Kiro Unity Accelerator

Note on language availability: README files are available in 5 languages to support our global community. Examples and demo steps are intentionally parallel across all language versions for consistency — each version is human-reviewed for natural phrasing in that language. Steering files (domain knowledge) are in Traditional Chinese with English summary sections at the top of each file. The Power responds in the developer's preferred language, even though steering files are in Traditional Chinese with English summaries. If you encounter any language barriers, please open an issue for community support.

Transform your IDE into a Unity development AI assistant. Use natural language to command Unity Editor via MCP (Model Context Protocol — a standardized way for AI assistants to interact with development tools, allowing developers to describe what they want in plain language instead of manually navigating menus or writing boilerplate scripts). This Power covers asset management, scene building, build automation, performance analysis, code quality checks, and more — with 40+ TypeScript tool modules and 15 domain knowledge files.

Unity 6.4 baseline: This Power targets Unity 6.4 (release stream 6000.4, newest patch 6000.4.12f1, released 17 Jun 2026) and the tool surface of MCP for Unity v10.3.0 or newer (minimum v10.0.0). The minimum Editor for this Power is Unity 6.0 (6000.0); the bridge's own floor is lower (Unity 2021.3 LTS). The guidance was live-checked against Unity 6000.4.6f1 + URP 17.4.0 + MCP for Unity 9.6.8, Windows Editor, 2026-10-21 — Unity 6.5, 6.6 and later 6.x are expected to work but were not verified here. Unity 6.4 is an Update release and its patch stream ended 17 Jun 2026, so a project locking down for production should move to Unity 6.3 LTS (supported through Dec 2027) or forward onto the current Update release. Unity 6.0 LTS support ended 16 Oct 2026 — it is never recommended, not even as a "safe older version". Sources: unity.com/releases and endoflife.date/unity, both retrieved 2026-10-21.

What the 6.4-specific guidance covers: URP Render Graph is the only path — URP Compatibility Mode and the URP_COMPATIBILITY_MODE scripting define were removed in 6.4, so it is no longer an escape hatch for legacy custom render passes; the GPU Resident Drawer (Forward+/Deferred+ GPU instancing, unavailable on the 2D Renderer) together with the redesigned Rendering Statistics window, which itemises which batching path absorbed each draw call instead of reporting one number; InstanceID deprecated in favour of EntityId, so an instance id returned by the bridge is an opaque token — pass it straight back, never do arithmetic on it, sort by it, or parse it; PVRTC removed on iOS (ASTC or ETC only); Web builds running [BurstCompile] jobs on background workers even though multithreaded rendering is still unavailable; a custom render pass can now be injected into the URP 2D frame loop; and the OculusXR package is deprecated in favour of the OpenXR plug-in, with HoloLens 2 support and its plug-in deprecated in 6.4 (the OculusXR removal release is unverified). Scripting backend: manage_build accepts mono or il2cpp only — CoreCLR cannot be selected through this Power. Sources: New in Unity 6.4 and Upgrade to Unity 6.4, both retrieved 2026-10-21.

Rather than trusting a remembered version number, the Power checks the connected project through MCP — manage_graphics(action: "pipeline_get_info") for the active render pipeline, the mcpforunity://project/info resource for the Unity version and platform, and manage_packages(action: "list_packages") for installed packages — before applying any version-specific advice.

Key Concepts: Technical terms used throughout this document (if you are new to Unity development, these concepts will become clearer as you work through the examples — you do not need to understand them all upfront):

MCP (Model Context Protocol): A standardized protocol for AI assistants to communicate with development tools, enabling developers to use natural language to operate Unity Editor

DAG (Directed Acyclic Graph): A directed graph with no cycles, used to determine task dependency order (e.g., "import textures before creating materials")

MVC (Model-View-Controller): An architecture pattern that separates code into data (Model), display (View), and logic (Controller)

ECS (Entity-Component-System): Unity DOTS data-oriented architecture pattern for efficiently processing large numbers of objects (e.g., managing thousands of entities simultaneously)

