unreal_world

The unreal_world tool covers everything related to actors, levels, console commands, and the editor viewport. It exposes 9 operations for spawning, moving, deleting, and inspecting actors, plus utilities for running console commands and capturing screenshots.

Operations at a Glance

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

Warning: open_level, delete_actors, and run_console_command must always be called sequentially — never in parallel with other operations.

spawn_actor

Spawns an actor of any registered class into the current level. The actor appears immediately in the editor viewport.

Parameters

Parameter	Type	Required	Description
`class_path`	string	yes	Full UE class path, e.g. `/Script/Engine.PointLight`
`name`	string	no	Display name for the new actor. Auto-generated if omitted.
`location`	object	no	`{ x, y, z }` in world units. Defaults to origin.
`rotation`	object	no	`{ pitch, yaw, roll }` in degrees.
`scale`	object	no	`{ x, y, z }` scale multiplier. Defaults to `1,1,1`.

{
  "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": "spawn_actor",
  "params": {
    "class_path": "/Script/Engine.StaticMeshActor",
    "name": "Boulder_01",
    "location": { "x": 0, "y": 500, "z": 0 },
    "scale": { "x": 2.0, "y": 2.0, "z": 2.0 }
  }
}

Notes

class_path must be a fully qualified UE class path starting with /Script/ for engine classes or /Game/ for Blueprint classes.
Blueprint actors use the path format /Game/Blueprints/BP_MyActor.BP_MyActor_C.
The spawned actor's name must be unique within the level. If a name collision occurs, a numeric suffix is appended automatically.

move_actor

Moves, rotates, or scales an existing actor. You can set any combination of transform components in a single call.

Parameters

Parameter	Type	Required	Description
`name`	string	yes	Exact name of the actor to move
`location`	object	no	New `{ x, y, z }` world position
`rotation`	object	no	New `{ pitch, yaw, roll }` in degrees
`scale`	object	no	New `{ x, y, z }` scale

{
  "operation": "move_actor",
  "params": {
    "name": "FillLight_01",
    "location": { "x": 400, "y": -200, "z": 350 },
    "rotation": { "pitch": -45, "yaw": 90, "roll": 0 }
  }
}

Note: move_actor is idempotent — calling it twice with the same parameters produces the same result. It is safe to parallelize across different actor names.

delete_actors

Deletes one or more actors from the current level. Accepts a name list, a class filter, or both.

Parameters

Parameter	Type	Required	Description
`names`	string[]	no	Array of actor names to delete
`class_filter`	string	no	Delete all actors of this class (e.g. `PointLight`)
`confirm`	boolean	no	Must be `true` to execute. Safety interlock.

{
  "operation": "delete_actors",
  "params": {
    "names": ["TempLight_01", "TempLight_02", "TempLight_03"],
    "confirm": true
  }
}

{
  "operation": "delete_actors",
  "params": {
    "class_filter": "PointLight",
    "confirm": true
  }
}

Warning: delete_actors is tagged destructiveHint. Deleted actors cannot be recovered through gengine — use Ctrl+Z in the editor immediately if you need to undo. The operation is capped at 200 actors per call to prevent accidental mass deletion.

set_property

Sets any actor property using Unreal Engine's reflection system. This works on any UPROPERTY-exposed field without requiring a custom tool.

Parameters

Parameter	Type	Required	Description
`actor`	string	yes	Name of the target actor
`property`	string	yes	Property name as it appears in UE reflection (case-sensitive)
`value`	any	yes	New value. Type must match the property type.
`component`	string	no	If set, targets a named component on the actor instead of the actor itself

{
  "operation": "set_property",
  "params": {
    "actor": "FillLight_01",
    "property": "Intensity",
    "value": 5000.0
  }
}

{
  "operation": "set_property",
  "params": {
    "actor": "BP_Enemy_01",
    "property": "MaxHealth",
    "value": 250
  }
}

{
  "operation": "set_property",
  "params": {
    "actor": "PlayerStart_0",
    "component": "ArrowComponent",
    "property": "bHiddenInGame",
    "value": true
  }
}

Supported Value Types

Numeric: float, int32, int64 — pass as JSON numbers
Boolean: pass as true / false
String / FName / FText: pass as JSON string
Struct (FVector, FRotator, FLinearColor): pass as { "x": 0, "y": 0, "z": 0 } or { "r": 1, "g": 0, "b": 0, "a": 1 }
Object reference: pass the full asset path string

get_level_actors

Returns a list of all actors in the currently open level, with metadata for each.

Parameters

Parameter	Type	Required	Description
`class_filter`	string	no	Only return actors of this class (partial match)
`name_filter`	string	no	Only return actors whose name contains this string
`include_components`	boolean	no	If true, include component list for each actor

{
  "operation": "get_level_actors",
  "params": {
    "class_filter": "PointLight"
  }
}

{
  "operation": "get_level_actors",
  "params": {
    "name_filter": "BP_Enemy",
    "include_components": true
  }
}

Response Shape

{
  "actors": [
    {
      "name": "FillLight_01",
      "class": "PointLight",
      "location": { "x": 200, "y": -100, "z": 300 },
      "rotation": { "pitch": 0, "yaw": 0, "roll": 0 },
      "scale": { "x": 1, "y": 1, "z": 1 },
      "tags": [],
      "components": ["LightComponent0", "ArrowComponent"]
    }
  ],
  "total": 1
}

Note: get_level_actors is tagged readOnlyHint — safe to run in parallel with other read-only operations.

open_level

Opens, creates, saves, or lists levels. This is a high-impact operation that affects the entire editor session.

