asset-management

🧠 Brains complement: IF an unreal-engine-skills-manager tool (external MCP) exists in this session, call it with {action: "load", skill: "asset-management"} for UE domain knowledge on this topic — correct APIs, architecture, best practices — and treat it as the rubric for any review / "best practices" question. If no such tool is available (e.g. running under Claude Code or Codex without that MCP), skip this line entirely and proceed with this skill alone — do NOT attempt the call.

Asset Discovery & Management Skill

🔀 Engine owns general asset ops now. In the Unreal 5.8 consolidation, searching, loading, saving, moving, renaming, duplicating, and deleting assets moved to Unreal's native AssetTools toolset (reach it via call_tool; run describe_toolset for its actions) — or you can drive unreal.EditorAssetLibrary / unreal.AssetRegistryHelpers directly from execute_python_code. The old manage_asset MCP tool is GONE. VibeUE's AssetDiscoveryService was trimmed to only the crash-safe delta the engine doesn't provide:

Kept on AssetDiscoveryService	Purpose
import_asset(src, dest_folder, name) → (path, err)	Crash-safe image import (folder + name)
import_texture(src, dest_asset_path)	Crash-safe image import (full asset path)
export_texture(asset_path, file_path)	Export a texture to disk
get_primary_content_browser_selection() → AssetData or None	Primary Content Browser selection
is_asset_open(asset_path) → bool	Whether an asset is open in an editor

Everything else below (search_assets, list_assets_in_path, move_asset, duplicate_asset, delete_asset, save_asset, get_open_assets, get_asset_referencers, find_asset_by_path, asset_exists, …) was removed from AssetDiscoveryService — use the engine AssetTools toolset or EditorAssetLibrary / the Asset Registry.

Data Assets & Data Tables — no dedicated VibeUE service (issues #451, #452)

There is no DataAssetService / DataTableService. Drive them natively:

import unreal

# --- Data Assets (UPrimaryDataAsset / UDataAsset subclasses) ---
# Create: engine DataAssetTools toolset via call_tool (describe_toolset for the action), OR a factory.
da = unreal.load_asset("/Game/Data/DA_Thing")
val = da.get_editor_property("MyField")          # read
da.set_editor_property("MyField", 42)            # write — works for any UPROPERTY
unreal.EditorAssetLibrary.save_loaded_asset(da)

# --- Data Tables ---
dt = unreal.load_asset("/Game/Data/DT_Items")
names = unreal.DataTableFunctionLibrary.get_data_table_row_names(dt)   # row keys
# Read/write rows with the editor DataTable API:
#   unreal.DataTableFunctionLibrary.evaluate_curve_table_row(...) / get_data_table_column_as_string(dt, "Col")
# Engine DataTableTools (call_tool) covers add/remove/get rows + import/export CSV/JSON.

⚠️ Data Table gotchas (verified, #452): the row key ("Name") is reported as a column by some schema readers — it is the row id, not a data field. Writing a row with the wrong value type can be silently coerced — read the row back to confirm. There is no clear_rows; remove rows individually (engine DataTableTools) or re-import an empty CSV. An empty GameplayTag field serializes as "None".

Critical Rules

⚠️ Out-Params Become Return Values in Python — Never Pass an AssetData Argument

get_primary_content_browser_selection is shaped like bool Func(FAssetData& Out) in C++ and is exposed to Python as () -> AssetData or None. Passing an AssetData argument raises TypeError.

# WRONG - TypeError: takes no arguments (1 given)
asset = unreal.AssetData()
unreal.AssetDiscoveryService.get_primary_content_browser_selection(asset)

# CORRECT - call with no out-arg, check the return for None
asset = unreal.AssetDiscoveryService.get_primary_content_browser_selection()
if asset:
    print(asset.asset_name)

🔀 Where each operation lives now

🔀 ALL open assets / ALL selections / open an asset — use Epic's EditorAppToolset

VibeUE covers the single/primary queries above; the list-all and open operations live on Epic's native EditorToolset.EditorAppToolset (call via call_tool; returns {"returnValue": [...]} of package-path strings). These are NOT Python-bound — they only work through call_tool:

# "Show me all open Blueprints" = Epic GetOpenAssets + a type filter
opens = call_tool("GetOpenAssets", "EditorToolset.EditorAppToolset")["returnValue"]
bps = [p for p in opens if isinstance(unreal.load_asset(p), unreal.Blueprint)]

# "Open the selected asset" = VibeUE primary-selection + Epic OpenEditorForAsset
sel = unreal.AssetDiscoveryService.get_primary_content_browser_selection()
if sel:
    call_tool("OpenEditorForAsset", "EditorToolset.EditorAppToolset",
              {"assetPath": str(sel.package_name)})

🚨 Never list broad paths — a /Game listing can return 30,000+ assets

Listing every asset under /Game returns tens of thousands of entries and floods the conversation. Whether you go through the engine AssetTools toolset or EditorAssetLibrary.list_assets, always narrow first:

• Filter by a specific subfolder (e.g. /Game/Blueprints/HUD), and by class where supported.
• If you only need a count or sample, slice in Python before printing — never print the full array.

