unity-mcp-server

<p align="center"> <img src="icon.png" alt="AnkleBreaker MCP" width="180" /> </p> # Unity MCP Server — AI-Powered Unity Editor & Hub Control > **The most comprehensive [Model Context Protocol (MCP)](https://modelcontextprotocol.io) server for Unity game development.** Connect Claude, Cursor, Windsurf, or any MCP-compatible AI assistant to **Unity Editor** and **Unity Hub** with **288 tools** across **30+ categories**. Built and maintained by [AnkleBreaker Studio](https://github.com/AnkleBreaker-Studio). **AnkleBreaker Unity MCP** turns your AI assistant into a full Unity co-pilot — create scenes, manipulate GameObjects, manage components, run builds, profile performance, edit Shader Graphs, control Amplify Shader Editor, sculpt terrain, bake NavMesh, manage animations, run multiplayer playmode scenarios, and much more — all without leaving your AI chat. Works with Claude Desktop, Claude Cowork, Cursor, Windsurf, and any tool that supports the Model Context Protocol. ### Neon Brick Breaker — Built from scratch by AI in under 5 minutes > Claude creates the entire game: scene setup, neon materials with bloom post-processing, brick grid layout, game scripts, VFX, and UI — all through Unity MCP commands. <p align="center"> <img src="docs/unity-mcp-showcase-brickbreaker.gif" alt="Unity MCP — AI building a neon brick breaker game in Unity Editor" width="800" /> </p> ### 3D Medieval Village — AI-generated terrain, houses, and environment > From an empty scene to a fully decorated village: terrain sculpting, material creation, procedural house building via C# editor scripts, trees, fences, and pathways. <p align="center"> <img src="docs/unity-mcp-showcase-village.gif" alt="Unity MCP — AI building a 3D medieval village with houses, trees, and terrain" width="800" /> </p> ### 3D Castle — Complete level with FPS walkthrough > AI builds a multi-room castle with courtyard, throne room, armory, and guard room. Adjusts lighting, spawns the player, and runs an FPS walkthrough to verify the result. <p align="center"> <img src="docs/unity-mcp-showcase-castle.gif" alt="Unity MCP — AI building a 3D castle with FPS walkthrough in Unity Editor" width="800" /> </p> ### How It Works — AI → MCP Server → Unity Plugin → Unity Editor > The Model Context Protocol connects your AI assistant to Unity through a lightweight bridge. Commands flow from your AI chat directly into the editor in real-time. <p align="center"> <img src="docs/unity-mcp-architecture.gif" alt="Unity MCP Architecture — AI Assistant → MCP Server → Unity Plugin → Unity Editor" width="800" /> </p> ## Features **288 tools** covering the full Unity workflow: | Category | Tools | |----------|-------| | **Unity Hub** | List/install editors, manage modules, set install paths | | **Scenes** | Open, save, create scenes, get full hierarchy tree with pagination | | **GameObjects** | Create (primitives/empty), delete, duplicate, reparent, activate/deactivate, transform (world/local) | | **Components** | Add, remove, get/set any serialized property, wire object references, batch wire | | **Assets** | List, import, delete, search, create prefabs, create & assign materials | | **Scripts** | Create, read, update C# scripts | | **Builds** | Multi-platform builds (Windows, macOS, Linux, Android, iOS, WebGL) | | **Console & Compilation** | Read/clear Unity console logs (errors, warnings, info); get C# compilation errors via CompilationPipeline (independent of console buffer) | | **Testing** | Run EditMode/PlayMode tests, poll results, list available tests via Unity Test Runner API | | **Play Mode** | Play, pause, stop | | **Editor** | Execute menu items, run C# code, get editor state, undo/redo | | **Project** | Project info, packages (list/add/remove/search), render pipeline, build settings | | **Animation** | List clips & controllers, get parameters, play animations | | **Prefab** | Open/close prefab mode, get overrides, apply/revert changes | | **Physics** | Raycasts, sphere/box casts, overlap tests, physics settings | | **Lighting** | Manage lights, environment, skybox, lightmap baking, reflection probes | | **Audio** | AudioSources, AudioListeners, AudioMixers, play/stop, mixer params | | **Terrain** | Create/modify terrains, paint heightmaps/textures, manage terrain layers, trees, details | | **Navigation** | NavMesh baking, agents, obstacles, off-mesh links | | **Particles** | Particle system creation, inspection, module editing | | **UI** | Canvas, UI elements, layout groups, event system | | **Tags & Layers** | List/add/remove tags, assign tags & layers | | **Selection** | Get/set editor selection, find by name/tag/component/layer/tag | | **Graphics** | Scene and game view capture (inline images for visual inspection) | | **Input Actions** | Action maps, actions, bindings (Input System package) | | **Assembly Defs** | List, inspect, create, update .asmdef files | | **ScriptableObjects** | Create, inspect, modify ScriptableObject assets | | **Constraints** | Position, rotation, scale, aim, parent constraints | | **LOD** | LOD group management and configuration | | **Profiler** | Start/stop profiling, stats, deep profiles, save profiler data | | **Frame Debugger** | Enable/disable, draw call list & details, render targets | | **Memory Profiler** | Memory breakdown, top consumers, snapshots (`com.unity.memoryprofiler`) | | **Shader Graph** | List, inspect, create, open Shader Graphs & Sub Graphs; VFX Graphs | | **Amplify Shader Editor** | Full graph manipulation — create, inspect, add/remove/connect/disconnect/duplicate nodes, set properties, templates, save/close (if installed) | | **MPPM Scenarios** | List, activate, start, stop multiplayer playmode scenarios; get status & player info | | **Multi-Instance** | Discover and switch between multiple running Unity Editor instances | | **Multi-Agent** | List active agents, get agent action logs, queue monitoring | | **SpriteAtlas** | Create, inspect, add/remove sprites, configure settings, delete, list SpriteAtlases | | **UMA (Unity Multipurpose Avatar)** | Create slots, overlays, wardrobe recipes from FBX; equip/unequip items on DCA; browse/rebuild Global Library | | **Project Context** | Auto-inject project-specific docs and guidelines for AI agents | ## Architecture ``` Claude / AI Assistant ←→ MCP Server (this repo) ←→ Unity Editor Plugin (HTTP bridge) ↕ Unity Hub CLI ``` This server communicates with: - **Unity Hub** via its CLI (supports both modern `--headless` and legacy `-- --headless` syntax) - **Unity Editor** via the companion [unity-mcp-plugin](https://github.com/AnkleBreaker-Studio/unity-mcp-plugin) which runs an HTTP API inside the editor ### 288 Tools Across 30+ Categories > Scene management, GameObjects, components, physics, terrain, Shader Graph, Amplify Shader Editor, profiling, animation, NavMesh, builds, multiplayer, and more. <p align="center"> <img src="docs/unity-mcp-features.gif" alt="Unity MCP Features — 268 tools across 30+ categories for AI-powered game development" width="800" /> </p> ### Two-Tier Tool System To avoid overwhelming MCP clients with 288 tools, the server uses a two-tier architecture: - **Core tools** (~70) are always exposed directly - **Advanced tools** (~130+) are accessed via a single `unity_advanced_tool` proxy with lazy loading This keeps the tool count manageable for clients like Claude Desktop and Cowork while still providing access to every Unity feature. Use `unity_list_advanced_tools` to discover all advanced tools by category. ### Multi-Instance Support The server automatically discovers all running Unity Editor instances on startup. If only one instance is found, it auto-connects. If multiple instances are running (e.g., main editor + ParrelSync clones), it prompts you to select which one to work with. **Port Resilience** — The server includes a multi-layer protection system for reliable multi-project workflows: - **Port Identity Validation** — When restoring a saved connection, the server verifies the instance identity (project name + path) matches the expected target. If Unity restarts and a different project grabs the port, the server detects this and re-discovers the correct instance. - **Compile-Time Resilience** — During long Unity compiles (when the editor is unresponsive), the server checks