uMCP

uMCP is a lightweight, Unity‑centric implementation of the Model Context Protocol (MCP) that enables AI assistants—such as Claude, VSCode Agent Mode, Cursor, or CLINE—to interact directly with Unity applications over a simple Streamable HTTP channel. By eliminating the need for external runtimes (Python, Node.js, etc.), uMCP delivers a fast, low‑overhead bridge between AI agents and game engines, making it ideal for developers who want to embed intelligent behavior or procedural content generation into their Unity projects without adding complex server stacks.

At its core, uMCP exposes a set of pre‑authorized operations that the AI can invoke. This safety model ensures that arbitrary code execution is impossible; every command must be explicitly defined and registered via the attribute. The framework ships with a collection of management tools—such as world‑editing commands for VRChat or other Unity environments—that can be leveraged out of the box, and developers can extend these capabilities with custom commands in a few lines of code. The result is a highly modular system where new tools can be added without touching the underlying networking layer.

For developers, uMCP offers a seamless workflow: once the Unity project is running, the MCP server starts automatically and listens on . AI clients that support Streamable HTTP can connect immediately, send prompts, and receive structured responses or execute commands like spawning objects, querying scene state, or manipulating physics. This tight integration allows for real‑time AI control of gameplay mechanics, dynamic content creation, or automated testing scenarios—all without leaving the Unity editor.

Real‑world use cases abound. In game development, an AI assistant can generate level layouts or adjust enemy behavior on the fly, responding to player feedback in real time. In educational settings, students can experiment with AI‑driven tutorials that manipulate the Unity scene to demonstrate concepts. For VRChat creators, uMCP’s world‑tools enable rapid prototyping of interactive environments that respond to natural language commands. Because the server is built into Unity, latency is minimal and debugging remains straightforward—developers can inspect command registrations directly within the editor.

What sets uMCP apart is its minimalistic footprint combined with a robust safety model and easy extensibility. By leveraging Streamable HTTP, it sidesteps the overhead of heavier MCP implementations while still offering a full suite of tools and prompts. This makes it an attractive choice for teams that need reliable, secure AI integration in Unity without the complexity of external services.