ScriptableObject: Unity's serializable data container for storing configuration and shared data (without needing to attach to scene objects)

AssetBundle: Unity's asset packaging format for distribution and dynamic loading (reduces initial install size)

Features

Asset Automation — Batch apply asset presets, auto-detect asset types, generate change summaries
Scene Scaffolding — One-command scene structure generation with conflict detection
Build Automation — Local builds through manage_build, build log parsing, reusable build configuration templates
Cross-Platform Testing — Test execution through run_tests / get_test_job, result formatting, test suite conversion
Workflow Automation — Multi-step workflows with DAG dependency validation and topological execution
Performance Analysis — Profiler screenshot analysis, code anti-pattern scanning, optimization recommendations
Code Quality — MVC/ECS/ScriptableObject architecture checks, circular dependency detection
Knowledge Management — Team documentation management, API change tracking, staleness detection
Platform Compatibility — Shader compatibility, memory budget checks, severity classification (including XR/VR)
Asset Dependency Management — Dependency trees, orphan asset detection, AssetBundle duplication checks
Level Design Tooling — Editor extension script generation, ScriptableObject templates, batch scene object configuration
UI Dependency Analysis — Cross-file UI reference tracking, event chain analysis, coupling assessment

Architecture

Developer (Natural Language)
    → AI Layer (Intent Understanding & Planning)
        → MCP Protocol
            → Unity Editor (Execution Layer)

Unity Accelerator (Intelligence Layer)
├── POWER.md        → Main document defining tools & workflows
├── steering/       → 15 domain knowledge files
├── templates/      → Built-in templates (Presets, Scaffolds, Build Configs, etc.)
└── src/            → 40+ TypeScript tool modules

Which "Unity MCP"? — three different projects

Three unrelated projects are called some variant of "Unity MCP". This Power targets only the first one. Mixing them produces tool names and ports that match nothing in this documentation. All three rows retrieved 2026-10-21.

Project	Identity	How it connects	Status
(a) CoplayDev MCP for Unity — what this Power uses	UPM `com.coplaydev.unity-mcp`, repo CoplayDev/unity-mcp, Python server published on PyPI as `mcpforunityserver`, MIT-licensed	streamable HTTP (default) at `http://127.0.0.1:8080/mcp`, or stdio through `uvx`; the Unity-side bridge also listens on TCP `6400`	Active. Verified-current release v10.3.0 (2026-10-04); this Power documents v10.3.0 or newer, minimum v10.0.0. 49 tool entrypoints across 10 groups
(b) IvanMurzak/Unity-MCP — a different project, not used here	UPM `com.ivanmurzak.unity.mcp`, repo IvanMurzak/Unity-MCP	a separate server binary downloaded into `Library/mcp-server/`; its port is derived from a hash of the project path (range 20000–29999), so there is no port to configure	Active, latest 1.3.0 (~2026-10-20). Its tool names and port scheme do not match this Power
(c) Unity's own in-Editor MCP server	shipped inside `com.unity.ai.assistant`; UI at `Edit > Project Settings > AI > Unity MCP`	the MCP client connects straight to the in-Editor server	Deprecated — see below

On the deprecation of (c), and why it does not affect this Power. Unity's documentation states that the MCP server inside the in-Editor AI assistant package is deprecated and that the Unity CLI (unity mcp) takes its place, shipping its own MCP server that speaks the same protocol (Unity CLI as the replacement for the in-Editor MCP server, retrieved 2026-10-21; the same notice appears in the package docs, com.unity.ai.assistant — Get started with MCP server, retrieved 2026-10-21). The same Unity page states that third-party MCP packages installed from GitHub to give agents access to Unity are unaffected by that deprecation. Project (a) — the bridge this Power uses — is therefore explicitly outside the scope of the deprecation, and this Power is not obsolete because of it.