the shared instance registry. If the registry entry is fresh (updated within the last 5 minutes via heartbeat), the connection is preserved instead of dropped. - **Crash Detection** — The plugin sends a heartbeat every 30 seconds to the instance registry. If Unity crashes and the heartbeat stops, the server detects the stale registry entry (>5 minutes old) and clears it, allowing proper re-discovery. - **Port Affinity** — The plugin remembers its last-used port via EditorPrefs and reclaims it on restart, minimizing port swaps across editor restarts. ## Quick Start ### 1. Install the Unity Plugin In Unity: **Window > Package Manager > + > Add package from git URL:** ``` https://github.com/AnkleBreaker-Studio/unity-mcp-plugin.git ``` ### 2. Install this MCP Server ```bash git clone https://github.com/AnkleBreaker-Studio/unity-mcp-server.git cd unity-mcp-server npm install ``` ### 3. Add to Claude Desktop Open Claude Desktop > Settings > Developer > Edit Config, and add: ```json { "mcpServers": { "unity": { "command": "node", "args": ["C:/path/to/unity-mcp-server/src/index.js"], "env": { "UNITY_HUB_PATH": "C:\\Program Files\\Unity Hub\\Unity Hub.exe", "UNITY_BRIDGE_PORT": "7890" } } } } ``` Restart Claude Desktop. Done! ### 4. Try It - *"List my installed Unity editors"* - *"Show me the scene hierarchy"* - *"Create a red cube at position (0, 2, 0) and add a Rigidbody"* - *"Profile my scene and show the top memory consumers"* - *"List all Shader Graphs in my project"* - *"Build my project for Windows"* - *"List and start my MPPM multiplayer scenarios"* - *"Capture a screenshot of my scene view"* - *"Show me the active agent sessions"* ## Configuration | Environment Variable | Default | Description | |---------------------|---------|-------------| | `UNITY_HUB_PATH` | `C:\Program Files\Unity Hub\Unity Hub.exe` | Unity Hub executable path | | `UNITY_BRIDGE_HOST` | `127.0.0.1` | Editor bridge host | | `UNITY_BRIDGE_PORT` | `7890` | Editor bridge port (auto-discovered when using multi-instance) | | `UNITY_BRIDGE_TIMEOUT` | `30000` | Request timeout in ms | | `UNITY_PORT_RANGE_START` | `7890` | Start of port scan range for multi-instance discovery | | `UNITY_PORT_RANGE_END` | `7899` | End of port scan range | | `UNITY_REGISTRY_STALENESS_TIMEOUT` | `300000` | Registry entry staleness timeout in ms (crash detection) | | `UNITY_RESPONSE_SOFT_LIMIT` | `2097152` | Response size soft limit in bytes (warning) | | `UNITY_RESPONSE_HARD_LIMIT` | `4194304` | Response size hard limit in bytes (truncation) | | `UNITY_MCP_DEBUG` | `false` | Enable debug logging for troubleshooting | The Unity plugin also has its own settings accessible via the Dashboard (`Window > MCP Dashboard`) for port, auto-start, and per-category feature toggles. ## Optional Package Support Some tools activate automatically when their packages are detected in the Unity project: | Package / Asset | Features Unlocked | |----------------|-------------------| | `com.unity.memoryprofiler` | Memory snapshot capture via MemoryProfiler API | | `com.unity.shadergraph` | Shader Graph creation, inspection, opening | | `com.unity.visualeffectgraph` | VFX Graph listing and opening | | `com.unity.inputsystem` | Input Action map and binding inspection | | `com.unity.multiplayer.playmode` | MPPM scenario listing, activation, start/stop, player info | | Amplify Shader Editor (Asset Store) | Amplify shader listing, inspection, opening | | UMA 2 (Asset Store) | UMA SlotDataAsset/OverlayDataAsset creation, WardrobeRecipe pipeline, Global Library management, DCA wardrobe equip/unequip | Features for uninstalled packages return helpful messages explaining what to install. ## Requirements - Node.js 18+ - Unity Hub (for Hub tools) - Unity Editor with [unity-mcp-plugin](https://github.com/AnkleBreaker-Studio/unity-mcp-plugin) installed (for Editor tools) ## Troubleshooting **"Connection failed" errors** — Make sure Unity Editor is open and the plugin is installed. Check the Unity Console for `[MCP Bridge] Server started on port 7890`. **"Unity Hub not found"** — Update `UNITY_HUB_PATH` in your config to match your installation. **"Category