UnrealMCP — AI Bridge for Unreal Engine 5

Remove a modifier from a mapping in an Input Mapping Context. Args: context_path: Path to the IMC asset mapping_index: Index of the mapping modifier_index: Index of the modifier within that mapping

Remove a trigger from a mapping in an Input Mapping Context. Args: context_path: Path to the IMC asset mapping_index: Index of the mapping trigger_index: Index of the trigger within that mapping

Remove a single trait from a Mass Entity Config without affecting other traits. Identify the trait by EITHER trait_index OR trait_class (not both required). Args: asset_path: Path to MassEntityConfigAsset trait_index: Index of the trait to remove trait_class: Class name or full path (e.g. "MassMovementTrait")

Remove a pin from a Custom HLSL node and rebuild its signature.

Remove an emitter from a Niagara System by name. Args: system_path: Path to the Niagara System asset emitter_name: Name of the emitter to remove

Remove a module from an emitter's script usage stack. Args: system_path: Path to the Niagara System asset emitter_name: Name of the target emitter module_name: Name of the module to remove script_usage: Stack the module is in — EmitterSpawn, EmitterUpdate, ParticleSpawn, ParticleUpdate, SystemSpawn, SystemUpdate

Remove a dynamic pin from any node in a scratch pad graph.

Remove a renderer from an emitter by index. Args: system_path: Path to the Niagara System asset emitter_name: Name of the target emitter renderer_index: Index of the renderer to remove (from get_niagara_emitters)

Remove a named input or output parameter from a Niagara script.

Remove a user parameter from a Niagara System. Args: system_path: Path to the Niagara System asset parameter_name: Name of the parameter to remove

Remove a property binding by index. Args: asset_path: Content path to the StateTree asset binding_index: Index of the binding to remove

Remove a task, evaluator, or condition by GUID. Args: asset_path: Content path to the StateTree asset node_guid: GUID of the node to remove

Remove a tree-level parameter by name. Args: asset_path: Content path to the StateTree asset name: Parameter name to remove

Remove a state and all its children from the tree. Args: asset_path: Content path to the StateTree asset state: State index path state_name: State name state_guid: State GUID

Remove a transition from a state. Args: asset_path: Content path to the StateTree asset transition_index: Index of the transition to remove state: State index path state_name: State name state_guid: State GUID

Remove a widget and its children. Cannot remove the root widget.

Rename or move an asset. UE5 automatically fixes all references.

Rename a function in a Blueprint.

Rename a row in-place (preserves row order).

Rename a Custom HLSL pin and update references inside the HLSL source. Braced references ("{OldName}") inside the HLSL code are rewritten to "{NewName}" via a whole-word replacement after the pin is renamed.

Rename a dynamic pin on any node in a scratch pad graph. For Custom HLSL nodes, braced references inside the HLSL source ("{OldName}") are rewritten automatically.

Rename a scratch pad module on a Niagara System.

Rename a script parameter in-place across both asset and edit-copy graphs.

Rename a widget (fixes up Blueprint variable tracking if bIsVariable).

Move an emitter to a new position in the system's emitter list. Args: system_path: Path to the Niagara System asset emitter_name: Name of the emitter to move new_index: Target index (0-based) in the emitter list

Move a module to a new position within its script usage stack. Args: system_path: Path to the Niagara System asset emitter_name: Name of the target emitter module_name: Name of the module to move script_usage: Stack the module is in new_index: Target index (0-based) within the stack

Discover built-in dynamic-input script asset paths via AssetRegistry. Replaces guessed paths like "/Niagara/Modules/DynamicInputs/UniformRangedFloat" (which vary across UE versions) with a live scan. Returns all UNiagaraScript assets with Usage=DynamicInput matching the filter. Args: name_filter: Case-insensitive substring on asset name (e.g. "Random", "UniformRanged", "Mask", "MultiplyVector") exact_name: If set, return only the asset whose name equals this max_results: Cap on returned entries (default 20)

Save all unsaved (dirty) assets.

Save a specific asset to disk.

