Houdini CLI

Control a running Houdini instance from the terminal. No MCP, no Python venv, no JSON parsing. Just curl. Feed SKILL.md to your agent or mess with active Houdini session yourself from command line.

How It Works

hctl.sh ←→ HTTP ←→ RPC Service ←→ Houdini
 (curl)   :9876   (inside Houdini)

Related MCP server: Maya MCP

Install

1. Copy shelf tool to Houdini

cp houdini_rpc.shelf ~/Library/Preferences/houdini/21.0/toolbar/

2. Add hctl.sh to your PATH

ln -s /path/to/houdini-mcp-server/hctl.sh ~/.local/bin/hctl

Usage

Start Houdini and click the Start RPC shelf button.

# Execute Python in Houdini
hctl exec "hou.hipFile.path()"
hctl exec "hou.node('/obj').createNode('box')"
hctl exec "[n.path() for n in hou.selectedNodes()]"

# Scene info
hctl scene

# Network as Graphviz DOT graph
hctl dot /obj/geo1
hctl dot /obj/geo1 | dot -Tpng -o graph.png

# Node errors
hctl errors /obj

Raw curl

curl http://localhost:9876/scene
curl -X POST http://localhost:9876/exec -d "hou.hipFile.path()"
curl http://localhost:9876/dot?path=/obj/geo1
curl http://localhost:9876/errors?path=/obj

Environment

• HOUDINI_URL — RPC endpoint (default: http://localhost:9876)

Requirements

• Houdini 20.5+

• curl

Files

• hctl.sh — CLI wrapper, plain curl

• houdini_rpc_service.py — runs inside Houdini, executes code with hou module access

• houdini_rpc.shelf — shelf tool, copy to ~/Library/Preferences/houdini/<version>/toolbar/

Resources

Inspired by https://github.com/OleksandrChekhovskyi/hax/blob/master/docs/philosophy.md

License

MIT