UEAgent MCP server

UEAgent

The MCP server for Unreal Engine 5, built into the editor. More than 1,500 tools that let Claude Code, Cursor or any MCP client build in Unreal, with every change checked before it runs and read back after.

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UEAgent is an Unreal Engine 5.7 and 5.8 editor plugin that lets AI agents operate the editor through the Model Context Protocol. The plugin is the server: it serves Streamable HTTP from inside the editor, with no Python or Node process in between.

Why UEAgent

montages, IK, Pose Search), Niagara, landscapes and foliage, World Partition, PCG, Sequencer, UMG/CommonUI/MVVM, GAS, AI (Behavior Trees, StateTree, EQS, Smart Objects), audio and MetaSounds, USD and Interchange, PIE control and inspection: see the tool reference.

• The whole engine, not a demo. Blueprints and their graphs, materials, animation (AnimBP,

call goes through a contract:

• Verified, not assumed. An editor call that answers success: true proves nothing, so every

a zero that proves nothing or a change that landed in the wrong PIE world.

• preconditions refuse the calls known to crash or freeze the editor, and say what to do instead;
• readback re-reads the state after the call, and reports as failed a write that did not stick,

reverts it. Vendored libraries listed as Read Only Content Roots cannot be saved, renamed, moved or deleted by any tool, and calls that are unreliable while Play-in-Editor runs are refused while it runs.

• Safe with your content. Every tool call is one undo step, named after the tool, so Ctrl+Z

threads, and every tool call runs on the game thread through one queue. The Activity panel (status bar > MCP > Activity) lists each call with its duration and outcome.

• Built for real sessions. Several agents can share one editor: protocol work runs on network

flowchart LR
    A["AI agent<br/>Claude Code, Cursor, ..."] -- "MCP over HTTP" --> P
    subgraph E["Unreal Editor + UEAgent"]
        P["Preconditions<br/>refuse known crashes"] --> H["Tool<br/>1,500+ of them"] --> R["Readback<br/>re-read the state"]
    end
    R -- "verified result" --> A

How a server inside the editor differs from one outside it, and the questions to ask any MCP server for Unreal: Choosing an MCP server.

Quick start

Let your agent do it. Open Claude Code, Cursor, Codex or another agent in your project's folder and paste:

Install the UEAgent plugin in this Unreal Engine project and connect yourself to it, following https://raw.githubusercontent.com/CarlxsMG/UEAgent/main/llms-install.md

Shortened. The full README is on GitHub.