Search for UClass types by name filter and parent class constraint. Returns full /Script/Module.ClassName paths needed for _ClassName in trait editing. Use this to find the correct class_path before calling set_data_asset_property with Mass Entity Config traits. Args: filter: Case-insensitive substring match on class name (e.g. "Conveyor", "Miner") parent_class: Only return subclasses of this class (e.g. "MassEntityTraitBase" for traits, "MassFragment" for fragments, "MassTag" for tags, "MassProcessor" for processors). Empty = search all classes. max_results: Maximum results to return (default 50) include_properties: If true, also return each class's editable UPROPERTY names, types, and default values. Use sparingly — adds tokens per result. Examples: search_class_paths(filter="Conveyor", parent_class="MassEntityTraitBase") → finds MassConveyorBeltTrait with class_path "/Script/Jiggify.MassConveyorBeltTrait" search_class_paths(filter="Pipeline", parent_class="MassFragment") → finds all pipeline-related fragments search_class_paths(parent_class="MassEntityTraitBase") → lists ALL available traits (no filter)

Search for Material Functions by name. Args: filter: Name substring to match (e.g. "Blend", "Normal", "Fresnel") path: Content Browser path to search in (default "/Game") max_results: Maximum results to return (default 50) include_engine: Include engine built-in material functions

Search Niagara script assets by usage + name filter. Dedicated shortcut for finding module / dynamic_input / function script assets so you can pass the result directly to add_niagara_module or set_niagara_dynamic_input. Args: filter: Optional name/path substring usage: "module", "dynamic_input", or "function" (default) include_engine: When false, restricts scan to /Game max_results: Cap on returned entries

Search for classes that can be used as Blueprint parents. Use this BEFORE create_blueprint to find the correct parent class name. Returns a filtered list of matching classes — never dumps all classes. Args: filter: Keyword to search for (e.g. "Miner", "Actor", "Pawn", "Widget") max_results: Maximum results (default 20, max 100) include_blueprint_classes: Also include Blueprint-generated classes (default True)

Search for nodes across the entire StateTree by class name or category. Answers questions like: "Is MassEnemyAttackTask used?" or "Which states have conditions?" Returns each match with its location (which state, evaluator list, transition, etc.). Args: asset_path: Content path to the StateTree asset class_filter: Substring filter on node class name (e.g. "Attack", "CompareInt") category: Filter by node category: "task", "evaluator", "condition", "consideration", "global_task" (empty = search all categories)

Set a property at any nested path on a placed level actor instance. Writes to the actual placed actor (not its CDO/Blueprint defaults), so editor overrides are preserved. Walks struct fields and array indices, fires PostEditChangeProperty on the top-level property, and marks the level dirty. Args: actor_label: Actor's display label in the Outliner (or its UObject name). property_path: Dot-separated property path. Examples: "Settings.BloomIntensity" "Settings.ColorGradingHighlights.Gain" "Tags[0]" "Settings.bOverride_BloomIntensity" property_value: The value to write. Accepts: - Numbers, bools, strings for primitives and enums - JSON object for structs ({"R":1.0,"G":0.5,"B":0.0,"A":1.0} for FLinearColor) - UE text format string for structs ("(R=1.0,G=0.5,B=0.0,A=1.0)") - Asset path string for object/class references component_name: Optional. If set, the path is resolved starting from a component on the actor instead of the actor itself. Returns: actor identification + the resolved top-level FProperty name.

Set an actor's location, rotation, and/or scale.

Set a property on an asset. Args: property_name: Property name (e.g. "two_sided", "blend_mode") property_value: JSON-encoded value (e.g. "true", "0.5", '"translucent"')

Set default property values on a Blueprint's generated class CDO. Works on ALL editable properties — C++ parent properties and BP-defined variables alike (e.g. SlotWidgetClass, MaxHealth, bCanFly). Set a single property with property_name + property_value, or set multiple at once with a properties dict. Both can be used in the same call. Args: blueprint_path: Full path to blueprint (e.g. "/Game/Blueprints/BP_MyActor") property_name: Name of a single property to set property_value: Value for the single property (JSON-compatible) properties: Dict of property names to values for batch setting

Set a node property or perform semantic editing. Semantic actions (pass via 'action'): add_pin, remove_pin, set_enum_type, set_pin_type, set_value_type, set_cast_target, set_function_call, set_event_type Each action has associated params (pin_type, pin_name, enum_type, new_type, target_type, target_function, target_class, event_type).

Modify properties of an existing Blueprint variable. All parameters besides blueprint_name and variable_name are optional — only provided values are changed.

Set multiple properties in a single call (one load + one save). More efficient than calling set_data_asset_property in a loop. Same value format as set_data_asset_property.

