Install Blueprint Stack
Drop the plugin into UE 5.4+ from FAB. The MCP server starts automatically on editor launch.
Codex CLI for Unreal Engine
Drive Unreal Engine from the OpenAI Codex CLI
Blueprint Stack turns Unreal Engine 5.4+ into an MCP server. Codex can read your project, edit Blueprints, generate materials, and ship gameplay without ever leaving the chat.
Built for OpenAI Codex CLI users who want Codex to act on the editor, not just describe what to do. 48 first-party tools cover Blueprints, animations, materials, Niagara VFX, levels, data tables, and asset generation.
Live editor session
Blueprint Stack
prompt / Spin up a top-down twin-stick controller with bullet pooling.
complete / Codex creates the Pawn, configures input mapping, builds a bullet Blueprint, and wires an object pool for spawn/despawn.
Workflow
How Codex drives the Unreal Editor
Connect Codex once and let it operate Unreal directly through structured tool calls.
Wire up Codex CLI
Add the MCP endpoint to your Codex CLI config. Codex now has full editor reach in every session.
Build in the chat
Ask Codex to scaffold gameplay, materials, or VFX. Tool calls run against the live editor in real time.
Examples of Codex on a real project
These are the kinds of prompts Codex turns into actual Unreal changes.
Prompt / 01
"Spin up a top-down twin-stick controller with bullet pooling."
Result
Codex creates the Pawn, configures input mapping, builds a bullet Blueprint, and wires an object pool for spawn/despawn.
Prompt / 02
"Create a stylized water material with foam at intersections."
Result
Codex authors the material, adds depth-fade-driven foam, and exposes wave amplitude and color as parameters.
Prompt / 03
"Set up an enemy AI Blueprint that patrols and attacks on sight."
Result
Codex creates the AI controller, behavior tree, blackboard keys, and links them to a patrol Blueprint with sight perception.
Prompt / 04
"Add a quest data table with branching objectives."
Result
Codex builds the struct, generates the data table, seeds branching rows, and wires a quest manager Blueprint to query them.
FAQ
Frequently asked questions
Does this work with the OpenAI Codex CLI?+
Yes. Blueprint Stack speaks MCP, the same protocol Codex CLI uses for tools. Add the server to your config and Codex can drive Unreal end to end.
Do I need an OpenAI API key?+
You use your own Codex CLI / OpenAI account. Blueprint Stack is the bridge between the agent and the editor — it does not proxy LLM tokens.
Which Unreal Engine versions are supported?+
Unreal Engine 5.4 and newer. Install through FAB; the plugin starts the MCP server when the editor opens.
Can I use Claude Code instead of Codex?+
Yes. The plugin is agent-agnostic. Claude Code, Codex, custom agents, and any MCP-compatible client all work.
How is this different from copy-pasting code from Codex?+
Codex calls real editor tools — it actually builds the asset, wires the Blueprint, and saves the change. You see the result in the editor immediately.
Blueprint Stack
Bring Codex into your Unreal Engine project
One-time purchase, lifetime updates. Install Blueprint Stack and let Codex build alongside you.