mcpforunityserver 9.5.4b20260311053122

MCP for Unity Server: A Unity package for Unity Editor integration via the Model Context Protocol (MCP).

MCP for Unity Server

Model Context Protocol server for Unity Editor integration. Control Unity through natural language using AI assistants like Claude, Cursor, and more.

Maintained by Coplay - This project is not affiliated with Unity Technologies.

💬 Join our community: Discord Server

Required: Install the Unity MCP Plugin to connect Unity Editor with this MCP server. You also need uvx (requires uv) to run the server.

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Installation

Option 1: PyPI

Install and run directly from PyPI using uvx.

Run Server (HTTP):

uvx --from mcpforunityserver mcp-for-unity --transport http --http-url http://localhost:8080

MCP Client Configuration (HTTP):

{
  "mcpServers": {
    "UnityMCP": {
      "url": "http://localhost:8080/mcp"
    }
  }
}

MCP Client Configuration (stdio):

{
  "mcpServers": {
    "UnityMCP": {
      "command": "uvx",
      "args": [
        "--from",
        "mcpforunityserver",
        "mcp-for-unity",
        "--transport",
        "stdio"
      ]
    }
  }
}

Option 2: From GitHub Source

Use this to run the latest released version from the repository. Change the version to main to run the latest unreleased changes from the repository.

{
  "mcpServers": {
    "UnityMCP": {
      "command": "uvx",
      "args": [
        "--from",
        "git+https://github.com/CoplayDev/unity-mcp@v9.5.3#subdirectory=Server",
        "mcp-for-unity",
        "--transport",
        "stdio"
      ]
    }
  }
}

Option 3: Docker

Use Pre-built Image:

docker run -p 8080:8080 msanatan/mcp-for-unity-server:latest --transport http --http-url http://0.0.0.0:8080

Build Locally:

docker build -t unity-mcp-server .
docker run -p 8080:8080 unity-mcp-server --transport http --http-url http://0.0.0.0:8080

Configure your MCP client with "url": "http://localhost:8080/mcp".

Option 4: Local Development

For contributing or modifying the server code:

# Clone the repository
git clone https://github.com/CoplayDev/unity-mcp.git
cd unity-mcp/Server

# Run with uv
uv run src/main.py --transport stdio

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Configuration

The server connects to Unity Editor automatically when both are running. Most users do not need to change any settings.

CLI options

These options apply to the mcp-for-unity command (whether run via uvx, Docker, or python src/main.py).

• --transport {stdio,http} - Transport protocol (default: stdio)
• --http-url URL - Base URL used to derive host/port defaults (default: http://localhost:8080)
• --http-host HOST - Override HTTP bind host (overrides URL host)
• --http-port PORT - Override HTTP bind port (overrides URL port)
• --http-remote-hosted - Treat HTTP transport as remotely hosted
  • Requires API key authentication (see below)
  • Disables local/CLI-only HTTP routes (/api/command, /api/instances, /api/custom-tools)
  • Forces explicit Unity instance selection for MCP tool/resource calls
  • Isolates Unity sessions per user
• --api-key-validation-url URL - External endpoint to validate API keys (required when --http-remote-hosted is set)
• --api-key-login-url URL - URL where users can obtain/manage API keys (served by /api/auth/login-url)
• --api-key-cache-ttl SECONDS - Cache duration for validated keys (default: 300)
• --api-key-service-token-header HEADER - Header name for server-to-auth-service authentication (e.g. X-Service-Token)
• --api-key-service-token TOKEN - Token value sent to the auth service for server authentication
• --default-instance INSTANCE - Default Unity instance to target (project name, hash, or Name@hash)
• --project-scoped-tools - Keep custom tools scoped to the active Unity project and enable the custom tools resource
• --unity-instance-token TOKEN - Optional per-launch token set by Unity for deterministic lifecycle management
• --pidfile PATH - Optional path where the server writes its PID on startup (used by Unity-managed terminal launches)

Environment variables

• UNITY_MCP_TRANSPORT - Transport protocol: stdio or http
• UNITY_MCP_HTTP_URL - HTTP server URL (default: http://localhost:8080)
• UNITY_MCP_HTTP_HOST - HTTP bind host (overrides URL host)
• UNITY_MCP_HTTP_PORT - HTTP bind port (overrides URL port)
• UNITY_MCP_HTTP_REMOTE_HOSTED - Enable remote-hosted mode (true, 1, or yes)
• UNITY_MCP_DEFAULT_INSTANCE - Default Unity instance to target (project name, hash, or Name@hash)
• UNITY_MCP_SKIP_STARTUP_CONNECT=1 - Skip initial Unity connection attempt on startup