Set a single property on a data asset. Supports all types: primitives, enums, FName, FText, structs ({"tagName": "..."}), arrays, object refs ("/Game/..."), soft refs, and None (clears reference). property_name is case-sensitive (exact FProperty name). **Mass Entity Config — Editing Trait Properties:** To edit trait properties on a MassEntityConfigAsset (e.g., BeltSpeed, SlotCount), set property_name="Config" with a JSON value containing the Traits array. Each trait needs a "_ClassName" with FULL path "/Script/Module.ClassName". Example — set BeltSpeed on a conveyor config: set_data_asset_property( asset_path="/Game/.../DA_ConveyorMassConfig_Mk2", property_name="Config", property_value={ "Traits": [{"_ClassName": "/Script/Jiggify.MassConveyorBeltTrait", "BeltSpeed": 200}] } ) IMPORTANT: _ClassName MUST be full path ("/Script/Jiggify.MassConveyorBeltTrait"), NOT short name ("MassConveyorBeltTrait"). Short names create wrong base class. For configs with multiple traits, include ALL traits in the array (entire array is replaced). Only set the properties you want to change — others use C++ defaults.

Set properties on an Input Action. Args: asset_path: Path to the InputAction asset value_type: Convenience shortcut — Boolean | Axis1D | Axis2D | Axis3D properties: Dict of property names to values (e.g. {"bConsumeInput": false})

Change the key or action on an existing mapping in an IMC. Args: context_path: Path to the IMC asset index: Mapping index to modify key: New key name (optional) action_path: New action path (optional)

Modify properties on an EXISTING trait in a Mass Entity Config in-place. Never replaces the Traits array, never creates new UObjects. Only touches the specific properties you provide — all other trait values stay intact. Uses Unreal's own ImportText reflection so it supports ANY property type (structs, arrays, object refs, meshes, LOD params, enums, etc.). Identify the trait by EITHER trait_index OR trait_class (not both required). Set properties with EITHER property_name+property_value (single) OR properties dict (batch). Args: asset_path: Path to MassEntityConfigAsset trait_index: Index of the trait in the Traits array (from get_mass_config_traits) trait_class: Class name or full path (e.g. "MassMovementTrait" or "/Script/MassMovement.MassMovementTrait") property_name: Single property to set (requires property_value) property_value: Value for property_name. For structs use dict, for object refs use asset path string, for enums use name string. properties: Batch set multiple properties {name: value, ...} Examples: # Set MaxSpeed on movement trait by class name set_mass_config_trait_property( asset_path="/Jiggify/Game/.../DA_Config", trait_class="MassMovementTrait", property_name="Movement", property_value={"MaxSpeed": 300, "MaxAcceleration": 500} ) # Set LODMaxCount on visualization trait by index set_mass_config_trait_property( asset_path="/Jiggify/Game/.../DA_Config", trait_index=4, property_name="LODParams", property_value={"LODMaxCount": [2000, 5000, 10000, 2147483647]} ) # Batch set multiple properties set_mass_config_trait_property( asset_path="/Jiggify/Game/.../DA_Config", trait_class="MassEnemyTrait", properties={"MaxHealth": 50, "BaseDamage": 10, "MoveSpeed": 400} )

Set a property on an existing material expression node. Accepts snake_case ("parameter_name") or PascalCase ("ParameterName"). Common properties: parameter_name, default_value, slider_min, slider_max, group, texture, code, description, output_type, inputs, add_inputs, outputs, SpeedX, SpeedY, CoordinateIndex, R, Constant.

Modify an existing FunctionInput node's properties. Args: function_path: Full path to existing material function node_index: Index of the FunctionInput node (from get_material_function_info) input_name: New pin name input_type: New type (Scalar/Vector2/Vector3/Vector4/Texture2D/TextureCube/ Texture2DArray/VolumeTexture/StaticBool/MaterialAttributes/ TextureExternal/Bool/Substrate) description: New tooltip sort_priority: New display order use_preview_as_default: Use preview value as default preview_value: JSON array for default value (e.g. "[0.5]", "[1.0, 0.0, 0.0, 1.0]")

Modify an existing FunctionOutput node's properties. Args: function_path: Full path to existing material function node_index: Index of the FunctionOutput node (from get_material_function_info) output_name: New pin name description: New tooltip sort_priority: New display order

Set a parameter override on a Material Instance. Args: param_type: scalar | vector | texture | static_switch value: JSON-encoded — float, [r,g,b,a], "/Game/path", or true/false

Bulk-set material-level properties in one call. Args: blend_mode: opaque | masked | translucent | additive | modulate | alpha_composite | alpha_holdout shading_model: default_lit | unlit | subsurface | clear_coat | etc. recompile: Recompile after setting properties (default True)