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# HoudiniMCP – Connect Houdini to Claude via Model Context Protocol
**HoudiniMCP** allows you to control **SideFX Houdini** from **Claude** using the **Model Context Protocol (MCP)**. It consists of:
1. A **Houdini plugin** (Python package) that listens on a local port (default `localhost:9876`) and handles commands (creating and modifying nodes, executing code, etc.).
2. An **MCP bridge script** you run via **uv** (or system Python) that communicates via **std**in/**std**out with Claude and **TCP** with Houdini.
Below are the complete instructions for setting up Houdini, uv, and Claude Desktop.
---
## Table of Contents
1. [Requirements](#requirements)
2. [Houdini MCP Plugin Installation](#houdini-mcp-plugin-installation)
1. [Folder Layout](#folder-layout)
2. [Shelf Tool (Optional)](#shelf-tool-optional)
3. [Packages Integration (Optional)](#packages-integration-optional)
3. [Installing the `mcp` Python Package](#installing-the-mcp-python-package)
1. [Using uv on Windows](#using-uv-on-windows)
2. [Using pip Directly](#using-pip-directly)
4. [Bridging Script and Claude for Desktop](#bridging-script-and-claude-for-desktop)
1. [The Bridging Script](#the-bridging-script)
2. [Telling Claude Desktop to Use Your Script](#telling-claude-desktop-to-use-your-script)
5. [Testing & Usage](#testing--usage)
6. [Troubleshooting](#troubleshooting)
---
## Requirements
- **SideFX Houdini**
- **uv**
- **Claude Desktop** (latest version)
---
## 1. Houdini MCP Plugin Installation
### 1.1 Folder Layout
Create a folder in your Houdini scripts directory:
C:/Users/YourUserName/Documents/houdini19.5/scripts/python/houdinimcp/
Inside **`houdinimcp/`**, place:
- **`__init__.py`** – handles plugin initialization (start/stop server)
- **`server.py`** – defines the `HoudiniMCPServer` (listening on port `9876`)
- **`houdini_mcp_server.py`** – optional bridging script (some prefer a separate location)
- **`pyproject.toml`**
*(If you prefer, `houdini_mcp_server.py` can live elsewhere. As long as you know its path for running with `uv`.)*
### 1.2 Shelf Tool
create a **Shelf Tool** to toggle the server in Houdini:
1. **Right-click** a shelf → **"New Shelf..."**
Name it "MCP" or something similar
2. **Right-click** again → **"New Tool..."**
Name: "Toggle MCP Server"
Label: "MCP"
3. Under **Script**, insert something like:
```python
import hou
import houdinimcp
if hasattr(hou.session, "houdinimcp_server") and hou.session.houdinimcp_server:
houdinimcp.stop_server()
hou.ui.displayMessage("Houdini MCP Server stopped")
else:
houdinimcp.start_server()
hou.ui.displayMessage("Houdini MCP Server started on localhost:9876")
```
### 1.3 Packages Integration
If you want Houdini to auto-load your plugin at startup, create a package file named houdinimcp.json in the Houdini packages folder (e.g. C:/Users/YourUserName/Documents/houdini19.5/packages/):
```json
{
"path": "$HOME/houdini19.5/scripts/python/houdinimcp",
"load_package_once": true,
"version": "0.1",
"env": [
{
"PYTHONPATH": "$PYTHONPATH;$HOME/houdini19.5/scripts/python"
}
]
}
```
### 2 Using uv on Windows
```powershell
# 1) Install uv
powershell -c "irm https://astral.sh/uv/install.ps1 | iex"
# 2) add uv to your PATH (depends on the user instructions) from cmd
set Path=C:\Users\<YourUserName>\.local\bin;%Path%
# 3) In a uv project or the plugin directory
cd C:/Users/<YourUserName>/Documents/houdini19.5/scripts/python/houdinimcp/
uv add "mcp[cli]"
# 4) Verify
uv run python -c "import mcp.server.fastmcp; print('MCP is installed!')"
```
### 3 Telling Claude for Desktop to Use Your Script
Go to File > Settings > Developer > Edit Config >
Open or create:
claude_desktop_config.json
Add an entry:
```json
{
"mcpServers": {
"houdini": {
"command": "uv",
"args": [
"run",
"python",
"C:/Users/<YourUserName>/Documents/houdini19.5/scripts/python/houdinimcp/houdini_mcp_server.py"
]
}
}
}
```
if uv run was successful and claude failed to load mcp, make sure claude is using the same python version, use:
```cmd
python -c "import sys; print(sys.executable)"
```
to find python, and replace "python" with the path you got.
### 4 Use Cursor
Go to Settings > MCP > add new MCP server
add the same entry in claude_desktop_config.json
you might need to stop claude and restart houdini and the server
### 5 OPUS integration
OPUS provide a large set of furniture and environmental procedural assets.
you will need a Rapid API key to log in. Create an account at: [RapidAPI](https://rapidapi.com/)
Subscribe to OPUS API at: [OPUS API Subscribe](https://rapidapi.com/genel-gi78OM1rB/api/opus5/pricing)
Get your Rapid API key at [OPUS API](https://rapidapi.com/genel-gi78OM1rB/api/opus5)
add the key to urls.env
### 4 Acknowledgement
Houdini-MCP was built following [blender-mcp](https://github.com/ahujasid/blender-mcp). We thank them for the contribution.
