Funplay Unreal MCP

io.github.FunplayAIPublished by GitHub account FunplayAIv0.2.0Updated Oct 24, 2026

stdio bridge for the local Unreal Editor MCP server from FunplayAI/funplay-unreal-mcp.

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Overview

AI-generated overview

Node.js stdio bridge that lets an AI assistant drive a running Unreal Editor through the Funplay MCP plugin: actors, levels, Blueprints, materials, assets and…

What you can do
  • Run arbitrary Python in the editor and console commands, with API search and class inspection
  • Spawn, transform, attach and delete actors, add components, and build walls, floors and stairs
  • Create and edit Blueprints, materials and material instances, and import, rename, save or delete assets
  • Manage levels, Play-In-Editor sessions, viewport camera, selection, screenshots and undo/redo
  • Read and write files, build data tables, create UMG widgets, spawn Niagara effects and read project, level and log resources
When to use it
Useful when you work in Unreal Engine 5.3–5.8 and want an assistant to build or modify levels, Blueprints, materials and assets inside a live editor, or to script editor actions through Python instead of clicking.
Requirements
A local Unreal Editor with the FunplayMCP plugin installed and its server started, plus Node.js for the npx bridge. The plugin generates a per-project token that must be supplied as FUNPLAY_UNREAL_MCP_TOKEN; the endpoint defaults to a local loopback address and can be overridden with FUNPLAY_UNREAL_MCP_URL. Desktop only.
Before you install
The token is a credential stored in the project's settings file; keep it out of shared configs. The execute_python tool runs arbitrary Python in the editor and its safety checks can be disabled per call, so it can read or write files and run processes. Many tools write, rename, delete or save assets, levels and Blueprints, and Play-In-Editor changes editor state.

Installation

In SourceWeft

  1. Open Funplay Unreal MCP in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

Funplay MCP for Unreal

The most advanced MCP server for the Unreal Editor.

[Unreal Engine 5.3-5.8] [MIT] [MCP compatible] [Editor only]

中文 | English

💖 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.
  • Prompts: level_review, feature_plan, debug_runtime, blueprint_actor.
  • Resources: unreal://project/context, unreal://project/info, unreal://level/current, unreal://actors/list, unreal://selection/current, unreal://tools/catalog, unreal://logs/recent, unreal://interaction/history, plus templates unreal://actor/{ref} and unreal://asset/{path}.

Comparison with Funplay MCP for Unity

Funplay MCP for UnrealFunplay MCP for Unity
Editor sidePure-Python plugin (no build)C# package
Primary executionexecute_python (embedded unreal)execute_code (in-memory C#)
TransportLocal HTTP + stdio bridgeLocal HTTP + stdio bridge
Default exposurecore profile (32 of 97)core profile
Engine versionsUE 5.3–5.8Unity 2022.3+
Client configOne-click (Claude/Cursor/VS Code/Codex)One-click

Built-in Tools

97 built-in tools (32 core). Call get_tool_catalog for the live list.

CategoryTools
Executionexecute_python, run_console_command
Reflectionsearch_api, describe_class, list_enum_values, inspect_object
Actorsspawn_actor, spawn_actor_from_asset, destroy_actor, duplicate_actor, set_actor_transform, set_actor_label, set_actor_property, attach_actor, get_actor_info, list_actors, find_actors, batch_spawn_actors
Componentsadd_component, list_components, get_component_properties, set_component_property, set_static_mesh, set_material, set_physics_properties, add_ism_instances
Assetslist_assets, find_assets, get_asset_info, duplicate_asset, rename_asset, delete_asset, save_asset, import_asset, create_folder, asset_exists, get_asset_references
Blueprintscreate_blueprint, add_blueprint_component, compile_blueprint, get_blueprint_info, spawn_blueprint
Materialscreate_material, create_material_instance, set_material_instance_parameter, get_material_info, add_material_expression, connect_material_expressions, connect_material_property, recompile_material
Levelsnew_level, load_level, save_current_level, save_all_dirty, get_level_info, list_levels
Play-In-Editorplay_in_editor, stop_play_in_editor, simulate_in_editor, get_play_state
Viewportset_viewport_camera, get_viewport_camera, focus_viewport
Screenshotstake_screenshot
Selectionget_selection, set_selection, select_none, get_selected_assets
Editor Stateget_editor_state, get_project_info, get_output_log, sync_content_browser, health_status, undo, redo
Filesread_file, write_file, list_directory, file_exists
Proceduralbuild_wall, build_floor, build_stairs, scatter_actors
Organizationset_actor_folder, create_layer, add_actors_to_layer, list_layers
Datacreate_data_table, get_data_table, set_data_table_rows, export_data_table_csv
UMGcreate_widget_blueprint, add_widget, set_widget_property
Effectsspawn_niagara_system, set_niagara_parameter
Discoveryget_tool_catalog

Repository Layout

FunplayMCP/                         # the Unreal editor plugin (pure Python)  FunplayMCP.uplugin  Content/Python/    init_unreal.py                  # auto-run entry point    funplay_mcp/                    # server, transport, registry, providers      tools/                        # one module per tool categorystdio-wrapper/                      # zero-dependency Node.js stdio<->HTTP bridgescripts/                           # validate_repo.py, package_release.pytests/                             # Node + Python tests (run without the editor)server.json                        # MCP registry manifest

Architecture

AI client (Claude Code / Cursor / ...)        │  stdio (MCP JSON-RPC)        ▼funplay-unreal-mcp  (Node bridge, npx)        │  HTTP + token  →  127.0.0.1:8765        ▼Unreal Editor plugin (Python)        │  game-thread pump (register_slate_post_tick_callback)        ▼unreal API  →  Actors / Assets / Blueprints / Levels / PIE

Contributing

See CONTRIBUTING.md. Run python3 scripts/validate_repo.py before opening a PR.

License

MIT — see LICENSE.

Source: README.md at commit 688c21f

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

1
  1. v0.2.0LatestSep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts