MCP Tutorial Series
Model Context Protocol (MCP) lets an AI agent - Claude Code, Cursor, VS Code Copilot, Gemini, or Codex - talk to your open Unreal Editor over a small local server. The agent can read your source, query the Asset Registry, inspect a running Play-In-Editor session, and call tools you expose. This series takes you from never heard of MCP to my agent is driving my project and I have written my own tool.
Every lesson is paired with a short screencast script - see Video Walkthroughs - so you can read it, watch it, or both. Follow the parts in order; each one builds on the last.
What you will build
| Part | You will learn | End result |
|---|---|---|
| Part 1 - MCP Fundamentals | What MCP is, how to start Unreal's built-in MCP server, and how to connect any agent. | An agent that can read files and list plugins in your project. |
| Part 2 - The Crimson Toolsets | How to switch on the Crimson MCP layer and drive a live game session with it. | An agent that inspects and changes a running PIE session through Crimson tools. |
| Part 3 - Author Your Own | How to write and register a UToolsetDefinition with your own AI-callable tools. | A custom tool your agent can discover and call. |
Requires two experimental engine plugins
MCP is powered by Epic's ModelContextProtocol and ToolsetRegistry plugins, both marked Experimental in UE 5.8 and both off by default. Part 1 turns them on. If your project already has any Crimson plugin installed, they are pulled in for you - you just need to enable them.
This is the tutorial - the reference lives elsewhere
These pages walk you through the flow once, in order. For the exhaustive lookup - every setting, every tool, the full toolset inventory - use CrimsonEditorUtilities -> API Reference and CrimsonCommon -> Concept: How Crimson MCP Works. This series links to them as you go.