Sweet Home 3D MCP Plugin

A plugin for Sweet Home 3D that embeds an MCP (Model Context Protocol) server directly inside the application. Lets Claude and other AI assistants control Sweet Home 3D over HTTP — create walls, place furniture, render photos, and more — without any external proxy or separate server process.

Claude Desktop / Claude Code
         │  HTTP (JSON-RPC 2.0)
         ▼
┌─────────────────────────────────────┐
│  Sweet Home 3D  +  MCP Plugin       │
│  Built-in HTTP server on port 9877  │
│  http://127.0.0.1:9877/mcp         │
└─────────────────────────────────────┘

Screenshots

Requirements

| Requirement | Version | |-------------|---------| | Sweet Home 3D | 6.0 or newer | | Java (bundled with SH3D or system) | 11 or newer |

Note: Sweet Home 3D ships with a bundled JRE. Make sure it is Java 11+. Very old SH3D builds (32-bit Windows installer with JRE 1.8) will silently fail to load the plugin due to UnsupportedClassVersionError.

Installation

Step 1. Download the latest .sh3p file from Releases.

Step 2. Copy it to your Sweet Home 3D plugins folder:

| OS | Plugins folder | |----|----------------| | Windows | %APPDATA%\eTeks\Sweet Home 3D\plugins\ | | macOS | ~/Library/Application Support/eTeks/Sweet Home 3D/plugins/ | | Linux | ~/.sweethome3d/plugins/ |

Step 3. (Re)start Sweet Home 3D. The MCP server starts automatically on port 9877.

You can verify it is running: Tools → MCP Server... shows the server status.

Claude Configuration

Add to your Claude Desktop claude_desktop_config.json:

{
  "mcpServers": {
    "sweethome3d": {
      "type": "http",
      "url": "http://localhost:9877/mcp"
    }
  }
}

For Claude Code, create .mcp.json in your project directory:

{
  "mcpServers": {
    "sweethome3d": {
      "type": "http",
      "url": "http://localhost:9877/mcp"
    }
  }
}

The plugin also has a built-in "Auto-configure Claude Desktop" button in Tools → MCP Server... that writes this config automatically.

Available Commands

42 commands across 12 categories.

Scene

| Command | Description | |---------|-------------| | get_state | Full scene state: walls, furniture, rooms, camera, labels, levels | | clear_scene | Remove all objects from the scene |

Walls

| Command | Description | |---------|-------------| | create_wall | Single wall between two points | | create_walls | Rectangular room (4 connected walls) | | modify_wall | Change height, thickness, color, arc, coordinates | | delete_wall | Delete wall by ID | | connect_walls | Connect two walls for correct corner rendering |

Rooms

| Command | Description | |---------|-------------| | create_room_polygon | Room from an array of polygon points | | modify_room | Change name, floor/ceiling color, visibility | | delete_room | Delete room by ID |

Furniture

| Command | Description | |---------|-------------| | list_categories | All furniture catalog categories with item counts | | list_furniture_catalog | Browse catalog; filter by name, category, or type | | place_furniture | Place a catalog item in the scene | | modify_furniture | Move, rotate, resize, recolor furniture by ID | | delete_furniture | Delete furniture by ID | | duplicate_objects | Duplicate one or more objects by ID | | group_furniture | Group multiple pieces into one object | | ungroup_furniture | Split a group back into individual pieces |

Doors & Windows

... View full README on GitHub