API key authentication (remote-hosted mode):

• UNITY_MCP_API_KEY_VALIDATION_URL - External endpoint to validate API keys
• UNITY_MCP_API_KEY_LOGIN_URL - URL where users can obtain/manage API keys
• UNITY_MCP_API_KEY_CACHE_TTL - Cache TTL for validated keys in seconds (default: 300)
• UNITY_MCP_API_KEY_SERVICE_TOKEN_HEADER - Header name for server-to-auth-service authentication
• UNITY_MCP_API_KEY_SERVICE_TOKEN - Token value sent to the auth service for server authentication

Telemetry:

• DISABLE_TELEMETRY=1 - Disable anonymous telemetry (opt-out)
• UNITY_MCP_DISABLE_TELEMETRY=1 - Same as DISABLE_TELEMETRY
• MCP_DISABLE_TELEMETRY=1 - Same as DISABLE_TELEMETRY
• UNITY_MCP_TELEMETRY_ENDPOINT - Override telemetry endpoint URL
• UNITY_MCP_TELEMETRY_TIMEOUT - Override telemetry request timeout (seconds)

Examples

Stdio (default):

uvx --from mcpforunityserver mcp-for-unity --transport stdio

HTTP (local):

uvx --from mcpforunityserver mcp-for-unity --transport http --http-host 127.0.0.1 --http-port 8080

HTTP (remote-hosted with API key auth):

uvx --from mcpforunityserver mcp-for-unity \
  --transport http \
  --http-host 0.0.0.0 \
  --http-port 8080 \
  --http-remote-hosted \
  --api-key-validation-url https://auth.example.com/api/validate-key \
  --api-key-login-url https://app.example.com/api-keys

Disable telemetry:

DISABLE_TELEMETRY=1 uvx --from mcpforunityserver mcp-for-unity --transport stdio

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Remote-Hosted Mode

When deploying the server as a shared remote service (e.g. for a team or Asset Store users), enable --http-remote-hosted to activate API key authentication and per-user session isolation.

Requirements:

• An external HTTP endpoint that validates API keys. The server POSTs {"api_key": "..."} and expects {"valid": true, "user_id": "..."} or {"valid": false} in response.
• --api-key-validation-url must be provided (or UNITY_MCP_API_KEY_VALIDATION_URL). The server exits with code 1 if this is missing.

What changes in remote-hosted mode:

• All MCP tool/resource calls and Unity plugin WebSocket connections require a valid X-API-Key header.
• Each user only sees Unity instances that connected with their API key (session isolation).
• Auto-selection of a sole Unity instance is disabled; users must explicitly call set_active_instance.
• CLI REST routes (/api/command, /api/instances, /api/custom-tools) are disabled.
• /health and /api/auth/login-url remain accessible without authentication.

MCP client config with API key:

{
  "mcpServers": {
    "UnityMCP": {
      "url": "http://remote-server:8080/mcp",
      "headers": {
        "X-API-Key": "<your-api-key>"
      }
    }
  }
}

For full details, see Remote Server Auth Guide and Architecture Reference.

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MCP Resources

The server provides read-only MCP resources for querying Unity Editor state. Resources provide up-to-date information about your Unity project without modifying it.

Accessing Resources:

Resources are accessed by their URI (not their name). Always use ListMcpResources to get the correct URI format.

Example URIs:

• mcpforunity://editor/state - Editor readiness snapshot
• mcpforunity://project/tags - All project tags
• mcpforunity://scene/gameobject/{instance_id} - GameObject details by ID
• mcpforunity://prefab/{encoded_path} - Prefab info by asset path

Important: Resource names use underscores (e.g., editor_state) but URIs use slashes/hyphens (e.g., mcpforunity://editor/state). Always use the URI from ListMcpResources() when reading resources.

All resource descriptions now include their URI for easy reference. List available resources to see the complete catalog with URIs.

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Example Prompts

Once connected, try these commands in your AI assistant:

• "Create a 3D player controller with WASD movement"
• "Add a rotating cube to the scene with a red material"
• "Create a simple platformer level with obstacles"
• "Generate a shader that creates a holographic effect"
• "List all GameObjects in the current scene"

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Documentation

For complete documentation, troubleshooting, and advanced usage:

📖 Full Documentation

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Requirements

• Python: 3.10 or newer
• Unity Editor: 2021.3 LTS or newer
• uv: Python package manager (Installation Guide)

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License

MIT License - See LICENSE