⚠️ EditorAssetLibrary Save Methods

There is no save_dirty_assets (AttributeError). The real options: unreal.EditorAssetLibrary.save_asset(path), save_directory(dir), save_loaded_asset(obj), save_loaded_assets([objs]). To save everything dirty, iterate or use the engine AssetTools toolset's save action.

⚠️ EditorAssetLibrary.list_assets Has No Class Filter

unreal.EditorAssetLibrary.list_assets(directory_path, recursive=True, include_folder=False) returns path strings only — there is no asset_class_names or any other class-filter kwarg (TypeError: invalid keyword argument). To list assets of one type, either filter the returned paths in Python (load each and check its class), or query the Asset Registry with a class filter via unreal.AssetRegistryHelpers.get_asset_registry().get_assets(...).

⚠️ UE 5.8 AssetData Property Names

get_primary_content_browser_selection() returns an AssetData. Read it with:

AssetData has no object_path attribute (AttributeError). Build it from package_name + asset_name, or just use str(asset.package_name).

⚠️ Importing Image Files From Disk — Stay on AssetDiscoveryService

To bring an image file from disk into the Content Browser, use AssetDiscoveryService.import_asset (or import_texture). Do NOT call unreal.AssetToolsHelpers...import_asset_tasks or ImportAssets from execute_python_code — those pump the game-thread task graph and trip a RecursionGuard assertion that crashes the editor when run from inside a tool call. AssetDiscoveryService uses the texture factory's direct binary path, which is safe.

import unreal

# Crash-safe import (disk → Content Browser). Returns (asset_path, error); path is "" on failure.
path, err = unreal.AssetDiscoveryService.import_asset(
    "C:/Images/rocks.jpg", "/Game/UI/Textures", "T_Rocks")
print(path or err)

# WRONG — crashes the editor (TaskGraph RecursionGuard assertion)
# tasks = [unreal.AssetImportTask()]; unreal.AssetToolsHelpers.get_asset_tools().import_asset_tasks(tasks)

Supported image formats: png, jpg, jpeg, bmp, tga, dds, exr, hdr, tiff, tif, psd, pcx.

Need a source image to import? Editor screenshots live under the project's Saved/Screenshots (and Saved/VibeUE/Screenshots):

import os, unreal
shots = os.path.join(unreal.Paths.project_saved_dir(), "Screenshots")
print(os.listdir(shots) if os.path.isdir(shots) else "no screenshots yet")

⚠️ Asset Paths Must Be Content Browser Paths

Use /Game/... paths, not file system paths, everywhere except the disk side of import/export.

# WRONG - file system path
unreal.EditorAssetLibrary.does_asset_exist("C:/Projects/Content/BP_Player.uasset")

# CORRECT - content browser path
unreal.EditorAssetLibrary.does_asset_exist("/Game/Blueprints/BP_Player")

⚠️ Never Emulate Move/Rename with Duplicate + Delete

Duplicating creates a new asset identity. References stay pointed at the original, so deleting the original after a duplicate can break those references. Use a real move/rename (which fixes up references) instead:

import unreal

# EditorAssetLibrary.rename_asset performs a move + reference fixup
unreal.EditorAssetLibrary.rename_asset(
    "/Game/StateTree/STT_Rotate",
    "/Game/StateTree/Tasks/STT_Rotate")

(The engine AssetTools toolset exposes an equivalent move/rename action via call_tool.)

Creating Widget Blueprints

Use the engine's WidgetBlueprintFactory — a plain BlueprintFactory with a UserWidget parent creates a regular Blueprint, not a WidgetBlueprint (the removed BlueprintService.create_blueprint used to pick the UMG factory automatically):

factory = unreal.WidgetBlueprintFactory()
factory.set_editor_property("ParentClass", unreal.UserWidget)
wbp = unreal.AssetToolsHelpers.get_asset_tools().create_asset("WBP_Menu", "/Game/UI", None, factory)

For designing the widget afterwards (hierarchy, slots, bindings), load the umg-widgets skill.

---

Workflows

Search Pattern

Searching is an engine AssetTools job (via call_tool) — or query the Asset Registry directly:

import unreal

ar = unreal.AssetRegistryHelpers.get_asset_registry()

# All Blueprints under /Game (recursive). Use a class filter and a narrow path to avoid huge results.
f = unreal.ARFilter(
    package_paths=["/Game/Blueprints"],
    class_paths=[unreal.TopLevelAssetPath("/Script/Engine", "Blueprint")],
    recursive_paths=True)
for a in ar.get_assets(f)[:25]:
    print(f"{a.asset_name}: {a.package_path}")

Check Exists Pattern

import unreal

if unreal.EditorAssetLibrary.does_asset_exist("/Game/BP_Player"):
    print("Found")
else:
    print("Not found - create it")

