# realvirtual.io MCP Server

Give AI agents full control over your Unity Editor — scenes, GameObjects, components, simulation, digital twins, and more.

<figure><img src="https://260262196-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FpYxFg97YnJX96UzNNTSd%2Fuploads%2Fgit-blob-37405c5f256658d7f8f4736477f30e02240838a6%2Fmcp-overview.png?alt=media" alt=""><figcaption><p>MCP Server running in Unity with 91 tools available for AI agents</p></figcaption></figure>

## Overview

The realvirtual MCP Server is a free, open-source Unity package that implements the [Model Context Protocol (MCP)](https://modelcontextprotocol.io). It lets AI agents like **Claude**, **Cursor**, or any MCP-compatible client interact with Unity in real time.

The package works with **any Unity project** — including industrial digital twins, robotics simulation, and virtual commissioning.

### How It Works

```
AI Agent (Claude Desktop / Claude Code / Cursor)
    |
    | MCP Protocol (stdio or SSE)
    v
Python MCP Server
    |
    | WebSocket (JSON, Port 18711)
    v
Unity Package (C# WebSocket server + tool registry)
```

The package runs a WebSocket server inside the Unity Editor. When an AI agent sends a tool call, the Python MCP server forwards it over WebSocket to Unity, which executes it on the main thread and returns the result.

### Key Features

* **Works with any Unity project** — Not tied to a specific framework or asset
* **Zero Python knowledge needed** — Define tools in C#, the language you're already using
* **Auto-discovery** — Tools are found via reflection, no manual registration
* **90+ built-in tools** — Scene, GameObjects, components, transforms, simulation, screenshots, and more
* **Extensible in minutes** — Add `[McpTool]` to any static method and it's available to AI agents
* **Self-contained** — Ships with embedded Python 3.12, no system Python required
* **One-click setup** — Download Python server and configure Claude from the Unity toolbar
* **Survives domain reloads** — Auto-reconnects after Unity recompiles scripts
* **Multi-instance support** — Run multiple Unity instances, each with its own MCP server

### Digital Twin Tools with realvirtual

When combined with the [realvirtual](https://realvirtual.io) framework, you get additional MCP tools purpose-built for industrial digital twins and virtual commissioning:

* **Drives** — Control motors, actuators, conveyors
* **Sensors** — Read industrial sensors
* **PLC Signals** — Read/write PLC I/O
* **Robot IK** — Inverse kinematics control

This enables AI agents to operate complete virtual factory simulations — move robots, control conveyors, read sensors, and interact with PLC programs in real time.

### Toolbar Status

The toolbar brain icon shows connection state:

| Color  | Meaning                              |
| ------ | ------------------------------------ |
| Gray   | Server stopped                       |
| Yellow | Server running, no clients connected |
| Green  | Client(s) connected                  |

The activity label next to it shows the currently executing tool call with elapsed time.

## Links

* **GitHub (Unity Package):** [github.com/game4automation/io.realvirtual.mcp](https://github.com/game4automation/io.realvirtual.mcp)
* **GitHub (Python Server):** [github.com/game4automation/realvirtual-MCP](https://github.com/game4automation/realvirtual-MCP)
* **License:** MIT

{% hint style="info" %}
This package is provided as-is. For commercial customers of [realvirtual](https://realvirtual.io), we offer professional services for digital twin development, virtual commissioning, and AI agent integration.
{% endhint %}