get_stateLABSCO SUMMARY
The assistant drives the Sweet Home 3D window you already have open, right through to the ray-traced render.
Because the server lives inside the application, every command lands in the live document: an agent can raise walls, drop catalog furniture into them, set a camera and ask for a Sunflow render or an OBJ export without a file changing hands. Object IDs are stable UUIDs across calls, coordinates are in centimetres, and checkpoints let you snapshot the scene before letting it attempt something larger.
What it is
A Sweet Home 3D plugin that runs the MCP server inside the application itself, over HTTP on port 9877 at http://127.0.0.1:9877/mcp. There is no proxy and no second process: the assistant edits the document you are looking at, across 42 commands in 12 categories.
What you get
- Walls and rooms: create_wall between two points, create_walls for a rectangular room, modify_wall for height, thickness, colour, arc and coordinates, connect_walls so corners render correctly, create_room_polygon from a list of points
- Furniture from the built-in catalog — list_categories and list_furniture_catalog to browse, place_furniture to place, modify_furniture to move, rotate, resize or recolour, plus group_furniture, ungroup_furniture and duplicate_objects
- place_door_or_window works out the position and angle inside the wall for you
- Textures and appearance: list_textures_catalog, apply_texture onto a wall side or a room surface, set_environment for ground and sky colour, lighting, wall transparency and drawing mode
- generate_shape builds custom geometry — box, sphere, cylinder, cone, wedge, arch, stairs, torus, hemisphere and pipe, plus extrude, mesh and boolean union, subtract and intersect
- Output in four forms: render_photo for a ray-traced Sunflow image, export_plan_image for a PNG plan, export_svg, and export_to_obj for the 3D scene with materials and textures
- Multi-storey plans through add_level, list_levels, set_selected_level and delete_level, and add_label and add_dimension_line for annotation
- checkpoint, restore_checkpoint and list_checkpoints give an in-memory undo timeline, and batch_commands sends several commands in one request
Requirements
Sweet Home 3D 6.0 or newer on Java 11 or newer. Download the .sh3p plugin from the repository's releases, drop it into the Sweet Home 3D plugins folder and restart — the server then starts on port 9877 by itself, and Tools → MCP Server… shows its status and can write the Claude Desktop config for you. Point the client at http://localhost:9877/mcp as an HTTP server. The Mac App Store build is sandboxed and cannot open a listening socket, so use the standalone build from sweethome3d.com instead.
Setup effort
Follow the published steps
USE CASES
01
Laying out a room from a description
create_walls raises the four walls of a rectangular room, connect_walls squares up the corners, and create_room_polygon handles anything that is not a rectangle.
02
Furnishing a plan from the built-in catalog
Browse the catalog by name or category, place what you want, and let place_door_or_window compute where a door sits in the wall.
03
Producing an image to show someone
Set the camera to a viewpoint or a target object, then render a ray-traced photo or export the 2D plan as PNG or SVG.
04
Trying a bigger change you may want to walk back
Take a checkpoint before the change, list the snapshots afterwards, and restore the one you want.
05
Handing the model to another tool
export_to_obj packages the 3D scene with its materials and textures, export_svg gives the plan as vectors, and save_home writes a normal .sh3d file.
42 tools
Listed in project docs. Your client may show a different list.
clear_scenecreate_wallcreate_wallsmodify_walldelete_wallconnect_wallscreate_room_polygonmodify_roomdelete_roomlist_categorieslist_furniture_catalogplace_furnituremodify_furnituredelete_furnitureduplicate_objectsgroup_furnitureungroup_furnitureplace_door_or_windowlist_textures_catalogapply_textureset_environmentgenerate_shapeadd_labeladd_dimension_lineset_camerastore_cameraget_camerasadd_levellist_levelsset_selected_leveldelete_levelrender_photoexport_plan_imageexport_svgexport_to_objsave_homeload_homecheckpointrestore_checkpointlist_checkpointsbatch_commandsBEFORE YOU INSTALL
What to know first
Tools you get
42 tools named in the project's documentation. The project calls these commands; batch_commands runs multiple commands in one request and adds no capability of its own.
Where it runs
The documented client runs the server on your machine.
INSTALLATION
Connect your client
Server setup
Download the latest .sh3p file from the project's releases:
URL
https://github.com/grimashevich/sweethome3d-mcp-server/releasesCopy it to your Sweet Home 3D plugins folder (Windows: %APPDATA%\eTeks\Sweet Home 3D\plugins\; macOS: ~/Library/Application Support/eTeks/Sweet Home 3D/plugins/; Linux: ~/.sweethome3d/plugins/).
(Re)start Sweet Home 3D. The MCP server starts automatically on port 9877; Tools → MCP Server... shows its status.
MCP Clients
Claude Code
CLAUDE CODE · JSON
{
"mcpServers": {
"sweethome3d": {
"type": "http",
"url": "http://localhost:9877/mcp"
}
}
}