Duplicate Pattern

import unreal

dup = unreal.EditorAssetLibrary.duplicate_asset("/Game/BP_Enemy", "/Game/BP_EnemyBoss")
if dup:
    print("Duplicated")

Move / Rename Pattern

import unreal

ok = unreal.EditorAssetLibrary.rename_asset(
    "/Game/StateTree/STT_Rotate",
    "/Game/StateTree/Tasks/STT_Rotate")
print("Moved (references fixed up)" if ok else "Move failed")

Save Pattern

import unreal

# Save a specific asset
unreal.EditorAssetLibrary.save_asset("/Game/BP_Player")

# Save a whole directory of dirty assets
unreal.EditorAssetLibrary.save_directory("/Game/Blueprints")

Check References Before Delete

Asset Registry referencer queries return package-name strings, not AssetData.

import unreal

ar = unreal.AssetRegistryHelpers.get_asset_registry()
refs = ar.get_referencers(
    "/Game/SM_Weapon",
    unreal.AssetRegistryDependencyOptions(include_hard_package_references=True))
if not refs:
    unreal.EditorAssetLibrary.delete_asset("/Game/SM_Weapon")
else:
    for ref in refs:          # ref is a package name, e.g. "/Game/Blueprints/BP_Player"
        print(f"In use by: {ref}")

⚠️ Deleting levels: delete_asset on a recently-loaded .umap can return True (asset gone from the registry) yet leave the package file on disk, so delete_directory on its folder then fails. After deleting level assets, verify the Content/... folder on disk and remove leftover .umap files manually.

Import / Export Textures (VibeUE — crash-safe)

import unreal

# Import (disk → Content Browser). Returns (asset_path, error); asset_path is "" on failure.
# Pass a destination FOLDER + optional asset name.
path, err = unreal.AssetDiscoveryService.import_asset(
    "C:/Textures/logo.png", "/Game/Textures", "T_Logo")
print(path or err)

# import_texture(src, dest_asset_path) takes a full asset path and uses the same crash-safe importer:
unreal.AssetDiscoveryService.import_texture("C:/Textures/logo.png", "/Game/Textures/T_Logo")

# Export (project → file system)
unreal.AssetDiscoveryService.export_texture("/Game/Textures/T_Logo", "C:/Exports/logo.png")

Editor State & Content Browser (VibeUE)

import unreal

# Is a specific asset open in an editor?
if unreal.AssetDiscoveryService.is_asset_open("/Game/BP_Player"):
    print("BP_Player is open")

# Primary Content Browser selection — NO out-arg, returns AssetData or None
asset = unreal.AssetDiscoveryService.get_primary_content_browser_selection()
if asset:
    print(f"Selected: {asset.asset_name} at {asset.package_path}")
    # Open it via the AssetEditorSubsystem (engine), loading the object first:
    obj = unreal.EditorAssetLibrary.load_asset(str(asset.package_name))
    unreal.get_editor_subsystem(unreal.AssetEditorSubsystem).open_editor_for_assets([obj])
else:
    print("Nothing selected")

For the full multi-selection set, open-editor lists, and search, use the engine AssetTools / AssetEditorSubsystem toolsets via call_tool.

Inspect the Selection's Class

asset.asset_class_path is a TopLevelAssetPath struct, not a string — compare its asset_name:

import unreal

asset = unreal.AssetDiscoveryService.get_primary_content_browser_selection()
if asset and str(asset.asset_class_path.asset_name) == "Blueprint":
    print(f"{asset.asset_name} is a Blueprint")

Create Non-Standard Asset Types (Factory Pattern)

Assets not covered by a VibeUE service (e.g., LandscapeGrassType) require AssetToolsHelpers + a factory. (The create_asset factory path is safe — only the import task-graph APIs crash.)

import unreal

asset_tools = unreal.AssetToolsHelpers.get_asset_tools()

factory = unreal.LandscapeGrassTypeFactory()
lgt = asset_tools.create_asset("LGT_MyGrass", "/Game/Landscape", unreal.LandscapeGrassType, factory)

# Set properties via set_editor_property, then save
unreal.EditorAssetLibrary.save_asset("/Game/Landscape/LGT_MyGrass")

Tip: Use discover_python_module("unreal", name_filter="Factory") to find available factories.

Common Asset Class Names for Filtering

• Blueprint, WidgetBlueprint
• Texture2D, Material, MaterialInstanceConstant
• StaticMesh, SkeletalMesh
• DataTable, PrimaryDataAsset
• LandscapeGrassType, LandscapeLayerInfoObject

Class names must match UE class names exactly (e.g., LandscapeGrassType, not GrassType). When a typed Asset Registry query unexpectedly returns 0, retry without the class filter and inspect each result's asset_class_path.asset_name to learn the real class name.

Sample scripts (run via execute_python_code)

• scripts/find_and_save.txt — find an asset (Asset Registry / EditorAssetLibrary) and duplicate + save it.