Prerequisites

Unity Editor installed with a project open (see Setup alternatives below if you have restricted installation access) — Unity 6.4 is the target, Unity 6.0 the minimum for this Power
Kiro IDE installed
MCP for Unity v10.3.0 or newer (minimum v10.0.0) — if the project has com.coplaydev.unity-mcp 9.6.8 or older installed, upgrade it; the 9.6.8 → 10.3.0 change is purely additive, so there is no migration cost
Python 3.10 or newer plus uv — the bridge's server is a Python package (mcpforunityserver on PyPI) launched through uv/uvx. The MCP for Unity setup wizard can install uv for you; on Windows, point "Choose UV Install Location" at the WinGet shim (%LOCALAPPDATA%\Microsoft\WinGet\Links\uv.exe) if several uv.exe copies are on PATH
Node.js 18+ (for development/typechecking only — not required for basic usage with the Power)

Setup alternatives: Choose the installation method that works for your environment:

Standard setup: Follow the steps below (requires unrestricted software installation access)

Restricted environment: See the Troubleshooting section for alternative configuration options (e.g., stdio transport mode — a method that runs the MCP server as a child process instead of using HTTP)

Enterprise/managed environment: If your organization manages software installations, consult your IT department about licensing and installation procedures

Unity Editor offers a free Personal license for individuals, students, hobbyists, and small teams.

Installation

Step 1 — Install this Power in your IDE

Open Kiro → Left panel click Powers icon → Click "+" button → Select "Add Custom Power" → Select this project's root directory

Note: The underlying Unity MCP tools (CoplayDev/unity-mcp) are open-source and can also be used independently with any MCP-compatible client.

Step 2 — Install unity-mcp and Start MCP Server in Unity

Open Unity Editor → Window → Package Manager
Click "+" → "Add package from git URL..." → Paste the following URL and click Add:
```
https://github.com/CoplayDev/unity-mcp.git?path=/MCPForUnity#main
```
Alternatives to the git URL, if you prefer not to track main:
- Pin a release: replace #main with a tag, e.g. #v10.3.0
- OpenUPM: openupm add com.coplaydev.unity-mcp
- Asset Store: the "MCP for Unity" listing, then Package Manager → My Assets
On first import the package opens a setup wizard. The persistent UI afterwards is Window → MCP for Unity, which starts/stops the server, switches transport, and reconfigures clients.

The screenshot above was taken on an older build whose menu item read "Toggle MCP Window". Current builds use Window → MCP for Unity.
Confirm the status panel reads Connected, and read the server endpoint/port it displays — you will need that port below. Restart Server is the recovery action.

Pick exactly one MCP registration path

Two different mechanisms can register the Unity MCP server with Kiro, and they write to the same config file under different names. Running both leaves two servers pointing at the same Unity Editor, which produces duplicate tool surfaces and ambiguous resource reads.

Path A — let this Power register the server. Install the Power and leave its mcp.json alone. A Legacy (POWER.md) power's MCP servers are registered into ~/.kiro/settings/mcp.json under the Powers section, with the server name namespaced by Kiro.
Path B — let Unity configure Kiro. In Unity, Window → MCP for Unity → Configure All Detected Clients (or select Kiro and Configure Selected). The package writes a server entry named unityMCP into the same file.

If Kiro's MCP panel shows two Unity MCP servers, disable one and restart Kiro. The three config locations that matter: this Power's own mcp.json, user-level ~/.kiro/settings/mcp.json, and workspace-level .kiro/settings/mcp.json.

MCP Connection Configuration

Automatic Configuration (Recommended)

In Unity, Window → MCP for Unity → confirm the transport is HTTP → Configure All Detected Clients (or select Kiro and Configure Selected). Kiro is a first-class supported client, so this writes a port-accurate entry into ~/.kiro/settings/mcp.json under the server key unityMCP.

Read the real port

Do not treat 8080 as a constant. The port is whatever the server was launched with (--http-url), it is user-editable, and 8080 collides with other services (upstream names Tailscale as an example and suggests moving to 8090). The MCP for Unity window shows the live endpoint — if it is not 8080, the URL is http://127.0.0.1:<that port>/mcp.

