Unreal Engine MCP

Italiano

An MCP server that lets an AI agent drive Unreal Engine 5: create projects, import assets, build levels and Blueprints, configure replication, compile C++, run Play In Editor and package the game.

No C++ plugin to compile. It uses two plugins that already ship with the engine — Python Editor Script Plugin and Remote Control API — and talks to the editor over local HTTP.

                    ┌─ LOCAL layer  ── processes + public HTTP
                    │    UnrealEditor.exe, UnrealBuildTool, RunUAT, asset downloads
Agent ──stdio──▶ MCP │
                    └─ EDITOR layer ── HTTP :30010 (Remote Control API)
                         └─ ExecutePythonCommandEx → running editor

The local layer exists because the Remote Control API only works against an editor that is already running: creating a project, launching it, compiling and packaging all have to happen at the process level.

• 162 tools and 5 resources — full reference

• 435 tests, none of which need Unreal installed

• Unreal automation notes — the API traps found the hard way

Requirements

• Unreal Engine 5.0 or newer (developed and tested against 5.8 — see version compatibility)

• Python 3.10+

• Windows, Linux or macOS. Development happens on Windows, which is where the local layer is exercised most; the Linux and macOS paths (Build.sh, RunUAT.sh, pgrep) are implemented and covered by CI, but less battle-tested. The editor layer is platform-neutral.

Unreal version compatibility

The server detects what the running engine supports at startup of each call — ue_status reports it under capabilities — and fails with an explicit message instead of a cryptic Python error when a feature is missing:

Custom engine builds are fine: detection is based on the actual Python API surface, not on the version number.

Related MCP server: Hayba

Install

pip install unreal-engine-mcp

Or run it without installing anything, if you have uv:

uvx unreal-engine-mcp

Or from source, to hack on it:

git clone https://github.com/FFZackFair92/unreal-engine-mcp.git
cd unreal-engine-mcp
pip install -e .

Connect it to your client

The server speaks standard MCP over stdio, so any MCP-capable client works — Claude, Cursor, VS Code, Windsurf, OpenAI Codex, custom agents. The command is always the same; only where the config lives differs.

Claude Desktop / Cowork

Settings ▸ Developer ▸ Edit Config, then add to mcpServers:

{
  "mcpServers": {
    "unreal-mcp": {
      "command": "python",
      "args": ["-m", "unreal_mcp.server"],
      "env": { "UE_MCP_PORT": "30010" }
    }
  }
}

Claude Code

claude mcp add unreal-mcp -- python -m unreal_mcp.server

Cursor

~/.cursor/mcp.json (global) or .cursor/mcp.json in the project — same JSON shape as Claude Desktop (mcpServers root key).

VS Code (Copilot agent mode)

.vscode/mcp.json — note the root key is servers here:

{
  "servers": {
    "unreal-mcp": { "type": "stdio", "command": "python", "args": ["-m", "unreal_mcp.server"] }
  }
}

Windsurf

~/.codeium/windsurf/mcp_config.json — same mcpServers shape as Claude Desktop.

OpenAI Codex CLI

~/.codex/config.toml:

[mcp_servers.unreal-mcp]
command = "python"
args = ["-m", "unreal_mcp.server"]

OpenAI Agents SDK (custom agents)

from agents.mcp import MCPServerStdio

unreal = MCPServerStdio(params={"command": "python", "args": ["-m", "unreal_mcp.server"]})

Restart the client completely after editing its config. In every case python must be the interpreter where you ran pip install -e . — use an absolute path if in doubt.

Note: ChatGPT's connector UI only accepts remote MCP servers. This server is stdio/local by design (it drives processes on your machine), so use it from clients with stdio support — the ones above — or wrap it with an MCP proxy if you really need HTTP.

Set up the Unreal side

Starter project — zero setup, zero builds

Copy StarterProject/ wherever you like and open the .uproject with any UE 5.0+: plugins enabled, security config in place, web server auto-started. Being Blueprint-only with engine plugins, there is nothing to compile — unlike starters that bundle a C++ plugin.

New project — nothing to do by hand

Ask the agent to run ue_project_create. It writes the .uproject with the required plugins enabled, the security flags Remote Control needs, and an init_unreal.py that starts the web server on every editor launch.

ue_engine_list  →  ue_project_create  →  ue_editor_open  →  ue_status

Existing project — two steps

1. Enable the plugin: Edit ▸ Plugins → Python Editor Script Plugin. Restart when prompted.

2. Tick one box: Edit ▸ Project Settings → search Python → check Enable Remote Execution.

That is the whole setup. The server discovers the editor over the engine's own Python remote execution channel — no config file, no HTTP port.

