Skip to content

Getting Started

⏱ ~5 minutes

UE-MCP lets you tell an AI assistant what you want done in Unreal. It can place actors, write blueprints, author materials, configure Niagara, build lighting, generate PCG systems, blah, blah, blah.

Prerequisites

  1. Install Unreal Engine 5.4 to 5.7
  2. Install Node.js 18 or newer
  3. Install an MCP-capable AI client (e.g. Claude Code)

1. Installation

  1. If your Unreal Editor is open, close it.
  2. cd into your project folder (the one with the .uproject).
  3. Run the wizard:
npx ue-mcp init

The wizard then:

  1. Auto-detects your .uproject.
  2. Asks which tool categories to enable (level, blueprint, material, niagara, etc.), with one-line descriptions. Pre-checked on a fresh install; on re-init, prior opt-outs in ue-mcp.yml's ue-mcp.disable[] are remembered.
  3. Copies the C++ bridge plugin into <YourProject>/Plugins/UE_MCP_Bridge/.
  4. Enables the plugins it needs in your .uproject: UE_MCP_Bridge, PythonScriptPlugin, plus any of Niagara, PCG, GameplayAbilities, EnhancedInput required by the categories you kept.
  5. Scaffolds an empty ue-mcp.yml (for custom flows) if missing.
  6. Detects installed MCP clients (Claude Code project + global, Claude Desktop, Cursor, Codex) and writes the config for each you confirm. Global/Desktop configs default unchecked since opting them in affects every project on the machine.
  7. Asks about agent behavior (all default off on fresh installs — blasting through with Enter adds no surprises): enable the feedback(submit) tool, install the Claude-Code-only PostToolUse hook that nudges the agent to offer feedback after execute_python, install bundled Claude Code workflow skills.
  8. If you opted into the feedback prompt hook, optionally runs the GitHub OAuth device flow so feedback(submit) can author issues as your real GitHub user (default author="user"). The token is cached at ~/.ue-mcp/auth.json (mode 600) and reused. Skip if you don't want it now — you can run npx ue-mcp auth later, or call feedback(submit) with author="bot" to post anonymously instead.
  9. Writes the final ue-mcp.yml and prints a recap of every file or directory init touched. Per-machine state (e.g. the list of Claude Code settings files where the feedback hook was installed) is kept under ~/.ue-mcp/, not in the project tree.

2. Open the Editor

  1. Open your project.
  2. When the editor asks whether to compile UE_MCP_Bridge, say yes. First-time compile takes ~30-60 seconds.

The bridge starts automatically once the editor finishes loading, listening on ws://localhost:9877.

Verify the bridge

  1. Open Window → Output Log.
  2. Filter on LogMCPBridge.
  3. Confirm this line appears:
LogMCPBridge: [UE-MCP] Bridge listening on ws://localhost:9877

If it's not there, see Troubleshooting.

3. Verify the connection

  1. Open your AI client.
  2. Paste:
Run project(action="get_status").
  1. Look for "editorConnected": true in the response.

4. Try things

Good first prompts:

What's in my level right now?

List all blueprints under /Game/Blueprints.

Place a directional light at (0, 0, 500), a SkyLight at the origin, then build lighting at preview quality.

Run the Neon Shrine demo so I can see what you can build.

Read the Blueprint at /Game/Blueprints/BP_Player and explain what it does.

Direct tool-call syntax also works:

level(action="get_outliner")
asset(action="list", directory="/Game/")
demo(action="step", stepIndex=1)
reflection(action="reflect_class", className="StaticMeshActor")

See the Tool Reference for everything available.

Updating

Update, deploy, and rebuild in one command (run from a plain terminal, not through your MCP client):

ue-mcp update --build          # update npm package, deploy plugin, rebuild editor, print the doctor table

Or do less:

ue-mcp update --deploy         # update + deploy plugin sources (no rebuild)
ue-mcp update                  # update the npm package only
ue-mcp deploy                  # copy plugin sources into your project

update cannot restart the MCP server it was spawned by, so finish with: quit your MCP client → ue-mcp update --build → relaunch the client.

ue-mcp doctor

If an update "succeeds" but the running server keeps reporting an old version, run:

ue-mcp doctor

It prints every version source - registry latest, npm global, the running server(s), the deployed bridge plugin - and, crucially, flags a project-local node_modules/ue-mcp that shadows the global install. With ue-mcp pinned in a project's package.json, npx ue-mcp runs the local copy, so global updates do nothing. doctor surfaces that one-line root cause (and suggests pinning .mcp.json to npx -y ue-mcp@latest so the server self-heals on each launch). ue-mcp update --build aligns a stale local copy automatically.

Building the project

To build your project's C++ code from the command line:

npx ue-mcp build

Stop the editor first. Pass a .uproject path if you're not in the project directory. AI agents can also trigger builds via editor(action="build_project").

Unattended agent sessions

If you set up the feedback prompt hook and then leave a long-running agent working, the elicitation approval prompt on feedback(submit) will stall the session waiting for you. For unattended runs, switch your personal feedback mode:

npx ue-mcp feedback mode defer          # or: auto-approve

This writes the preference to ~/.ue-mcp/state.json (per-user, per-machine — it is not committed to the project). defer writes submissions to ~/.ue-mcp/pending-feedback/ for later review with npx ue-mcp feedback list/show/approve/discard. auto-approve posts directly without prompting. Both still run the credential and privacy scrubs.

For a one-off agent run without changing the persisted preference, use the env var instead:

UE_MCP_FEEDBACK_MODE=defer npx ue-mcp ./MyGame.uproject

See Feedback → modes.

Switching projects

To point ue-mcp at a different .uproject without restarting your AI client, ask:

Switch to the project at C:/path/to/Other.uproject.

UE-MCP redeploys the bridge and reconnects. (Calls project(action="set_project") under the hood.)

Manual configuration

If you'd rather skip npx ue-mcp init, edit the MCP client config yourself.

Use forward slashes on Windows

C:/Users/..., not C:\Users\.... Backslashes need escaping inside JSON.

.mcp.json in your project root: 

{
  "mcpServers": {
    "ue-mcp": {
      "command": "npx",
      "args": ["ue-mcp", "C:/path/to/MyGame.uproject"]
    }
  }
}

claude_desktop_config.json: 

{
  "mcpServers": {
    "ue-mcp": {
      "command": "npx",
      "args": ["ue-mcp", "C:/path/to/MyGame.uproject"]
    }
  }
}

.cursor/mcp.json: 

{
  "mcpServers": {
    "ue-mcp": {
      "command": "npx",
      "args": ["ue-mcp", "C:/path/to/MyGame.uproject"]
    }
  }
}

~/.codex/config.toml: 

[mcp_servers.ue-mcp]
command = "npx"
args = ["ue-mcp", "C:/path/to/MyGame.uproject"]
cwd = "C:/path/to"
enabled = true

The first run auto-deploys the C++ plugin. To deploy explicitly: npx ue-mcp deploy, then restart the editor.

Where to next