Unity Open MCP

Unity Open MCP is one of the broadest open-source MCP implementations for Unity, with 270+ typed tools in a production-oriented automation stack. Safety-gated mutations, built-in validation, and live, headless, and offline execution support reliable work on real projects—from asset intelligence and editor authoring to closed-loop game testing, diagnostics, CI, and package-gated Unity domains.

Edit GameObjects, scenes, prefabs, materials, packages, and package-gated domains such as NavMesh, Input System, Cinemachine, Timeline, and Shader Graph. Mutations run checkpoint → mutate → validate → delta, with regression checks and targeted fixes.

User: Remove that prefab.
Agent: The gate preview found new missing references in Level1 and SpawnPoint, so I stopped before committing a broken project.

Run Edit/Play Mode tests, inspect the console, capture screenshots, profiler and memory data, and pull events. Input simulation closes the gameplay loop: probe interactables, click / drag / swipe, advance frames, then verify visually.

Prefer the live Editor, fall back to an exact-version headless Editor for supported tools, and read assets or compile diagnostics from disk when Unity is closed. Structured search, reserialization, and reference / dependency analysis remain available where their route supports it.

Unity projects can expose typed, discoverable commands without an MCP server release. Explicitly async operations run as observable jobs with progress, idempotency, retained results, and truthful cancellation. The CLI and CI flows add health checks, verify baselines, and regression gates.

See Project commands and Asynchronous jobs.

Only core and gate-and-verify are visible by default; activate the other domains on demand. Runtime capabilities provide exact schemas, routes, and availability, while project skills teach agents the mutate → gate → fix loop.

One command installs matching package pins, MCP configuration, and the agent skill. Team and monorepo layouts default to committable, machine-independent configuration. Coordinated update flows cover the MCP server, Unity packages, and the optional Unity Hub Pro desktop app.

More example prompts: docs/api/mcp-tools.md. Full catalog and contracts: docs/api/mcp-tools.md.

Requires Unity 2022.3 LTS or newer and Node.js 18+ for the MCP server.

1. CLI — recommended: open a terminal in the Unity project and run:

   npx -y unity-open-mcp@latest setup --client cursor

   Use claude, zcode, vscode, codex, opencode, or agents for another supported writer. The command installs matching pins, project config, and the bundled skill; see Manual setup for details.

2. Unity Hub Pro: use the graphical flow in Wizard setup.

3. Manual: copy the package and client configuration yourself from MCP client configuration.

4. Local checkout: build and run the repository with Development setup.

5. Experimental — AI agent: paste the prompt below into your AI client.

Install Unity Open MCP in this Unity project by following
https://raw.githubusercontent.com/AlexeyPerov/Unity-Open-MCP/master/docs/setup/agent-setup.md
exactly (fetch it fresh; do not improvise from memory).
Resolve this project's absolute Unity root and my client, then run
npx -y unity-open-mcp@latest setup --project <absolute-project> --client <id>.
Let that package choose all version pins and copy its bundled SKILL.md; do not
invent versions, rewrite the skill, or call generate_skill. Do every agent step
yourself and stop only when human action is required. If this monorepo is already
open locally, read docs/setup/agent-setup.md from disk instead of fetching it.

Full procedure: Agent setup. For teams and monorepos, use a portable MCP configuration that can be committed without per-developer absolute paths.

For users:

• API index — MCP, bridge, resource, routing, and automation contracts.
• Extensions — embedded domains, dependencies, and tool-group activation.
• Troubleshooting — connectivity and recovery guidance.
• Dialog policy — startup modal handling and automation.
• Skills — agent playbooks installed into Unity projects.
• Version compatibility — version matching and mismatch recovery.
• Updating — Hub, MCP, Unity package, and air-gapped update paths.

For contributors:

• Architecture — repository boundaries and runtime flow.
• Code conventions — non-obvious C# contracts.

Would like to see other MCP options? See the MCP tools for Unity comparison — a side-by-side feature matrix of Unity Open MCP and the other MCP tools / AI assistants in the space.

• Read CONTRIBUTING.md before opening an issue or pull request.
• Contributor troubleshooting covers local test, bridge, and automation failures.
• Maintainer versioning and releases — synchronization, tags, and release workflows.

License: MIT — see LICENSE.