The native channel finds the editor with a UDP multicast ping on the local machine. That is the easy path, but it does not cross a subnet, and some corporate networks and VPN adapters swallow multicast entirely. In those cases — or with the editor on another machine — use the Remote Control API instead, with UE_MCP_TRANSPORT=remotecontrol.

1. Enable the plugins: Python Editor Script Plugin and Remote Control API. Restart when prompted.

2. Allow remote Python. Create Config/DefaultRemoteControl.ini:

   [/Script/RemoteControlCommon.RemoteControlSettings]
   bAutoStartWebServer=True
   bAutoStartWebSocketServer=True
   RemoteControlHttpServerPort=30010
   bEnableRemotePythonExecution=True
   bAllowAnyRemoteFunctionCall=False
   +CustomAllowedRemoteFunctionCalls=(ClassPath="/Script/PythonScriptPlugin.PythonScriptLibrary")
   bAllowConsoleCommandRemoteExecution=False

   These are two separate gates — one unlocks the object, the other the function call — and they fail with different errors. DefaultEngine.ini is the wrong file: URemoteControlSettings is declared UCLASS(config = RemoteControl). Restart the editor.

   On engines that predate some of these keys they are simply ignored — older versions did not gate those calls in the first place.

   The server listens on 127.0.0.1 only, so remote Python execution is not reachable from outside the machine.

   What the server can do once connected, and how to open it up safely if you really need to reach the editor from another machine, is in SECURITY.md.

   bAllowConsoleCommandRemoteExecution stays off. It enables ExecuteConsoleCommand through the web API, which this server never calls — the console commands it does need (LiveCoding.Compile, WebControl.StartServer, HighResShot) are issued from inside Python via unreal.SystemLibrary.execute_console_command and do not go through that gate. Older versions of this project set it to True; existing projects can flip it to False without losing anything.

3. Check it: open http://127.0.0.1:30010/remote/info in a browser. JSON back means you are connected.

Which transport is in use

ue_status reports it. By default (UE_MCP_TRANSPORT=auto) the server tries the native channel first and falls back to HTTP, so a project set up either way just works. Set pyremote or remotecontrol to pin one.

What it can do

Full parameter list in docs/TOOLS.md.

Working around the Blueprint graph limit

Blueprint node graphs cannot be authored from Python. EdGraph.Nodes is protected, pins are not exposed and there is no linking API — this is a hard limit of the engine, not of this server. Details in docs/UNREAL-NOTES.md.

What works instead: put the logic in a C++ parent class. The Blueprint stays the container for components and tweakable values; the behaviour is inherited.

ue_cpp_class_create      # writes the class, and the whole C++ module if the
                         # project was Blueprint-only
ue_editor_close
ue_build_start           # poll ue_build_status until running=false
ue_editor_open
ue_reparent_blueprint    # the Blueprint now inherits the behaviour

Blueprint variables whose names match a UPROPERTY on the new parent are absorbed by it, so values set in the editor survive the move. Functions marked BlueprintCallable become callable from the graph — an agent can build the vocabulary the designer then wires up by hand.

Material graphs, unlike Blueprint graphs, are fully scriptable: ue_create_material really does create and connect the nodes.

Other limits

• Compiling C++ needs the editor closed, unless the change only touches function bodies — then ue_live_compile works with it open.

• Packaging always needs the editor closed: the build step rewrites the DLLs the editor holds in memory.

• Feature availability varies with the engine version — see the compatibility table; ue_status reports what the running engine supports.

• Fab/Marketplace content has no public API. Those tools shell out to the community client legendary.

Configuration

If the engine sits somewhere unusual, you can also drop an mcp_engine.txt next to the .uproject containing its path, or pass engine_root explicitly.

Development

The test suite runs without Unreal installed: tests/fake_unreal.py stands in for the unreal module and tests/fake_server.py emulates the Remote Control API while actually executing the generated snippets — so the whole chain tool → snippet → harness → result is covered.

pip install -e ".[dev]"
pytest -q

Adding a tool: a reusable helper in src/unreal_mcp/ue_side.py (editor side), an @mcp.tool() function in server.py, and a test in tests/. See CONTRIBUTING.md for the conventions worth knowing.

ue_side.py is installed into the running editor as a module and keyed by a hash of its source, so editor-side changes take effect on the next call without restarting the server — and every other call is just a small snippet that imports it. Changes to server.py or local.py need a client restart.

Troubleshooting

Licence

MIT — see LICENSE.

References

• Remote Control for Unreal Engine

• Remote Control Quick Start

• Importing glTF files

• Poly Haven API · ambientCG API