MCP Server for Agentic Coding

Summary

Reactor's documentation is published with a hosted MCP server, so AI coding agents can read the docs directly. Paired with Unity's MCP server, an agent can look up how Reactor works and apply it in your project without leaving the editor.

Agentic coding tools speak the Model Context Protocol (MCP), a standard that connects an AI agent to outside services and lets it use them as tools. Two MCP servers cover most of a Reactor workflow: one that serves this documentation, and one that drives the Unity editor. Connecting both gives an agent the knowledge to write correct Reactor code and the reach to build the project it runs in.

The Reactor Documentation Server

The Reactor docs on GitBook expose a read-only MCP server. An agent connected to it searches these pages and pulls back the exact API surface, tutorial steps, and patterns it needs instead of guessing from memory. This keeps generated server and client scripts aligned with the current API.

The server URL is the docs site address followed by /~gitbook/mcp:

https://kinematicsoup.gitbook.io/reactor/~gitbook/mcp

Add it to your agent's MCP configuration as an HTTP server. In a client that uses a JSON config, the entry looks like this:

{
  "mcpServers": {
    "reactor-docs": {
      "url": "https://kinematicsoup.gitbook.io/reactor/~gitbook/mcp"
    }
  }
}

The server is read-only and covers the published documentation, including the API reference and every tutorial.

Pairing With the Unity Editor

Unity ships its own MCP server through the com.unity.ai.assistant package on Unity 6 and later. It gives an agent live access to the open project: the scene hierarchy, game objects, component values, and the console. Enable it under Edit -> Project Settings -> AI -> Unity MCP Server, then approve the connection when your agent first connects.

With the Unity server running, an agent can add a ksRoomType to a room object, attach a ksEntityComponent to a networked prefab, wire up server and client scripts, and read back compiler or runtime errors from the console.

A Cohesive Workflow

Running both servers together lets an agent handle a Reactor task from end to end:

1. Look up the pattern. The agent queries the Reactor documentation server for the relevant API and tutorial, such as sending an RPC or syncing an entity property.

2. Build in the scene. Through the Unity server, it creates or edits the room, entities, and prefabs the feature needs.

3. Write the scripts. It generates server, client, and common scripts that match the documented API.

4. Check the result. It reads the console for build and runtime errors, consults the docs again when something looks off, and corrects the code.

The documentation server keeps the agent accurate about Reactor. The Unity server gives it hands in the project. Together they cover the loop from reading how a feature works to watching it run.