You can also read the port straight off disk: the running server writes a pidfile named after its port under the Unity project.

<UnityProject>\Library\MCPForUnity\RunState\mcp_http_<port>.pid

So mcp_http_8080.pid means the server is serving http://127.0.0.1:8080. On the install this Power was verified against, that is exactly what was there — the server's own command line was mcp-for-unity --transport http --http-url http://127.0.0.1:8080 --project-scoped-tools --pidfile ...mcp_http_8080.pid.

Manual Configuration (last resort)

Edit mcp.json only if the two steps above did not produce a working entry.

HTTP mode (default transport — local-only, communicates with the Unity Editor on your machine):

Security Note: HTTP is used intentionally here. The server binds loopback only (127.0.0.1 / ::1); binding a LAN address requires Advanced Settings → Allow LAN Bind (HTTP Local), and a remote endpoint must be https://. Traffic on the default setup never leaves your machine, so HTTPS is not required.

{
  "mcpServers": {
    "unity-mcp": {
      "url": "http://127.0.0.1:8080/mcp",
      "type": "http",
      "env": {},
      "disabled": false
    }
  }
}

Replace 8080 with the port shown in the Unity window. The mode key is type, not transport. 127.0.0.1 is deliberate: upstream docs print localhost, but the Unity side's own default is the literal 127.0.0.1, and on Windows localhost can resolve to ::1 first.

Connection methods: HTTP (simpler, recommended) and stdio (backup option). Choose HTTP unless you hit a port conflict or a firewall.

Stdio mode (fallback — runs the MCP server as a subprocess, a separate process managed by Kiro). The PyPI distribution is mcpforunityserver and the console entrypoint is mcp-for-unity; --transport stdio is required. There is no unity-mcp package on PyPI — earlier versions of this README documented uvx unity-mcp, which is why that fallback never launched.

Windows (use an absolute uvx.exe path — the WinGet shim is the recommended one):

{
  "mcpServers": {
    "unity-mcp": {
      "command": "C:/Users/<you>/AppData/Local/Microsoft/WinGet/Links/uvx.exe",
      "args": ["--from", "mcpforunityserver", "mcp-for-unity", "--transport", "stdio"],
      "type": "stdio",
      "env": {},
      "disabled": false
    }
  }
}

macOS/Linux (uvx on PATH is usually fine):

{
  "mcpServers": {
    "unity-mcp": {
      "command": "uvx",
      "args": ["--from", "mcpforunityserver", "mcp-for-unity", "--transport", "stdio"],
      "type": "stdio",
      "env": {},
      "disabled": false
    }
  }
}

Install Auto-Guidance Hook (Recommended)

This Power ships a UserPromptSubmit hook (Kiro 1.0 v1 schema) that reminds the AI to activate the Power and load the appropriate Steering File before processing each request.

mkdir -p .kiro/hooks
cp hooks/unity-power-auto-activate.json .kiro/hooks/unity-power-auto-activate.json

Verify Connection

Type any Unity-related command in the IDE (e.g., "List all objects in the current scene"). If the AI responds correctly, the connection is successful.

Usage

Tell the AI what you'd like to do in natural language. It will automatically select and execute the appropriate MCP tools.

Example Commands

"Set all models in the Characters folder to Humanoid rig"
"Create a 3D first-person scene"
"Build for Windows"
"Check the project's code architecture"
"Check Android platform compatibility"
"Analyze dependencies for hero.fbx"

Demo: Build an Interactive Scene and Run a Full Quality Check

The following demonstration uses an interactive 3D scene with collectible items as an example. We chose this scenario because it demonstrates multiple Unity systems (physics, rendering, UI, scripting) in a compact example. The same workflow steps (scene setup, code quality checks, performance analysis, platform compatibility) apply to any Unity project — whether building games, simulations, training applications, architectural visualizations, or other interactive experiences.

Non-game alternative: For an architectural visualization project, replace the 3D scene with a building walkthrough, replace collectible objects with interactive waypoints, replace scoring with progress tracking, and replace the HUD with an information panel. The workflow steps remain identical.