disabled" errors** — A feature category may be toggled off. Open `Window > MCP Dashboard` in Unity to check category settings. **Port conflicts** — Change `UNITY_BRIDGE_PORT` in your Claude config and update the port in Unity's MCP Dashboard settings. ## Why AnkleBreaker Unity MCP? AnkleBreaker Unity MCP is the most comprehensive MCP integration for Unity, purpose-built to leverage the full power of **Claude Cowork** and other AI assistants. Here's how it compares to alternatives: ### Feature Comparison | Feature | **AnkleBreaker MCP** | **Bezi** | **Coplay MCP** | **Unity AI** | |---------|:-------------------:|:--------:|:--------------:|:------------:| | **Total Tools** | **288** | ~30 | 34 | Limited (built-in) | | **Feature Categories** | **30+** | ~5 | ~5 | N/A | | **Non-Blocking Editor** | ✅ Full background operation | ❌ Freezes Unity during tasks | ✅ | ✅ | | **Open Source** | ✅ AnkleBreaker Open License | ❌ Proprietary | ✅ MIT License | ❌ Proprietary | | **Claude Cowork Optimized** | ✅ Two-tier lazy loading | ❌ Not MCP-based | ⚠️ Basic | ❌ Not MCP-based | | **Multi-Instance Support** | ✅ Auto-discovery | ❌ | ❌ | ❌ | | **Multi-Agent Support** | ✅ Session tracking + queuing | ❌ | ❌ | ❌ | | **Unity Hub Control** | ✅ Install editors & modules | ❌ | ❌ | ❌ | | **Scene Hierarchy** | ✅ Full tree + pagination | ⚠️ Limited | ⚠️ Basic | ⚠️ Limited | | **Physics Tools** | ✅ Raycasts, overlap, settings | ❌ | ❌ | ❌ | | **Terrain Tools** | ✅ Full terrain pipeline | ❌ | ❌ | ❌ | | **Shader Graph** | ✅ Create, inspect, open | ❌ | ❌ | ❌ | | **Profiling & Debugging** | ✅ Profiler + Frame Debugger + Memory | ❌ | ❌ | ⚠️ Basic | | **Animation System** | ✅ Controllers, clips, parameters | ⚠️ Basic | ⚠️ Basic | ⚠️ Basic | | **NavMesh / Navigation** | ✅ Bake, agents, obstacles | ❌ | ❌ | ❌ | | **Particle Systems** | ✅ Full module editing | ❌ | ❌ | ❌ | | **MPPM Multiplayer** | ✅ Scenarios, start/stop | ❌ | ❌ | ❌ | | **Visual Inspection** | ✅ Scene + Game view capture | ❌ | ⚠️ Limited | ❌ | | **Play Mode Resilient** | ✅ Survives domain reload | ❌ | ❌ | N/A | | **Port Resilience** | ✅ Identity validation + crash detection | ❌ | ❌ | N/A | | **Project Context** | ✅ Custom docs for AI agents | ❌ | ❌ | ⚠️ Built-in only | ### Cost Comparison > **AnkleBreaker Unity MCP is completely free and open source.** The prices below reflect only the cost of the AI assistant (Claude) itself — the MCP plugin and server are $0. | Solution | Monthly Cost | What You Get | |----------|:----------:|--------------| | **AnkleBreaker MCP (free) + Claude Pro** | **$20/mo** | 288 tools, full Unity control, open source — MCP is free, price is Claude only | | **AnkleBreaker MCP (free) + Claude Max 5x** | **$100/mo** | Same + 5x usage for heavy workflows — MCP is free, price is Claude only | | **AnkleBreaker MCP (free) + Claude Max 20x** | **$200/mo** | Same + 20x usage for teams/studios — MCP is free, price is Claude only | | **Bezi Pro** | $20/mo | ~30 tools, 800 credits/mo, freezes Unity | | **Bezi Advanced** | $60/mo | ~30 tools, 2400 credits/mo, freezes Unity | | **Bezi Team** | $200/mo | 3 seats, 8000 credits, still freezes Unity | | **Unity AI** | Included with Unity Pro/Enterprise | Limited AI tools, Unity Points system, no MCP | | **Coplay MCP** | Free (beta) | 34 tools, basic categories | ### Key Advantages **vs. Bezi:** Bezi runs as a proprietary Unity plugin with its own credit-based billing — $20–$200/mo on top of your AI subscription. It has historically suffered from freezing the Unity Editor during AI tasks, blocking your workflow. AnkleBreaker MCP is completely free and open source, runs entirely in the background with zero editor impact, and offers 8x more tools — the only cost is your existing Claude subscription. **vs. Coplay MCP:** Coplay MCP provides 34 tools across ~5 categories. AnkleBreaker MCP delivers 288 tools across 30+ categories including advanced features like physics raycasts, terrain editing, shader graph management, profiling, NavMesh, particle systems, and MPPM multiplayer — none of which exist in Coplay. Our two-tier lazy loading system is specifically optimized for Claude Cowork's tool