All 97 Operations

Complete reference for every MCP tool operation across all 6 domain tools. Use this page to quickly find the right operation and understand its parameters, annotations, and licensing tier.

Domain Overview

gengine organizes all editor operations into 6 domain tools plus two utility tools. Each domain tool accepts an operation string and a params object.

Tool Name	Domain	Ops	Summary
`unreal_world`	World & Actors	9	Spawn, move, delete, inspect actors; run console commands; capture viewport
`unreal_assets`	Asset Management	12	Search, create, rename, move, duplicate, delete assets and Blueprints
`unreal_blueprints`	Blueprint Graphs	10	Inspect, create, and edit Blueprint graphs, variables, functions, and nodes
`unreal_animation`	Animation Blueprints	8	Build state machines, add states and transitions, set animations
`unreal_character`	Characters & Stats	6	List characters, tune movement, create data assets and stat tables
`unreal_input_materials`	Input & Materials	6	Create input actions, mapping contexts, material instances
`unreal_status`	Status	1	Health check — returns plugin version and connection state
`unreal_get_ue_context`	Context System	1	Fetch accurate UE 5.7 API docs by category query

How to Call Tools

Every domain tool uses the same JSON envelope: an operation key selecting the sub-command and a params object carrying arguments.

{
  "operation": "<operation_name>",
  "params": {
    "param1": "value1",
    "param2": 42
  }
}

{
  "operation": "spawn_actor",
  "params": {
    "class_path": "/Script/Engine.PointLight",
    "name": "FillLight_01",
    "location": { "x": 200, "y": -100, "z": 300 },
    "rotation": { "pitch": 0, "yaw": 0, "roll": 0 }
  }
}

{
  "operation": "search",
  "params": {
    "query": "BP_Enemy",
    "asset_type": "Blueprint",
    "limit": 20
  }
}

Tip: Legacy tool names (unreal_spawn_actor, unreal_ue with a domain: field) still work but are not listed in MCP tool discovery. Prefer the 6-domain format for all new integrations.

Quick Reference — All Operations

Every operation across all 6 domains at a glance.

unreal_world (9 operations)

Operation	Description
`spawn_actor`	Spawn any actor class at a given location and rotation
`move_actor`	Move, rotate, or scale an actor by name
`delete_actors`	Delete actors by name array or class filter (capped at 200)
`set_property`	Set any actor property via UE reflection
`get_level_actors`	List all actors in the current level with metadata
`open_level`	Open, create, save, or list levels
`run_console_command`	Execute a console command (blocklist enforced)
`capture_viewport`	Take a screenshot of the active viewport
`get_output_log`	Fetch recent lines from the editor output log

unreal_assets (12 operations)

Operation	Description
`search`	Search the asset registry by name, type, or path fragment
`get_info`	Get full metadata for a specific asset by path
`list`	List assets in a given content directory
`dependencies`	Return all assets this asset depends on
`referencers`	Return all assets that reference this asset
`set_property`	Set a property on an asset via reflection
`save`	Save one or more assets to disk
`create_blueprint`	Create a new Blueprint class
`duplicate`	Duplicate an existing asset
`rename`	Rename an asset in-place
`delete`	Delete an asset (with reference check)
`move`	Move an asset to a new content path

unreal_blueprints (10 operations)

Operation	Description
`list`	List all Blueprints in a content directory
`inspect`	Get full variable and component list for a Blueprint
`get_graph`	Return all nodes and connections in a named graph
`get_events`	List all event nodes in a Blueprint
`create`	Create a new Blueprint (alias for unreal_assets create_blueprint)
`add_variable`	Add a typed variable to a Blueprint
`add_function`	Add a new function graph to a Blueprint
`add_node`	Add a node to a Blueprint graph
`connect_pins`	Connect two pins between nodes
`set_pin_value`	Set the default value of a node pin

unreal_animation (8 operations)

Operation	Description
`get_info`	Get metadata and state list for an Animation Blueprint
`create_state_machine`	Create a new state machine inside an Animation Blueprint
`add_state`	Add a state node to a state machine
`add_transition`	Add a transition between two states
`set_state_animation`	Assign a sequence or blend space to a state
`set_transition_duration`	Set the blend duration of a transition
`batch`	Execute multiple animation operations in one call
`validate_blueprint`	Compile and validate an Animation Blueprint

unreal_character (6 operations)

Operation	Description
`list_characters`	List all character Blueprint classes in the project
`get_character_info`	Get movement, mesh, and ability data for a character
`set_movement_params`	Tune CharacterMovementComponent parameters
`create_data_asset`	Create a character data asset from a template
`update_stats`	Update stat values on a character data asset
`create_stats_table`	Create a DataTable for character stats

unreal_input_materials (6 operations)

Operation	Description
`create_input_action`	Create an Enhanced Input action asset
`create_mapping_context`	Create an Input Mapping Context asset
`add_mapping`	Add an action mapping to a context with key bindings
`create_material_instance`	Create a Material Instance from a parent material
`set_material_parameters`	Set scalar, vector, and texture parameters on an instance
`get_material_info`	Get all parameters and their current values from a material

Tool Annotations

Each operation carries MCP tool annotations that inform clients how to safely schedule it. These are surfaced in tool discovery and affect parallel execution planning.

Annotation	Meaning	Examples
`readOnlyHint`	Does not modify editor state; safe to parallelize freely	get_level_actors, search, get_info, get_output_log
`destructiveHint`	May permanently delete or overwrite data	delete_actors, delete (assets)
`idempotentHint`	Calling twice produces the same result as once	set_property, move_actor, set_material_parameters
`openWorldHint`	May interact with external systems or network state	run_console_command, open_level

Warning: Operations tagged destructiveHint bypass the Recycle Bin on some platforms. Always verify asset paths before calling delete.

Parallel Execution Limits

The Unreal task queue processes a maximum of 4 concurrent MCP tasks. Exceeding this limit causes queued requests to time out.

Read-only operations (annotated readOnlyHint) are safe to run in parallel against any targets.
Modifying operations may be parallelized only when targeting different objects — never the same actor or asset from two concurrent calls.
Sequential-only operations: open_level, delete_actors, run_console_command. Always run these one at a time.
When coordinating subagents, cap at 3 subagents so the lead agent always retains one queue slot.

// All three are readOnlyHint — safe to fire simultaneously
parallel([
  { tool: "unreal_world",   operation: "get_level_actors", params: { class_filter: "PointLight" } },
  { tool: "unreal_assets",  operation: "search",           params: { query: "BP_Enemy" } },
  { tool: "unreal_character", operation: "list_characters", params: {} },
])

Licensing Tiers

All tiers include access to the full 97-operation surface. Restrictions apply to call rate limits and team seat counts, not to which operations are available.

Tier	Operations	Rate Limit	Seats
Free	All 97	60 req / min	1
Pro	All 97	600 req / min	5
Enterprise	All 97 + custom	Unlimited	Unlimited

Note: Enterprise tier includes priority queue access, dedicated support, and the ability to register custom MCP tools that appear alongside the built-in 97 operations in tool discovery.