Unity MCP — 718 Tools for AI-Powered Game Development
MCP (Model Context Protocol) server that connects Claude Code (or any MCP client) directly to the Unity Editor. Control every aspect of Unity — scenes, assets, materials, physics, lighting, animation, UI, and more — through natural language.
Free. Open-source. Full codebase access. No API key required.
What Can You Do?
Just talk to Claude Code in plain English (or any language):
- "Create a first-person controller with mouse look and WASD movement"
- "Add a directional light, skybox fog, and bake lighting for this scene"
- "Generate a tile palette from these sprites and paint a 20x20 dungeon"
- "Capture a screenshot of the Inspector and tell me what's wrong with my Rigidbody setup"
- "Find all missing script references and list them"
- "Create a Cinemachine virtual camera that follows the player with smooth damping"
Claude reads your scene, edits components, creates scripts, bakes lighting, runs tests, captures screenshots — all while you focus on design decisions.
Quick Start
# In your Unity project root:
npx github:karnelian/unity-mcp setup
This single command:
- Installs the Unity Editor plugin to
Assets/KarnelLabsMCP/Editor/
- Adds Unity's official
com.unity.nuget.newtonsoft-json package to Packages/manifest.json when missing — this uses Unity Package Manager and does not require a separate nuget CLI install
- Installs a Unity 6000.5+ compatibility layer for
GetEntityId, missing-reference checks, and non-deprecated FindObjectsByType overloads
- Creates
.mcp.json for Claude Code auto-connection
Then:
- Open the project in Unity
- Wait for compilation → Tools > KarnelLabs MCP > Server Window
- Open Claude Code in the same folder and start building!
KarnelLabs MCP Server Window
Once installed, open the server window via Tools > KarnelLabs MCP > Server Window. You should see:
The window shows:
- Connection Status —
Connected (active socket), Recently Active (Claude made a recent MCP call), Listening, or Stopped
- Handlers — number of registered C# command handlers (686+)
- Server Settings — WebSocket port (default 8099), Start/Stop/Restart
- Claude Code Configuration — copy-paste JSON for
.mcp.json / claude_desktop_config.json
- Recent Requests — last 20 MCP calls for debugging
- Info — Unity version, project name, WebSocket URL
Commands
Claude Code Marketplace Install
This repository ships a Claude Code plugin marketplace entry. After the marketplace files are merged to GitHub, install it with:
gh auth login
claude plugin marketplace add karnelian/unity-mcp
claude plugin install unity-mcp@karnelian-unity-mcp -s user
The marketplace plugin starts the optimized MCP server automatically with the default core profile. Each Unity project still needs the Unity package setup once from the project root:
npx -y github:karnelian/unity-mcp setup --profile=core
For UI-heavy Unity projects:
npx -y github:karnelian/unity-mcp setup --profile=core,ui
After install/update, restart Claude Code so plugin MCP servers reload.
npx github:karnelian/unity-mcp setup # First-time install (plugin + .mcp.json, default profile: core)
npx github:karnelian/unity-mcp setup --profile=core,ui # Install/update .mcp.json with UI tools enabled
npx github:karnelian/unity-mcp update # Update plugin only (keeps .mcp.json)
npx github:karnelian/unity-mcp instances # List running Unity instances
Tool Profiles
By default the MCP server exposes the lightweight core profile instead of all 74 tool categories. This keeps Claude Code's tool list smaller, cheaper, and less confusing. The installed package is the same; profiles only choose which tool groups are registered for the current MCP session.
npx github:karnelian/unity-mcp --profile=core,ui
npx github:karnelian/unity-mcp --profile=core,2d
npx github:karnelian/unity-mcp --profile=core,xr,rendering
npx github:karnelian/unity-mcp --profile=full
Common profiles:
