Tools Reference Overview

ClaudusBridge exposes Unreal Engine to an AI agent (or any MCP client) as a large catalog of callable tools, grouped into toolsets. There are 900+ tools across ~65 toolsets, drawn from two sources:

1. Engine-reflected toolsets — generated automatically from Unreal's reflection system. Any UFUNCTION marked meta=(AICallable) and grouped by a UToolsetDefinition becomes a tool. These are surfaced through Unreal's ToolsetRegistry / AllToolsets engine plugins and cover most editor domains (Actors/World, Blueprints, Materials, Niagara, UMG/Widgets, Sequencer, Assets, Levels, Textures, and many more).
2. Native plugin toolsets — fourteen toolsets implemented directly in ClaudusBridge for capabilities the engine does not provide out of the box: Multi-User, Asset, Level, Image, Chess, MaterialGraph, Reflection, Niagara (script graphs), NiagaraSystem, Orchestration, AnimBlueprint, Simulation, BlueprintComponent, and BlueprintToCpp.
3. User-authored ToolLibrary Blueprints — your own tools, added by subclassing UClaudusBridgeToolLibrary (see the ToolLibrary authoring guide). These auto-register alongside everything else.

All of these are served by the MCP HTTP server at http://127.0.0.1:3000/mcp (JSON-RPC 2.0 over Streamable HTTP).

Toolset categories

The catalog spans most of the editor. The table below lists representative categories — the live set depends on which engine plugins are enabled in your project.

Category	What it drives	Source
Actors / World	Spawn, transform, delete, select actors; query the level; components	Engine-reflected
Blueprints	Create Blueprints, add variables/functions/components, set defaults, compile	Engine-reflected
Materials	Create materials and instances, edit graphs, set parameters	Engine-reflected
UMG / Widgets	Build Widget Blueprints, add and lay out widgets, bind properties	Engine-reflected
Niagara	Create and configure Niagara systems and emitters	Engine-reflected
Sequencer	Create level sequences, add tracks/keys, drive cinematics	Engine-reflected
Assets	Import, reference, query, and organize Content Browser assets	Engine-reflected
Levels	Open/stream levels, manage actors per level	Engine-reflected
Textures	Create and edit textures and render targets	Engine-reflected
Multi-User	Join/host Concert sessions, presence avatars, launch a headless agent	Native (ClaudusBridge)
Asset	Create ToolLibraries/AgentSkills, find/duplicate/save assets, dependencies	Native (ClaudusBridge)
Level	Save current level / all dirty packages, persist session changes, folders, open level	Native (ClaudusBridge)
Image	Save images, export textures to disk, show a texture	Native (ClaudusBridge)
Chess	Build a 3D chess board, move/spawn pieces, autonomous play, agent camera	Native (ClaudusBridge)
Orchestration	Async job queue, agent sessions, advisory asset locks, editor busy-state — the multi-agent workbench	Native (ClaudusBridge)
MaterialGraph	Read a fully resolved material graph, rename/split parameters, author Custom HLSL nodes, connect/delete expressions by index	Native (ClaudusBridge)
Niagara (script graphs)	Describe/author Niagara module & function script graphs: Custom HLSL, inputs, includes, wiring, referencers	Native (ClaudusBridge)
NiagaraSystem	System-level Niagara: user parameters from simple specs, DI bindings, non-blocking compile state, dead-parameter scan	Native (ClaudusBridge)
Reflection	Invoke any reflected UFUNCTION on any UObject by name with JSON-marshalled arguments	Native (ClaudusBridge)
AnimBlueprint / Simulation / BlueprintComponent / BlueprintToCpp	AnimBP inspection, headless game-feel verification, live SCS component edits, Blueprint→C++ scaffolding	Native (ClaudusBridge)

The native toolsets ship these AICallable tools:

