stdio bridge for the local Unreal Editor MCP server from FunplayAI/funplay-unreal-mcp.
io.github.FunplayAI/funplay-unreal-mcp (MCP)
This MCP server provides a stdio bridge for the local Unreal Editor server from FunplayAI’s funplay-unreal-mcp. It is intended to be used with the Model Context Protocol (MCP) and targets Unreal Engine 5.3–5.8 in an editor-only context.
🛠️ Key Features
Stdio bridge for a local Unreal Editor MCP server
MCP-compatible
Unreal Engine support: 5.3–5.8
Editor-only
🚀 Use Cases
Connect MCP-based tooling to the Unreal Editor
Enable LLM or AI-tool workflows in Unreal Editor sessions
💖 If this saves you time, please star the repo — it helps a lot.
Funplay MCP for Unreal lets AI assistants — Claude Code, Cursor, Windsurf, Codex,
VS Code Copilot and any other MCP client — operate directly inside a running
Unreal Editor. It is a pure-Python editor plugin (no C++ build, works across
Unreal Engine 5.3–5.8) that exposes the editor over a local MCP server, plus a
tiny Node.js stdio bridge that connects your AI client to it. MIT-licensed and
free for commercial use.
Describe what you want in natural language — spawn and arrange actors, build
levels and Blueprints, create materials, import assets, drive Play-In-Editor,
capture screenshots, or run arbitrary execute_python — and let the assistant
do it.
"Build a small arena: a floor, four walls, some point lights, and a player
start in the middle. Then play it and send me a screenshot."
The assistant inspects the level, spawns and positions the actors, sets up
lighting, enters Play-In-Editor, and returns a screenshot — all through this
MCP server.
Demo
Codex uses Funplay MCP to build a castle in Unreal Editor
Codex asks for a castle, Funplay MCP drives the Unreal Editor through MCP, and
the finished scene appears directly in the editor.
Quick Start
Three things: (1) drop the plugin into your project, (2) enable it and
start the server, (3) point your AI client at it.
1. Install the plugin
💡 The plugin is pure Python — there is nothing to compile.
Copy the FunplayMCP/ folder into your project's Plugins/ directory
(<YourProject>/Plugins/FunplayMCP/), or download
Funplay.UnrealMcp.vX.Y.Z.zip from the latest Release
and extract it there.
It depends on the engine's Python Editor Script Plugin, which the
.uplugin enables automatically.
2. Enable and start the MCP Server
Open your project. In Edit → Plugins, confirm Funplay MCP for Unreal is
enabled, then restart the editor if prompted.
On startup the server listens at http://127.0.0.1:8765/ by default. If the
port is busy it automatically picks a free local port (and a second editor of
the same project attaches to the existing server).
A per-project auth token is generated and stored in
<YourProject>/Saved/FunplayMCP/funplay_mcp_settings.json.
Get the endpoint and token any time from **Tools → Funplay MCP → Log Endpoint
Token** (printed to the Output Log).
3. Configure your AI client
The fastest path is the editor menu: Tools → Funplay MCP → Configure Claude
Code (or Cursor / VS Code / Codex). It writes the right config with the
endpoint and token filled in.
Manual configuration
Claude Code (~/.claude.json), Cursor (~/.cursor/mcp.json):
json
{"mcpServers":{"funplay-unreal":{"command":"npx","args":["-y","funplay-unreal-mcp"],"env":{"FUNPLAY_UNREAL_MCP_URL":"http://127.0.0.1:8765/","FUNPLAY_UNREAL_MCP_TOKEN":"<token from the Funplay MCP menu>"}}}}
VS Code (mcp.json) uses the servers key; Codex
(~/.codex/config.toml) uses a [mcp_servers."funplay-unreal"] table. Both are
written for you by the one-click menu.
4. Verify the connection
Ask your assistant to:
call get_project_info,
read the resource unreal://project/context,
run execute_python with result = unreal.SystemLibrary.get_engine_version().
Before You Start
Editor only. The server runs inside the Unreal Editor; it does not ship in
packaged games.
Loopback only. It binds 127.0.0.1 and rejects non-loopback Origins; POST
requests require the per-project auth token.
Default core profile. A focused 32-tool set is exposed by default; switch
to full (97 tools) in the settings file when you want everything.
execute_python safety checks are on by default (a filesystem/process
denylist); pass safety_checks=false to override per call.
All unreal API work is marshalled onto the game thread, so the editor never
crashes from off-thread access.
Why This Project
execute_python first. A first-class tool that runs arbitrary Python in
the editor — anything the 96 dedicated tools don't cover, you can still do.
API discovery built in.search_api / describe_class / inspect_object
read the embedded unreal module's own docs, so the assistant uses the real
API instead of hallucinating it.
Pure Python, no build. No C++ module, no compile step, portable across UE
5.3–5.8.
Safe by construction. Game-thread marshalling, loopback binding, auth
token, and DNS-rebinding protection out of the box.
One-click client config + project skills. Configure Claude Code / Cursor /
VS Code / Codex and generate an AGENTS.md bridge from the editor menu.
Same family, same conventions as Funplay MCP for Unity / Godot / Cocos.
Highlights
97 built-in tools (32 in the default core profile) across 20 categories.
MCP resources (unreal://...) for project, level, selection, logs, and the
tool catalog, plus prompt templates for common workflows.
Structured results — every tool returns JSON the assistant can reason over;
screenshots come back as inline images.
Auto port-fallback and same-project instance attach.
Zero-dependency Node bridge published to npm as funplay-unreal-mcp.
MCP Capabilities
Tools: 97 (32 core / 97 full).
Primary execution:execute_python — run any Python snippet in the editor.