Parameters

Parameter	Type	Required	Description
`action`	string	yes	One of: `open`, `create`, `save`, `list`
`path`	string	no	Level asset path (required for `open` and `create`)
`name`	string	no	New level name (used with `create`)

{
  "operation": "open_level",
  "params": {
    "action": "open",
    "path": "/Game/Maps/L01_Dungeon"
  }
}

{
  "operation": "open_level",
  "params": {
    "action": "create",
    "path": "/Game/Maps/",
    "name": "L02_Village"
  }
}

{
  "operation": "open_level",
  "params": {
    "action": "list"
  }
}

Warning: open_level is tagged openWorldHint and must always run sequentially. Opening a level while other operations are in flight can cause state corruption or crashes.

run_console_command

Executes a console command in the editor. A blocklist prevents dangerous commands from running.

Parameters

Parameter	Type	Required	Description
`command`	string	yes	The console command string to execute

{
  "operation": "run_console_command",
  "params": {
    "command": "r.SetRes 1920x1080"
  }
}

{
  "operation": "run_console_command",
  "params": {
    "command": "stat fps"
  }
}

Blocklisted Commands

The following command prefixes are always blocked regardless of safety tier:

quit, exit — would close the editor
RestartEditor — editor restart
open — level loading (use open_level instead)
disconnect, reconnect — network state
exec — arbitrary script execution
obj savepackage — raw package writes

Warning: run_console_command is tagged openWorldHint. Always run sequentially. Never parallelize with level-loading or actor-deletion operations.

capture_viewport

Takes a screenshot of the active editor viewport and saves it to disk.

Parameters

Parameter	Type	Required	Description
`resolution`	string	no	Output resolution, e.g. `"1920x1080"`. Defaults to current viewport size.
`filename`	string	no	Output filename without extension. Defaults to auto-generated timestamp.
`show_ui`	boolean	no	If true, includes editor UI overlays. Defaults to false.

{
  "operation": "capture_viewport",
  "params": {
    "resolution": "1920x1080",
    "filename": "lighting_test_01"
  }
}

Response

{
  "path": "C:/Users/.../Saved/Screenshots/lighting_test_01.png",
  "resolution": "1920x1080",
  "size_bytes": 2457600
}

Note: capture_viewport is tagged readOnlyHint — it does not modify editor state. Safe to parallelize for capturing multiple viewports in sequence.

get_output_log

Fetches recent lines from the Unreal Editor output log. Useful for reading compile errors, warnings, or custom log messages after an operation.

Parameters

Parameter	Type	Required	Description
`lines`	integer	no	Number of recent lines to return. Default: 100. Max: 1000.
`filter`	string	no	Only return lines containing this string (case-insensitive)
`category`	string	no	Filter by log category, e.g. `LogBlueprint`, `LogTemp`

{
  "operation": "get_output_log",
  "params": {
    "lines": 50,
    "category": "LogBlueprint"
  }
}

{
  "operation": "get_output_log",
  "params": {
    "lines": 200,
    "filter": "Error"
  }
}

Response

{
  "lines": [
    "[2025.01.15-14:32:07] LogBlueprint: Error: [BP_Enemy] Variable 'AggroRange' not found",
    "[2025.01.15-14:32:07] LogBlueprint: Warning: [BP_Enemy] Compile completed with 1 error"
  ],
  "total_returned": 2,
  "total_available": 4821
}

Common Patterns

Three-Point Lighting Rig

Spawn a key light, fill light, and rim light in one parallel batch, then adjust their intensities.

// Read-only operations are parallel-safe
// But spawn_actor modifies state — only parallelize on DIFFERENT actors
sequential([
  spawn_actor({ class_path: "/Script/Engine.DirectionalLight", name: "KeyLight", location: {x:500, y:0, z:400}, rotation: {pitch:-45, yaw:0, roll:0} }),
  spawn_actor({ class_path: "/Script/Engine.PointLight", name: "FillLight", location: {x:-300, y:200, z:200} }),
  spawn_actor({ class_path: "/Script/Engine.SpotLight", name: "RimLight", location: {x:0, y:-400, z:300} }),
])
// Now parallelize property sets on different actors
parallel([
  set_property({ actor: "KeyLight", property: "Intensity", value: 10.0 }),
  set_property({ actor: "FillLight", property: "Intensity", value: 3000.0 }),
  set_property({ actor: "RimLight", property: "Intensity", value: 5000.0 }),
])

Inspect Then Modify

Use get_level_actors to discover actors before modifying them.

// 1. Read — safe to run first
const result = await get_level_actors({ class_filter: "PointLight" })
// 2. Modify each discovered actor
for (const actor of result.actors) {
  await set_property({ actor: actor.name, property: "AttenuationRadius", value: 800 })
}

Batch Viewport Captures

Capture screenshots at multiple resolutions. capture_viewport is read-only and parallel-safe.

parallel([
  capture_viewport({ resolution: "3840x2160", filename: "hero_4k" }),
  capture_viewport({ resolution: "1920x1080", filename: "hero_1080p" }),
  capture_viewport({ resolution: "1280x720",  filename: "hero_720p" }),
])