Unity Asset Store MCP

MCP server for browsing, downloading, extracting, and converting Unity Asset Store packages. Works with Claude Code and other MCP-compatible AI agents.

Install

# Clone and install dependencies
git clone <repo-url> && cd UnityStoreMCP
bun install

Optional: conversion dependencies

• FBX to glTF: brew install fbx2gltf (macOS) or install FBX2glTF
• TGA/PSD to PNG: uses macOS sips by default, or ffmpeg as fallback

Setup

Add to your MCP client config (e.g. ~/.claude/settings.json):

{
  "mcpServers": {
    "unity-store": {
      "command": "bun",
      "args": ["run", "/path/to/UnityStoreMCP/src/index.ts"]
    }
  }
}

Authentication

The server authenticates using cookies from assetstore.unity.com:

1. Log into https://assetstore.unity.com in your browser
2. Open DevTools (F12) → Network tab
3. Copy the full Cookie header value from any request
4. Use configure-auth with method: "session_token" and paste the cookie string

The server exchanges these cookies for the internal tokens needed for downloads.

Tools

| Tool | Description | |------|-------------| | configure-auth | Authenticate with Unity Asset Store | | search-assets | Search the store by query | | get-asset-details | Get details for specific asset IDs | | list-my-assets | List your purchased/owned assets | | download-asset | Download a .unitypackage by ID | | list-local-packages | List Unity Editor cached packages | | inspect-package | Preview package contents without extracting | | extract-package | Extract .unitypackage to disk | | convert-assets | Convert Unity assets to Three.js formats (FBX→glTF, materials, textures) | | list-extracted | List extracted/converted directories | | browse-files | Browse files in asset directories |

Data Directory

Downloaded, extracted, and converted assets are stored in ~/.unity-mcp/. Override with UNITY_MCP_DATA_DIR environment variable.

Package Decryption

Unity Asset Store packages are served as AES-256-CBC encrypted blobs. The download-asset tool handles this automatically:

1. Fetches the download URL and a 96-character hex decryption key from Unity's Kharma API
2. Downloads the encrypted file via streaming (supports files >2GB)
3. Splits the key: first 32 bytes → AES key, last 16 bytes → IV
4. Decrypts with openssl and outputs a standard .unitypackage (gzip tar)