Phase 1: Create the Scene (Game Example)

Alternative for non-game projects: Replace collectible objects with interactive waypoints, scoring with progress tracking, and the HUD with an information panel. The workflow steps remain identical.

First, build a playable 3D scene:

Create a 3D scene with:
- Terrain (rolling grassland)
- Directional and ambient lighting
- Character controller (WASD movement + mouse look)
- Collectible objects (gems and coins scattered around)
- HUD Canvas with score and timer display
Name the scene Level01 and save it

Next, add interactive gameplay mechanics:

Add core interaction gameplay:
1. Collection system: walk near objects to collect, objects glow when in range
2. 5 collectible items (colored gems) placed around the terrain
3. Items disappear with particle effects when collected
4. Scoring system: top-left score display, +100 per item collected
5. Show "COMPLETE" when all items are collected

Now create a level configuration system:

Create a ScriptableObject called LevelConfig with: level name (string), difficulty (int, 1-10),
time limit (float), enemy wave list (nested: enemy type string + count int + spawn delay float),
and generate a custom Inspector

Why these checks matter: In production Unity projects, catching architecture violations and performance issues early prevents costly refactoring later. The checks below typically surface 80% of common issues in under a minute.

Phase 2: Quality Checks and Optimization

With the scene in place, run a code quality check:

Check all C# code against MVC architecture rules, scan naming conventions,
layer dependencies and circular references, list all violations with fix suggestions

Then scan for performance issues:

Scan all C# scripts for performance anti-patterns, analyze current scene Draw Calls
and memory usage, generate a complete performance report sorted by severity

Verify cross-platform compatibility:

Check all Shader platform compatibility for Android and iOS, verify memory budgets,
categorize issues as Error/Warning/Suggestion, provide alternatives for incompatible Shaders

Finally, build and check results:

Build the project with Android release configuration, parse build logs for errors,
list each error's type, file location, and fix suggestions

Development

The TypeScript modules in src/ are standalone — there is no bundler and no build step. The test suite and the TypeScript compiler config are developer-local (git-ignored), so a fresh clone has no test runner configured; typecheck with explicit compiler flags instead:

npm install   # devDependencies only — the Power itself has no runtime dependencies

# typecheck (bash)
npx tsc --noEmit --strict --target ES2022 --module ESNext --moduleResolution bundler --skipLibCheck src/*.ts

# typecheck (PowerShell)
npx tsc --noEmit --strict --target ES2022 --module ESNext --moduleResolution bundler --skipLibCheck (Get-ChildItem src -Filter *.ts | ForEach-Object FullName)

Project Structure

kiro-unity-accelerator/
├── POWER.md                    # Main document for the AI assistant
├── mcp.json                    # MCP Server connection config
├── steering/                   # Domain knowledge Steering Files (15)
├── templates/                  # Built-in templates
│   ├── presets/                # Asset Presets (5)
│   ├── scaffolds/              # Scene Scaffolds (5)
│   ├── build-configs/          # Build Configurations (4)
│   ├── platform-profiles/      # Platform Profiles (5, including XR/VR)
│   ├── architecture-rules/     # Architecture Rules (3)
│   └── workflows/              # Workflow Templates (3)
├── src/                        # TypeScript tool modules (40+)
├── hooks/                      # Hook template (copy into .kiro/hooks/)
├── workshop/                   # Step-by-step prompt tutorials
├── image/                      # Documentation images
└── package.json