limits. **vs. Unity AI:** Unity AI (successor to Muse) is built into Unity 6.2+ but limited to Unity's own AI models and a credit-based "Unity Points" system. It cannot be used with Claude or any external AI assistant, has no MCP support, and offers a fraction of the automation capabilities. AnkleBreaker MCP works with any MCP-compatible AI while giving you full control over which AI models you use. ## Support the Project If Unity MCP helps your workflow, consider supporting its development! Your support helps fund new features, bug fixes, documentation, and more open-source game dev tools. <a href="https://github.com/sponsors/AnkleBreaker-Studio"> <img src="https://img.shields.io/badge/Sponsor-GitHub%20Sponsors-ea4aaa?logo=github&style=for-the-badge" alt="GitHub Sponsors" /> </a> <a href="https://www.patreon.com/AnkleBreakerStudio"> <img src="https://img.shields.io/badge/Support-Patreon-f96854?logo=patreon&style=for-the-badge" alt="Patreon" /> </a> **Sponsor tiers include priority feature requests** — your ideas get bumped up the roadmap! Check out the tiers on [GitHub Sponsors](https://github.com/sponsors/AnkleBreaker-Studio) or [Patreon](https://www.patreon.com/AnkleBreakerStudio). ## What's New in v2.28.0 - **npm auto-publish** — A GitHub Action now automatically publishes to npm whenever a new GitHub release is created. Contributed by [@vatanaksoytezer](https://github.com/vatanaksoytezer) in [#8](https://github.com/AnkleBreaker-Studio/unity-mcp-server/pull/8). - **npm package renamed** — Package renamed from `unity-mcp-server` to `anklebreaker-unity-mcp` to avoid name conflict on npm. Install via `npx anklebreaker-unity-mcp@latest`. - **SpriteAtlas tools** — 7 new tools for Unity SpriteAtlas management: create, inspect, add/remove sprites, configure packing & texture settings, delete, and list SpriteAtlases. Contributed by [@zaferdace](https://github.com/zaferdace). Registered as advanced tools accessible via `unity_advanced_tool`. - **UTF-8 encoding fix** — Fixed corrupted characters in `unity-editor-bridge.js` comments and section headers. ## What's New in v2.27.0 - **UMA (Unity Multipurpose Avatar) integration** — 13 new tools for the complete UMA asset pipeline. Create SlotDataAssets, OverlayDataAssets, and WardrobeRecipes directly from FBX files, equip/unequip wardrobe items on DynamicCharacterAvatar, browse and manage the UMA Global Library, verify recipes for missing references, and more. Requires UMA 2 (available on the Asset Store). Registered as advanced tools accessible via `unity_advanced_tool`. ## What's New in v2.26.0 - **Compilation error detection** — New `unity_get_compilation_errors` tool retrieves C# compilation errors and warnings directly from Unity's `CompilationPipeline` API. Unlike `unity_console_log`, this is independent of the console log buffer — not affected by console clear, Play Mode log flooding, or buffer overflow. Supports filtering by severity (`error`, `warning`, `all`) and count limit. Registered as a core tool (always directly accessible, not behind `unity_advanced_tool`). ## What's New in v2.25.0 - **Parallel-safe instance routing** — When multiple AI agents (e.g. Claude Cowork tasks) share the same MCP process, each agent can now include a `port` parameter in every `unity_*` tool call to guarantee routing to the correct Unity Editor instance. This prevents cross-agent contamination where one task's `unity_select_instance` could redirect another task's commands to the wrong project. - **Per-request port override** — A new stateless routing mechanism bypasses the shared per-agent state entirely. The `port` parameter is extracted by middleware before the tool handler runs, used for routing, then stripped from the args. This is safe because MCP stdio transport processes requests sequentially. - **Schema injection** — The optional `port` parameter is automatically injected into every `unity_*` tool schema (except `unity_list_instances`, `unity_select_instance`, and `unity_hub_*`), so AI assistants see it as a legitimate parameter and pass it consistently. - **Enhanced select_instance response** — `unity_select_instance` now returns explicit routing instructions telling the AI to include `port` in all subsequent calls. ## Frequently Asked Questions **What is Unity MCP?