• Multi-User: GetConnectionStatus, ListServers, ListSessions, CreateSession, JoinSession, LeaveSession, SetLocalIdentity, EnablePresence, ListParticipants, LaunchAgentEditor, StopAgentEditor.
• Asset: CreateToolLibrary, CreateAgentSkill, FindAssets, GetAssetInfo, MakeUniqueAssetName, DuplicateAsset, SaveAsset, GetAssetDependencies.
• Level: SaveCurrentLevel, SaveCurrentLevelAs, SaveAllDirtyPackages, PersistSessionChanges, CreateFolder, OpenLevel.
• Image: SaveImage, ExportTexture, ShowTexture.
• Chess: SetupChessGame, GetBoardState, MovePiece, RemovePiece, SpawnPiece, ClearChessGame, DetectMove, NormalizeChessPieces, StartAutoPlay, StopAutoPlay, plus agent-camera tools GetAgentViewPose, AgentLookFrom, LookAtParticipant.
• Orchestration: RunToolAsync, GetJobStatus, GetJobResult, ListJobs, CancelJob, RegisterAgentSession, ListAgentSessions, EndAgentSession, AcquireAssetLock, ReleaseAssetLock, ListAssetLocks, GetEditorBusyState. See the Multi-Agent Orchestration guide.
• NiagaraSystem: ListNiagaraEmitters, GetNiagaraUserParameters, AddNiagaraUserParameters, RemoveNiagaraUserParameters, BindNiagaraDataInterfaceInput, GetNiagaraCompileStateFast, RequestNiagaraCompile, WaitNiagaraCompile, FindUnreferencedNiagaraUserParameters.
• Niagara (script graphs): DescribeNiagaraScript, ListNiagaraReferencers, SetNiagaraCustomHlsl, SetNiagaraCustomHlslIncludes, WireNiagaraPins, SetNiagaraFunctionOutputs, CreateNiagaraScript, AddNiagaraCustomHlslNode, AddNiagaraValueInput, AddNiagaraModuleInput, AddNiagaraDataInterfaceInput, AddNiagaraDataInterfaceFunctionNode, RemoveNiagaraNode.
• MaterialGraph: DescribeMaterialGraph, SetParameterByIndex, ConfigureCustomNode, ConnectMaterialExpressions, DeleteMaterialExpression.

Tool-search discovery (default mode)

With 900+ tools, registering every one as a native MCP tool would overwhelm most clients. By default ClaudusBridge runs in tool-search mode (bEnableToolSearch = true), where tools/list returns only three meta-tools. The agent discovers everything else on demand through them:

Meta-tool	Purpose
list_toolsets	List all available toolsets (names + short descriptions).
describe_toolset	Get the tools in one toolset, with parameters and docs.
call_tool	Invoke any tool by name with a JSON arguments object.

A typical discovery flow:

// 1. See what toolsets exist
{ "method": "tools/call", "params": { "name": "list_toolsets", "arguments": {} } }

// 2. Drill into one
{ "method": "tools/call", "params": {
    "name": "describe_toolset",
    "arguments": { "toolset": "Materials" } } }

// 3. Call a tool from it
{ "method": "tools/call", "params": {
    "name": "call_tool",
    "arguments": {
      "tool": "CreateMaterial",
      "args": { "path": "/Game/Materials/M_Demo" }
    } } }

Eager mode

If you prefer every tool registered natively (so MCP clients see the full list in tools/list), set bEnableToolSearch = false in Project Settings → ClaudusBridge. This is heavier on the client but lets clients that lack their own discovery layer browse the whole catalog directly. Tool-search mode is recommended for most agents.

Naming conventions

• Native plugin tools use plain PascalCase verbs scoped by their category in source (ClaudusBridge|MultiUser, ClaudusBridge|Asset, etc.), e.g. JoinSession, FindAssets, SaveCurrentLevel, MovePiece.
• Engine-reflected tools inherit the names of the underlying UFUNCTIONs, typically Verb + Noun (e.g. SpawnActor, CreateMaterial, AddWidget). Parameter names match the function's reflected parameters.
• Meta-tools are lower_snake_case (list_toolsets, describe_toolset, call_tool).

When in doubt, call describe_toolset — it returns the authoritative tool names and parameter schemas for the running editor and enabled plugins.

How to explore tools

• From the embedded agent: just ask it. The agent in the ClaudusCode terminal already knows to call list_toolsets / describe_toolset and will pick the right tool for your request.
• From an external MCP client (Claude, Cursor, Windsurf): point it at http://127.0.0.1:3000/mcp, then call the three meta-tools to browse and invoke.
• Health check: GET http://127.0.0.1:3000/health returns the server status, port, and MCP path so you can confirm the bridge is live before driving it.
• Port override: launch the editor with -ClaudusBridgePort=N (useful when running multiple editor instances, e.g. an agent and a human in Multi-User).

The domain guides in this section walk through common workflows for Actors/World, Blueprints, Materials, and UMG widgets.