Editor starts the server
The plugin boots an MCP server on port 9315 the moment the Unreal Editor opens. No extra processes to manage.
MCP Server for Unreal Engine
A built-in MCP server for Unreal Engine
Blueprint Stack ships an MCP server inside Unreal Engine 5.4+. JSON-RPC over HTTP on port 9315, 48 tools, agent-agnostic. Connect Claude Code, Codex CLI, or any MCP client.
Tools cover Blueprints, animations, materials, Niagara VFX, levels, data tables, structs, asset generation, and more. The transport is plain JSON-RPC, so any MCP-compatible host can wire it up in minutes.
Live editor session
Blueprint Stack
prompt / create_blueprint / add_node / connect_pins
complete / Build a Blueprint from scratch, drop nodes into the graph, and connect pins programmatically through MCP.
Workflow
How the MCP server works
Standards-based MCP. No custom SDK, no proprietary lock-in.
Your client connects
Add the endpoint to Claude Code, Codex CLI, or your own MCP host. The full tool catalog is discovered automatically.
Tools run live
Each tool call mutates the editor in real time — Blueprints wire themselves, materials get authored, assets land in the Content Browser.
What the tool catalog covers
A representative slice of the 48 MCP tools exposed by Blueprint Stack.
Prompt / 01
"create_blueprint / add_node / connect_pins"
Result
Build a Blueprint from scratch, drop nodes into the graph, and connect pins programmatically through MCP.
Prompt / 02
"create_material / add_material_node"
Result
Author materials node-by-node, including parameters, samplers, math nodes, and emissive/normal output wiring.
Prompt / 03
"create_niagara_system / add_emitter"
Result
Build VFX systems and emitters with full module configuration directly from MCP tool calls.
Prompt / 04
"create_struct / create_data_table / add_row"
Result
Define data structures, generate data tables, and seed rows for stats, dialogue, quests, or loot tables.
FAQ
Frequently asked questions
Is this a real Model Context Protocol server?+
Yes. Blueprint Stack implements MCP using JSON-RPC over HTTP on port 9315. Any MCP-compatible client can discover and call its tools.
Which clients work with it?+
Claude Code, OpenAI Codex CLI, custom agents built on the MCP SDK, and any host that speaks MCP. The server is agent-agnostic.
How many tools does the server expose?+
48 tools across 11 categories: Blueprints, animations, materials, levels, Niagara VFX, data, structs, sequences, lighting, asset generation, and editor utilities.
Can I add my own MCP tools?+
The server runs in-process inside Unreal. The current build does not expose a public extension API for custom tools, but the roadmap includes user-authored tool registration.
Does the server require an internet connection?+
No. The MCP server itself runs locally on your machine. Only your AI agent needs network access to call its model.
Blueprint Stack
An MCP server purpose-built for Unreal
Install Blueprint Stack on UE 5.4+ and connect any MCP client. One-time purchase, lifetime updates.