Troubleshooting

Problem	Solution
Kiro cannot connect to Unity	Ensure Unity Editor is open with a project loaded → `Window → MCP for Unity` → confirm the status panel reads Connected (use `Restart Server` if not)
Port 8080 is occupied	Change the port in MCP for Unity settings (upstream suggests 8090), re-run Configure All Detected Clients, restart Kiro, and make the `url` in `mcp.json` match the port shown in the Unity window
A documented tool is reported as not existing	Possibly its tool group is inactive — the bridge's declared default is `core` only, though on the verified install every tool was callable with no activation. Run `manage_tools(action: "list_groups")`, then `manage_tools(action: "sync")`, then `manage_tools(action: "activate", group: "<name>")`, and refresh or reconnect the MCP server afterwards (Kiro may cache the tool list). `list_groups` can report `enabled: false` for a group whose tools work, so judge by whether the retry succeeds
`Tool call denied by user's permissions`	A Kiro permission rule blocked the call before Unity saw it — not a bridge fault. Kiro exposes this Power's server as `power-kiro-unity-accelerator-unity-mcp`; check `~/.kiro/settings/permissions.yaml` (and the workspace-level file) for `capability: mcp` entries with `effect: deny` matching `power-<powerName>-<serverName>/<tool>`, and relax the rule if you want that tool available. On the machine this Power was verified against, such a rule denied `manage_build` and made the whole build workflow unrunnable
`Unknown action` inside a `batch_execute`	`batch_execute` goes straight to Unity and bypasses the bridge's Python server layer, so a server-layer action fails there even though it works. Re-run that one call directly before concluding the action does not exist
Two Unity MCP servers registered	Open `~/.kiro/settings/mcp.json` and Kiro's MCP panel; if both the Power's entry and `unityMCP` are present, disable one and restart Kiro (see "Pick exactly one MCP registration path")
Unity 6.3+ with the Unity AI Assistant package installed	The AI Assistant bundles a newer `System.Collections.Immutable` than the Roslyn dependency used by `validate_script` / `execute_code` expects. Upstream's fix is to place `System.Collections.Immutable` v9.0.0 into `Assets/Plugins/`
Asset operations unresponsive	Unity may be compiling; wait for compilation to complete, or read the `mcpforunity://editor/state` resource
TypeScript type errors	Run the flag-based typecheck in the Development section above; ensure `npm install` has been run

Security

See CONTRIBUTING for more information.

License

This library is licensed under the MIT-0 License. See the LICENSE file.

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Kiro Unity Accelerator

Features

Architecture

Which "Unity MCP"? — three different projects

Prerequisites

Installation

Step 1 — Install this Power in your IDE

Step 2 — Install unity-mcp and Start MCP Server in Unity

Pick exactly one MCP registration path

MCP Connection Configuration

Automatic Configuration (Recommended)

Read the real port

Manual Configuration (last resort)

Install Auto-Guidance Hook (Recommended)

Verify Connection

Usage

Example Commands

Demo: Build an Interactive Scene and Run a Full Quality Check

Phase 1: Create the Scene (Game Example)

Phase 2: Quality Checks and Optimization

Development

Project Structure

Troubleshooting

Security

License

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Name		Name	Last commit message	Last commit date
.agents/tasks/unity-6.4-compat-update		.agents/tasks/unity-6.4-compat-update
hooks		hooks
image		image
src		src
steering		steering
templates		templates
workshop		workshop
.gitignore		.gitignore
CODE_OF_CONDUCT.md		CODE_OF_CONDUCT.md
CONTRIBUTING.md		CONTRIBUTING.md
LICENSE		LICENSE
POWER.md		POWER.md
README.md		README.md
README_CN.md		README_CN.md
README_JP.md		README_JP.md
README_KR.md		README_KR.md
README_ZH.md		README_ZH.md
mcp.json		mcp.json
package.json		package.json

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Kiro Unity Accelerator

Features

Architecture

Which "Unity MCP"? — three different projects

Prerequisites

Installation

Step 1 — Install this Power in your IDE

Step 2 — Install unity-mcp and Start MCP Server in Unity

Pick exactly one MCP registration path

MCP Connection Configuration

Automatic Configuration (Recommended)

Read the real port

Manual Configuration (last resort)

Install Auto-Guidance Hook (Recommended)

Verify Connection

Usage

Example Commands

Demo: Build an Interactive Scene and Run a Full Quality Check

Phase 1: Create the Scene (Game Example)

Phase 2: Quality Checks and Optimization

Development

Project Structure

Troubleshooting

Security

License

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