** Unity MCP (Model Context Protocol) is an open-source integration that connects AI assistants like Claude, Cursor, and Windsurf to the Unity Editor and Unity Hub. It allows AI to directly control Unity — creating scenes, placing objects, writing scripts, running builds, profiling, and more — through a standardized protocol. **How does AnkleBreaker Unity MCP compare to other Unity AI tools?** AnkleBreaker Unity MCP offers 288 tools across 30+ categories, making it the most comprehensive Unity MCP integration available. Competitors like Bezi (~30 tools) and Coplay MCP (34 tools) cover a fraction of Unity's features. Unlike Bezi, AnkleBreaker MCP is free, open source, and doesn't freeze the Unity Editor during AI operations. **Does it work with Claude Desktop / Claude Cowork?** Yes. AnkleBreaker Unity MCP is purpose-built for Claude Desktop and Claude Cowork. It uses a two-tier lazy loading system to stay within MCP client tool limits while exposing all 281 tools on demand. **Does it work with Cursor, Windsurf, or other MCP clients?** Yes. Any AI tool that supports the Model Context Protocol can connect to this server. This includes Cursor, Windsurf, Claude Desktop, Claude Cowork, and any other MCP-compatible client. **What Unity versions are supported?** Unity 2021.3 LTS and newer, including Unity 2022.3 LTS and Unity 6. The plugin is installed via Unity Package Manager (UPM). **Is it free?** Yes. Both the MCP server and the Unity plugin are completely free and open source under the AnkleBreaker Open License. The only cost is your AI assistant subscription (e.g., Claude Pro at $20/month). **Can multiple AI agents use it simultaneously?** Yes. The server supports multi-agent operation with session tracking, action logging, and queued execution to prevent conflicts. It also supports multiple Unity Editor instances running side-by-side. **Does it support Amplify Shader Editor?** Yes. If Amplify Shader Editor is installed in your project, 23 additional tools are unlocked for full shader graph manipulation — creating nodes, connecting them, setting properties, using templates, and more. Projects without Amplify work perfectly; the tools gracefully report that ASE is not installed. ## Related Projects - **[unity-mcp-plugin](https://github.com/AnkleBreaker-Studio/unity-mcp-plugin)** — The companion Unity Editor plugin (UPM package) that this server connects to - **[Model Context Protocol](https://modelcontextprotocol.io)** — The open standard that powers this integration - **[Claude Desktop](https://claude.ai/download)** — Anthropic's AI assistant with built-in MCP support - **[AnkleBreaker Studio](https://github.com/AnkleBreaker-Studio)** — The game studio behind this project --- <details> <summary><strong>Keywords</strong> (for search engines)</summary> Unity MCP, Unity MCP Server, Unity MCP Plugin, Unity AI, AI game development, AI Unity Editor, Claude Unity, Cursor Unity, Windsurf Unity, Model Context Protocol Unity, MCP server Unity, Unity automation, AI-assisted game development, Unity Editor AI control, Unity Hub AI, Unity build automation, Unity scene management AI, Unity GameObject AI, Unity component automation, Shader Graph AI, Amplify Shader Editor AI, Unity terrain AI, Unity NavMesh AI, Unity physics AI, Unity profiler AI, Unity animation AI, MPPM multiplayer AI, Unity MCP integration, free Unity AI tools, open source Unity AI, AnkleBreaker Studio, AnkleBreaker MCP, Unity MCP bridge, Unity Editor plugin MCP, UPM MCP package, AI co-pilot Unity, Unity game dev AI assistant </details> ## License AnkleBreaker Open License v1.0 — see [LICENSE](LICENSE) This license requires: (1) including the copyright notice, (2) displaying **"Made with AnkleBreaker MCP"** (or "Powered by AnkleBreaker MCP") attribution in any product built with it (personal/educational use is exempt), and (3) **reselling the tool is forbidden** — you may not sell, sublicense, or commercially distribute this software or derivatives of it. See the full [LICENSE](LICENSE) for details.