | Activate or deactivate a spawned Niagara component | | niagara_set_component_parameter | Set a runtime parameter on a spawned Niagara component |

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Animation

Build Animation Blueprints, state machines, and retarget animations across skeletons.

Inspection

| Tool | What it does | |------|-------------| | anim_list_skeletons | List all Skeleton assets in the project | | anim_list_skeletal_meshes | List all Skeletal Mesh assets | | anim_list_anim_blueprints | List all Animation Blueprints | | anim_list_sequences | List AnimSequences compatible with a given skeleton | | anim_get_skeleton_bones | List every bone name and parent in a skeleton | | anim_get_anim_graph | Inspect all graphs, states, and nodes in an AnimBP |

Building Animation Blueprints

| Tool | What it does | |------|-------------| | anim_create_anim_blueprint | Create a new Animation Blueprint for a skeleton | | anim_add_state_machine | Add a State Machine node to the AnimGraph | | anim_add_state | Add a named state to a State Machine | | anim_set_state_animation | Assign an AnimSequence or BlendSpace to a state | | anim_add_transition | Add a transition arrow between two states | | anim_set_transition_condition | Wire a variable condition onto a transition rule (supports always_true) | | anim_set_entry_state | Connect the Entry node to a named state in a State Machine | | anim_compile_anim_blueprint | Compile and save an Animation Blueprint | | anim_create_locomotion_setup | One-call full locomotion setup: SM + 5 states + transitions + EventGraph wiring |

IK Retargeting (requires IKRig plugin)

| Tool | What it does | |------|-------------| | ik_rig_assign_mesh | Assign a SkeletalMesh to an IK Rig (required first step) | | ik_rig_set_retarget_root | Set the retarget root bone on an IK Rig | | ik_rig_add_retarget_chain | Add a retarget chain (limb, spine, head, etc.) | | ik_rig_remove_retarget_chain | Remove a retarget chain by name | | ik_retarget_create | Create an IK Retargeter pairing two IK Rigs with auto chain-mapping | | anim_retarget_batch | Batch-retarget a list of animations to a new skeleton |

Maintenance

| Tool | What it does | |------|-------------| | skeleton_fix_broken_references | Repair broken skeleton references across anim assets |

> Animation Blueprint workflow: add variable → add state machine → add states → assign animations → add transitions → compile → set transition conditions → compile again. Compile must happen before anim_set_transition_condition so the variable getter can resolve its type. > > For standard locomotion, use anim_create_locomotion_setup to do all of the above in a single call (includes EventGraph wiring for Speed and IsInAir).

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UMG Widgets

Create and populate Widget Blueprint UIs.

| Tool | What it does | |------|-------------| | umg_list_widgets | List all Widget Blueprint assets | | umg_create_widget | Create a new Widget Blueprint | | umg_get_widget_tree | Read the full widget tree as JSON | | umg_add_widget | Add a widget (Text, Button, Image, etc.) to the tree | | umg_set_text | Set the text content of a Text widget | | umg_set_canvas_slot | Set position and size of a widget on a Canvas Panel | | umg_set_anchor | Set anchor alignment on a Canvas Slot | | umg_set_visibility | Show or hide a widget | | umg_add_variable | Add a variable to a Widget Blueprint | | umg_compile_widget | Compile a Widget Blueprint |

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Sequencer

Build cinematic Level Sequences with camera cuts, tracks, and keyframes.

| Tool | What it does | |------|-------------| | seq_create | Create a new Level Sequence asset | | seq_list | List all Level Sequences in the project | | seq_get_info | Read sequence duration, framerate, and track layout | | seq_set_playback_range | Set the in/out point of a sequence | | seq_add_actor_binding | Bind an actor to a sequence for animation | | seq_add_transform_track | Add a transform (movement) track to a bound actor | | seq_add_keyframe | Set a keyframe value at a given frame | | seq_add_camera_cut | Add a camera cut section | | seq_add_spawnable_camera | Add a new spawnable camera actor to the sequence | | seq_add_visibility_track | Add a visibility track to a bound actor |

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Asset Management

Browse, move, copy, delete, and migrate content browser assets.

| Tool | What it does | |------|-------------| | asset_list | List assets in a folder (with optional class filter) | | asset_get_info | Get metadata for an asset (class, path, size, dependencies) | | asset_get_references | List assets that reference a given asset | | asset_get_dependencies | List assets that a given asset depends on | | asset_move | Move or rename an asset | | asset_copy | Duplicate an asset to a new path | | asset_delete | Delete an asset permanently | | asset_create_folder | Create a new content browser folder | | asset_list_redirectors | List all redirector assets in a path | | asset_fix_redirectors | Consolidate and remove redirectors | | asset_migrate | Migrate an asset and all dependencies to another project |

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Viewport & Input

Capture screenshots and drive the editor UI programmatically.

| Tool | What it does | |------|-------------| | viewport_capture | Capture the 3D viewport or full editor window as a PNG | | viewport_focus | Focus the viewport on an actor | | viewport_set_camera | Set the editor camera position and rotation | | editor_input | Simulate mouse clicks and keyboard input on the editor window |

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Fab Marketplace

Search and inspect assets from the Fab marketplace inside the editor.

| Tool | What it does | |------|-------------| | fab_login_status | Check EOS login state (required before purchases) | | fab_search | Search Fab for assets by keyword (dynamic — load once per session) | | fab_get_asset | Get full details for a Fab asset by ID (dynamic — load once per session) |

Load the dynamic tools once per session:

python_reload_tools_from_file  →  Scripts/fab_tools.json

> Purchase consent policy: fab_get_asset is information-only. Every response includes an explicit CONSENT REQUIRED notice. AI agents must never trigger a purchase, add-to-cart, or any payment action without explicit user confirmation.

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Python & Dynamic Tools

Execute Python in the editor context and register new tools at runtime without recompiling.

| Tool | What it does | |------|-------------| | python_exec | Run a Python snippet in the editor's Python environment | | python_exec_file | Run a P

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Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: ashd-007
• Source: ashd-007/UECortex
• License: MIT

Install and usage instructions live in the source repository linked above.