Loomle MCP for Unreal MCP server

Loomle

Loomle is an agent-native Unreal Engine integration for reading and changing complex editor objects through SAL, the Structured Agent Language.

SAL turns Blueprint graphs, Widget trees, Class reflection, Assets, and other non-text UE state into compact, ordered text that both people and agents can read, copy, discuss, and patch. It stays faithful to UE: native paths, types, field names, values, palette actions, compiler diagnostics, and editor semantics remain native instead of being replaced by a parallel JSON model.

Why Loomle

Text code already gives agents precise search, references, diffs, and edits. Unreal assets do not. Loomle supplies that missing text workflow while keeping the editor and UE APIs as the source of truth.

entire graph.

• Compact SAL Object Text uses fewer tokens than large generic JSON payloads.
• Queries start with summaries and local views instead of downloading an

Widgets, and Blueprint objects safe to follow up without kind namespaces.

• Target-relative stable identity paths make returned Nodes, Pins, Graphs,

actually exposes instead of guessing constructors or fields.

• Palette and dynamic schema discovery let agents use capabilities that UE

mutation is applied.

• Dry runs share the real parse, resolve, validate, and plan path before any

they describe.

• Native compiler and object health diagnostics stay adjacent to the objects

Current 0.7 Interface

The standalone Client exposes eight MCP tools:

and Bridge health.

• status: inspect the Client version, update availability, and bound session

Unreal project.

• project: inspect project availability and bind this MCP session to one

a separate agent-specific installation.

• sal_query: execute one self-contained SAL Query Text.
• sal_patch: execute one ordered SAL Patch Text.
• sal_schema: discover the resident SAL guide and the active interface cards.
• agent_skill: discover and load MCP-managed Loomle workflow Skills without

open, focus, and close an exact Blueprint or Graph from canonical SAL Target Text.

• editor: observe the current Unreal interaction with empty arguments, or

capabilities not covered by a structured Loomle interface, and poll an execution only when the initial result supplies a continuation.

• python: run unrestricted Unreal Editor Python only as a fallback for

The current public SAL modules are Asset, Blueprint, Class, Graph, StateTree, and Widget. They cover Asset Registry discovery, Blueprint declarations and components, Class reflection and defaults, graph-local flow and mutation, StateTree hierarchy and bindings, Widget trees, factual reference queries, compilation, save, and editor context.

Example:

door = target {
  domain: blueprint,
  asset: "/Game/Blueprints/BP_Door.BP_Door"
}

query door
summary

Use salschema({}) for the active module index and salschema({ module: "graph" }) for one exact interface card. Supported exact reads and Palette Entries provide dynamic discovery with with schema; each interface card states the exact subjects that accept it.

Install

The latest stable Loomle release is available from GitHub Releases for Unreal Engine 5.7 and 5.8. Choose the package matching the installed engine version:

These stable filenames always resolve through the latest final GitHub Release. That release also retains immutable, versioned copies of both archives.

The Fab listing provides the current marketplace-approved Loomle build. GitHub Releases may be newer while a Fab update is under review.

The complete archive contains both native targets and their matching Clients:

Shortened. The full README is on GitHub.