git:20261101.d739dfc to git:20261101.c914bc4

---

name: unreal-official-mcp

description: >-

Enable, discover, and call Unreal Engine 5.8+ built-in Unreal MCP tools

through the DCC MCP gateway. Use when the user asks to set up, include,

compare, inspect, or use Epic's official MCP or Toolset Registry

capabilities. Not a replacement for DCC MCP on Unreal 4.18-5.7.

license: MIT

compatibility: DCC MCP Unreal 0.2+, optional Unreal Engine 5.8+ Unreal MCP plugin

allowed-tools: Read Bash

metadata:

dcc-mcp:

dcc: unreal

version: "0.2.0"

layer: integration

stage: runtime

search-hint: "enable setup bootstrap official epic unreal mcp model context protocol toolset registry bridge"

tags: [unreal, mcp, epic, toolset-registry, compatibility]

tools: tools.yaml

---

# Unreal Official MCP Bridge

Enable and bridge Epic's optional Unreal MCP into DCC MCP without

redistributing the Epic plugin. The engine plugin must be installed with the

engine; this skill can enable it for the current project and configure its

loopback HTTP endpoint.

## Workflow

1. Call `official_mcp_bridge` with `operation=status`.

2. If status is unavailable on Unreal Engine 5.8+, obtain explicit permission

to change project configuration, then call `prepare_official_mcp`. Enable

`NiagaraToolsets` only when the task needs Niagara authoring. Set

`include_pcg_toolset=true` only for a PCG task; it defaults to false.

3. When `restart_required` is true, restart the editor and verify the DCC MCP

instance before retrying `operation=status`. Do not claim success from the

configuration write alone.

4. Use `list_toolsets`, then `describe_toolset`, before calling an unfamiliar

tool. Preserve Epic's tool names and schemas.

5. Use `call_tool` with the selected toolset and arguments. Do not issue

overlapping mutating calls; Epic serializes tool invocations on the game

thread.

6. Fall back to the normal DCC MCP Unreal skills when the official endpoint is

unavailable or the running engine is older than 5.8.

The bridge accepts loopback HTTP endpoints only. Run it with `affinity:any`;

never block Unreal's game thread while making an HTTP request back into the

same editor process.

## PCG opt-in and safe setup

`prepare_official_mcp` checks actual installed descriptors, not an engine-version

guess. Epic's experimental `PCGToolset` descriptor is at

`Engine/Plugins/Experimental/Toolsets/PCGToolset/PCGToolset.uplugin` and declares

PCG descriptor at `Engine/Plugins/PCG/PCG.uplugin` (or the legacy

`Engine/Plugins/Experimental/PCG/PCG.uplugin` location). Missing, malformed,

ambiguous, unsupported, or explicitly project-disabled direct dependencies block

setup before any writes. It does not silently override a disabled dependency or

change unrelated project plugins. Newly encountered direct dependencies outside

the supported descriptor paths require manual review rather than an engine scan.

Both the project JSON and existing editor INI are validated before writing.

Setup preserves all existing INI bytes, including comments, repeated sections,

duplicate entries and array commands, appending only a final MCP settings block

when the four scalar settings need updating. Repeating setup makes no further

changes. Writes use atomic replacement; on a write failure, setup attempts to

restore the exact original file bytes or original absence. An incomplete

rollback is reported explicitly with the affected file paths. This is not a

crash-safe transaction across both files; keep normal project backups.

Successful setup means configuration was prepared, not that any plugin loaded

or PCG tool is available. `runtime_verified` remains false. Restart when requested,

then verify the live endpoint and discover its actual toolsets before authoring;

setup never starts a service, loads Unreal, or mutates a PCG graph.

References: [PCGToolset](https://dev.epicgames.com/documentation/unreal-engine/API/PluginIndex/PCGToolset),

[PCG](https://dev.epicgames.com/documentation/unreal-engine/API/PluginIndex/PCG), and

[Unreal plugins](https://dev.epicgames.com/documentation/en-us/unreal-engine/plugins-in-unreal-engine).

## Scripts

- `prepare_official_mcp`

- `official_mcp_bridge`