unreal-engine-mcp-system-plugin/FUTURE_MCP_TOOLS.md

UEBlueprintMCP — TODO / Future Tool Coverage

Domains still missing from the MCP surface. Ordered by likely value.

High value (likely soon)

pcg_op — mesh-entry & volume helpers (gap found building a PCG graph)

• set_mesh_entries{asset_path, node, entries:[{mesh, weight?}]} — populate a PCGStaticMeshSpawner's weighted selector. Today this needs raw py: the mesh_selector_parameters instance is READ-ONLY (can't reassign), so you must mutate it in place — msp.set_editor_property("mesh_entries", [...]) where each entry is a PCGMeshSelectorWeightedEntry and the mesh goes on entry.descriptor.static_mesh (struct is value-copy → set descriptor back).
• set_node_property struct coercion already handles Vector vs Rotator (3-num list, Vector tried then Rotator(roll,pitch,yaw)) — extend to Vector2D/Color/ Transform as needed.
• spawn_pcg_volume{graph, location, scale, name?} + generate{actor} — wrap PCGVolume spawn + PCGComponent.set_graph + generate(True). Note: partitioned worlds route instances to PCGPartitionActors async; count there, not on the volume.

Sequencer / Cinematics

• create_level_sequence{path}
• add_binding{seq, actor_name}, remove_binding{seq, guid}
• add_track{seq, binding_guid, track_class} (Transform, Float, Visibility, ...)
• add_key{seq, track, time, value}
• set_playback_range{seq, start, end}
• bake_to_anim_sequence{seq, binding}
• spawn_camera_actor{location, rotation, fov?}
• export_video / export_image_sequence (MovieRenderQueue)

GAS — Gameplay Ability System

• create_gameplay_ability_bp{path, parent?}
• create_attribute_set_bp{path}
• create_gameplay_effect_bp{path}
• add_gameplay_tag{tag}, remove_gameplay_tag{tag}, list_gameplay_tags{prefix?}
• gameplay_cue_create{path}

Data-driven assets

• create_gameplay_tags_table{path}
• data_table_add_row{path, row_name, fields}
• data_table_set_cell{path, row, column, value}
• data_table_read{path, row?}
• curve_table_create / add_curve
• data_asset_set_property{path, property, value}
• enum_add_value, struct_add_field

Physics / Chaos

• create_physics_asset{path, skeletal_mesh}
• create_physical_material{path, friction?, restitution?, density?}
• physics_constraint_set{component, properties}
• chaos_destruction_field_spawn

Landscape / Foliage / World Partition

• landscape_create{section_size, components_per_section, ...}
• landscape_apply_material{path}
• landscape_paint_layer{layer_name, brush_op:'add|remove', position, radius}
• foliage_add_type{static_mesh, density?, ...}
• foliage_paint{location, radius}
• world_partition_set_loading_range{actor, range}
• hlod_build{level_path}

Lighting

• build_lighting{quality:'preview|medium|high|production'}
• set_lumen{enabled, software_raytracing?, hardware_raytracing?}
• set_vsm{enabled, resolution?}
• light_set_property{actor_name, property, value}

PIE (Play-In-Editor) control

• pie_play{mode:'selected|standalone|spawn_player', num_players?}
• pie_stop{}
• pie_pause / pie_resume
• pie_eject
• pie_screenshot{path}
• pie_console_command_in_session{command}
• pie_get_log{tail?, errors_only?}

Editor / Project settings

• ini_get{config:'Engine|Game|Editor|Input', section, key}
• ini_set{config, section, key, value}
• plugin_enable{name} / plugin_disable{name} / plugin_list{}
• platform_target_settings{platform, key, value}

Source Control (Perforce/Git/Plastic)

• sc_status{paths}
• sc_checkout{paths}
• sc_revert{paths}
• sc_submit{paths, description}
• sc_get_user_settings

Cook / Package / Build

• cook_project{platform, maps?, options?}
• package_project{platform, build_config:'Development|Shipping', output_dir}
• build_lighting_then_save{level}
• check_cook_errors{platform}

Medium value

Niagara — extending the existing niagara_op

• set_module_input (currently stubbed) — write parameters into a module
• promote_to_user_parameter
• niagara_simulation_cache_record / play

UMG — extending widget_op

• bind_property{widget, property, function_path}
• create_animation{widget, name, duration}
• add_animation_track{...}
• compile_and_preview

Materials — extending material_op

• material_function_create
• material_layer_create / material_layer_blend_create
• substrate_topology helpers (if Substrate enabled)
• material_parameter_collection_create

Localization

• loc_target_create / loc_gather / loc_compile
• text_add_to_target{namespace, key, source}

Replication / Networking helpers

• bp_set_replication{bp_path, replicates?, replicates_movement?}
• bp_variable_set_replication{bp_path, name, replication:'None|Replicated|RepNotify'}

Online subsystem / OSS / EOS

• launch_dedicated_pie_server
• set_steam_appid / set_eos_credentials

Editor utility / Pipeline

• editor_utility_widget_run{path}
• editor_utility_blueprint_run{path, function}
• exec_python_file{path}
• exec_python_inline{code} — gated, dev-only

Test / Automation

• automation_run{tests:'filter'}
• gauntlet_run{config}
• unit_test_blueprint{bp_path}

Low priority / nice-to-have

• Composure (in-camera VFX)
• USD import/export
• Datasmith
• Pixel Streaming setup
• nDisplay
• VR/AR specific (OpenXR session, head tracking)
• Web Browser widget
• Movie Render Queue presets
• AI behavior debugging (LogVisualizer)
• Replay / DemoNetDriver

Architecture improvements

• Common helpers module (_common.py) for _tee, _load, _split_pkg, _vec, _rot — every module currently duplicates these.
• Versioned envelope — include schema_version in every result for client compatibility.
• Streaming results — for long-running ops (cook, lighting build), stream progress via a separate channel instead of one blocking call.
• Auto-discovery of ops — generate the JSON schemas in server.js from python module introspection, so adding an op in python automatically exposes it.
• Per-op permissions — read-only vs mutating tag in schema so a client policy can block destructive ops.
• Undo grouping — wrap each entrypoint in unreal.ScopedEditorTransaction so every mutation is one undo step.

BUG: apply_graph spawn_actor kind hard-crashes the editor (2026-06-22)

apply_graph node kind spawn_actor → UMCPGraphLibrary::SpawnSpawnActorFromClassNode() (MCPGraphLibrary.cpp:716) calls PlaceNode<UK2Node_SpawnActorFromClass>, whose blind AllocateDefaultPins() trips check(Result) in EdGraphNode.h:586 and takes the whole editor down (assertion → StaticShutdownAfterError). Reproduced 3x.

Workaround used: spawn from C++ instead (UWorld::SpawnActor) exposed via a UBlueprintFunctionLibrary, or build the deferred-spawn pair manually with call_function nodes (GameplayStatics.BeginDeferredActorSpawnFromClass + FinishSpawningActor).

Proper fix: construct UK2Node_SpawnActorFromClass via FGraphNodeCreator<> / set the Class pin before AllocateDefaultPins, or guard the assert. Until fixed, do not use the spawn_actor kind.