Unity CLI

Install and use unity-mcp-cli to call the engine's MCP tools from a terminal.

Prerequisites

Node.js ^20.19.0 or >=22.12.0 and npm are required. Node.js 21 is unsupported. Check existing installations first:

node --version
npm.cmd --version

If needed, install a supported Node.js LTS release from https://nodejs.org/ and reopen the terminal. Use the Windows installer and reopen PowerShell. The examples use .cmd launchers to avoid npm PowerShell execution-policy restrictions.

Install and verify

npm.cmd install -g unity-mcp-cli
unity-mcp-cli.cmd --version
unity-mcp-cli.cmd --help

Alternatively, use npm's temporary runner without a global installation:

npx.cmd unity-mcp-cli --help

Replace the leading unity-mcp-cli.cmd with npx.cmd unity-mcp-cli in subsequent examples when using this option.

Call tools

Run commands from the game project's root directory. The target editor or game must be running with its MCP plugin connected. The following read-only example lists the available RQL sources and types in the editor:

unity-mcp-cli.cmd status
unity-mcp-cli.cmd run-tool rql-schema --input '{}'

For input files, create a UTF-8 JSON file and pass its path. This example makes the same read-only call:

[System.IO.File]::WriteAllText((Join-Path $PWD 'args.json'), '{}')
unity-mcp-cli.cmd run-tool rql-schema --input-file args.json

Replace rql-schema and the JSON with the tool name and arguments from its individual skill. Use command-specific --help for options. RQL tools require an editor; a game exposes only its registered runtime tools.

Troubleshooting

• node or npm.cmd not found: finish installing Node.js, check PATH, and reopen the terminal.
• unity-mcp-cli.cmd not found: reopen the terminal, check the npm global executable directory in PATH, or use npx.cmd unity-mcp-cli.
• Global npm installation denied: use a user-owned Node.js installation or the npx alternative.
• Connection unavailable: check the project directory and ensure its editor or game and MCP plugin are running and connected.

For optional asset-generation and Blender workflows, consult the ai-game-dev-app skill.