unity-mcp/MCPForUnity
dsarno 62c015d873
Add create_child parameter to manage_prefabs modify_contents (#646)
* Add create_child parameter to manage_prefabs modify_contents

Enables adding child GameObjects to existing prefabs via headless editing.
Supports single object or array for batch creation in one save operation.

Features:
- Create children with primitive types (Cube, Sphere, etc.)
- Set position, rotation, scale on new children
- Add components to children
- Specify parent within prefab hierarchy for nested children
- Set tag, layer, and active state

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Address code review feedback for create_child validation

- Fix type hint to `tuple[dict | None, str | None]` to match actual returns
- Add explicit dict validation with clear error message including actual type
- Error on invalid component entries instead of silently ignoring them
- Return ErrorResponse for invalid tag/layer instead of just logging warnings

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Add unit tests for create_child prefab functionality

Tests cover:
- Single child with primitive type
- Empty GameObject (no primitive_type)
- Multiple children from array (batch creation)
- Nested parenting within prefab
- Error handling for invalid inputs

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-29 04:14:52 -08:00
..
Editor Add create_child parameter to manage_prefabs modify_contents (#646) 2026-01-29 04:14:52 -08:00
Runtime fix: improve manage_scene screenshot capture (#600) 2026-01-24 17:07:08 -05:00
Editor.meta Rename plugin folder to MCPForUnity (#303) 2025-10-03 20:23:28 -04:00
README.md Update the manual commands (#638) 2026-01-26 23:32:20 -05:00
README.md.meta Rename plugin folder to MCPForUnity (#303) 2025-10-03 20:23:28 -04:00
Runtime.meta Rename plugin folder to MCPForUnity (#303) 2025-10-03 20:23:28 -04:00
package.json chore: bump version to 9.2.0 2026-01-23 05:34:19 +00:00
package.json.meta Add .meta files (#472) 2025-12-19 18:59:19 -04:00

README.md

MCP for Unity — Editor Plugin Guide

Use this guide to configure and run MCP for Unity inside the Unity Editor. Installation is covered elsewhere; this document focuses on the Editor window, client configuration, and troubleshooting.

Open the window

  • Unity menu: Window > MCP for Unity

The window has four areas: Server Status, Unity Bridge, MCP Client Configuration, and Script Validation.


Quick start

  1. Open Window > MCP for Unity.
  2. Click “Auto-Setup”.
  3. If prompted:
    • Select the packaged server folder (Server) if you want to run the bundled implementation.
    • Install Python and/or uv/uvx if missing so the server can be managed locally.
    • For Claude Code, ensure the claude CLI is installed.
  4. Click “Start Bridge” if the Unity Bridge shows “Stopped”.
  5. Use your MCP client (Cursor, VS Code, Windsurf, Claude Code) to connect.

Server Status

  • Status dot and label:
    • Installed / Installed (Embedded) / Not Installed.
  • Mode and ports:
    • Mode: Auto or Standard.
    • Ports: Unity (varies; shown in UI), MCP 6500.
  • Actions:
    • Auto-Setup: Registers/updates your selected MCP client(s), ensures bridge connectivity. Shows “Connected ✓” after success.
    • Rebuild MCP Server: Rebuilds the Python based MCP server
    • Select server folder…: Choose the local Server folder (dev only; usually not needed when using uvx).
    • Verify again: Re-checks server presence.
    • If Python isnt detected, use “Open Install Instructions”.
  • HTTP Server Command foldout:
    • Expands to display the exact uvx command Unity will run.
    • Includes a copy button and the “Start Local HTTP Server” action so you can launch or reuse the command elsewhere.

Unity Bridge

  • Shows Running or Stopped with a status dot.
  • Start/Stop Bridge button toggles the Unity bridge process used by MCP clients to talk to Unity.
  • Tip: After Auto-Setup, the bridge may auto-start in Auto mode.

MCP Client Configuration

  • Select Client: Choose your target MCP client (e.g., Cursor, VS Code, Windsurf, Claude Code).
  • Per-client actions:
    • Cursor / VS Code / Windsurf:
      • Auto Configure: Writes/updates your config to launch the server via uvx with the current package version:
        • Command: uvx (or your overridden path)
        • Args: --from mcp-for-unity
      • Manual Setup: Opens a window with a pre-filled JSON snippet to copy/paste into your client config.
      • Choose UV Install Location: If uv/uvx isnt on PATH, select the executable.
      • A compact “Config:” line shows the resolved config file name once uv/server are detected.
    • Claude Code:
      • Register with Claude Code / Unregister MCP for Unity with Claude Code.
      • If the CLI isnt found, click “Choose Claude Install Location”.
      • The window displays the resolved Claude CLI path when detected.

Notes:

  • The UI shows a status dot and a short status text (e.g., “Configured”, “uv Not Found”, “Claude Not Found”).
  • Use “Auto Configure” for one-click setup; use “Manual Setup” when you prefer to review/copy config.

Script Validation

  • Validation Level options:
    • Basic — Only syntax checks
    • Standard — Syntax + Unity practices
    • Comprehensive — All checks + semantic analysis
    • Strict — Full semantic validation (requires Roslyn)
  • Pick a level based on your projects needs. A description is shown under the dropdown.

Troubleshooting


Tips

  • Use Cmd+Shift+M (macOS) / Ctrl+Shift+M (Windows, Linux) to toggle the MCP for Unity window.
  • Enable “Show Debug Logs” in the header for more details in the Console when diagnosing issues.