dcc-mcp-houdini 0.24.0

SideFX Houdini adapter for the DCC Model Context Protocol (MCP) ecosystem — exposes Houdini tools via MCP

dcc-mcp-houdini

SideFX Houdini adapter for the DCC Model Context Protocol (MCP) ecosystem. It embeds a Streamable HTTP MCP server inside Houdini/hython and exposes skills-first Houdini automation tools to agents.

Six-DCC production showcase

This image is a real Blender render of a Houdini-authored animated effect. In the tested six-instance workflow, Maya supplied the animated IK/FK rig, 3ds Max baked and re-exported the character, Houdini 21 generated 420 procedural particle instances and a 48-frame Alembic cache, and a second Houdini GUI instance re-imported that cache before Blender assembled the final shot. The rock asset came from the no-token dcc-asset-polyhaven marketplace skill and is CC0-1.0.

Features

• Embedded MCP Streamable HTTP server inside Houdini (OS-assigned instance port)
• Auto-gateway with first-wins election (gateway port 9765)
• Progressive skill loading (discover → load → unload)
• Houdini Python (hython) and interactive UI-thread dispatch
• Python 3.7+ package metadata for older Houdini runtimes
• Bundled skills for scripting, scene inspection, node authoring, HDA execution, and automation
• Wheel, sdist, and Houdini quickinstall ZIP release assets
• Prometheus metrics endpoint (/metrics), job persistence, and workflow engine support
• Optional licensed Houdini Docker E2E workflow

Agent install (recommended)

Let your AI agent do the setup. In an MCP-capable agent (Cursor, Claude, etc.), just say:

帮我参考 loonghao/dcc-mcp-houdini/install.md 去安装

The agent reads install.md, runs the dcc-mcp-houdini-setup skill to install dependencies into Houdini's hython, generates an MCP host config, guides the Houdini package startup hooks step, and runs a smoke prompt to confirm the connection.

Installation

Release Wheel

pip install dcc-mcp-houdini

For an unreleased GitHub asset, install a release wheel directly:

pip install https://github.com/loonghao/dcc-mcp-houdini/releases/download/v0.9.1/dcc_mcp_houdini-0.9.1-py3-none-any.whl

Houdini Quickinstall ZIP

Download dcc_mcp_houdini_quickinstall_<platform>_v<version>.zip from GitHub Releases, extract it to a stable folder, then run:

powershell -ExecutionPolicy Bypass -File install.ps1 -HoudiniVersion 20.5

For an isolated or custom package location, pass -PackagesDir explicitly:

powershell -ExecutionPolicy Bypass -File install.ps1 -HoudiniVersion 20.5 -PackagesDir C:\temp\houdini-packages

DCC_MCP_HOUDINI_PACKAGES_DIR provides the same override on every platform; on Windows, the explicit -PackagesDir argument takes precedence. Changing the HOME environment variable inside PowerShell does not redirect its automatic $HOME variable, so use this override for deterministic isolated installs.

On Linux/macOS:

chmod +x install.sh
./install.sh 20.5

The package writes a Houdini package JSON into the user preferences folder. scripts/123.py handles an empty startup and scripts/456.py handles a loaded scene; both reuse one bootstrap that extracts bundled wheels into vendor/ and starts the MCP server unless DCC_MCP_HOUDINI_AUTOSTART=0.

Isolated background ROP workers receive DCC_MCP_BACKGROUND_RENDER=1 in their child environment. Package and custom 123.py/456.py startup hooks must skip MCP adapter autostart when that marker is present; the parent Houdini environment is not modified. Background render cancellation uses only live child-process handles owned by the current adapter process; status-file PIDs are never used as process ownership evidence.

Usage

import dcc_mcp_houdini

server = dcc_mcp_houdini.start_server()
print(server.mcp_url)  # Exact direct endpoint selected by the OS

start_server() is the interactive Houdini API and uses Houdini's budgeted event-loop pump. Headless Hython must keep its owning thread available for HOM work; launch the foreground pump instead:

hython -m dcc_mcp_houdini

or call dcc_mcp_houdini.serve_headless(...) from a dedicated Hython entrypoint. A plain headless start_server() fails before tools are registered instead of silently executing HOM on an HTTP worker.

Default minimal mode (DCC_MCP_MINIMAL=1) loads only:

• houdini-scripting
• houdini-scene

Use progressive discovery for heavier tools:

search_skills(query="hda")
load_skill("houdini-hda")
call houdini_hda__execute_hda

Local MCP debug (Cursor / Claude)

See docs/guide/local-mcp-debug.md and copy examples/mcp/cursor-houdini-streamable-http.json into your MCP host config.

Development

# Install dependencies
just dev

# Run tests
just test

# Lint
just lint-all

# Windows: build dcc-mcp-core with Houdini's Python and symlink
just houdini-version=20.5 houdini-dev-build-link-core-win

# Windows: start Houdini with debugpy
just houdini-version=20.5 houdini-dev-debug-win

# Build wheel + platform quickinstall package
just build-houdini-package platform=win64

Release Publishing

The Release workflow publishes to PyPI when release-please creates a new release. To backfill an existing GitHub release tag, run the Release workflow manually with tag_name=vX.Y.Z and publish_to_pypi=true. Publishing uses PyPI trusted publishing when configured, or PYPI_API_TOKEN when that secret is available.

Bundled Skills (30 packages, 185 tools)

Full authoritative index with ready-made task chains: src/dcc_mcp_houdini/skills/SKILLS_INDEX.md

bootstrap (default loaded)

Skill	Tools
houdini-scripting	execute_python, get_session_info

scene (partial default — houdini-scene only)

Skill	Tools	Load
houdini-scene	get_scene_info, list_obj_nodes, list_child_nodes, get_node_info	default
houdini-scene-edit	new_scene, open_scene, save_scene, get_selection, set_selection, find_nodes, list_cameras, get_bounding_box	on demand

authoring (load on demand)

Skill	Tools
houdini-nodes	create_node, set_node_parms, connect_nodes, cook_node, layout_children, delete_node
houdini-object-ops	rename_node, duplicate_node, parent_node, set_node_flags, set_node_lock, get_transform, set_transform
houdini-parameters	list_parms, get_parms, get_parm_templates, get_expression, set_parms, add_spare_parm, remove_spare_parm, set_expression, clear_expression
houdini-node-graph	get_connections, connect_input, disconnect_input
houdini-geometry	create_primitive, get_geometry_info, list_attributes, list_groups, get_cook_status
houdini-mesh-ops	transform_geometry, merge_geometry, blast_geometry, group_geometry, add_normals, triangulate_geometry, convert_geometry
houdini-camera-light	list_cameras, create_camera, update_camera, frame_view, get_view_state, create_light, update_light
houdini-materials	create_material, assign_material, build_materialx_pbr, validate_materialx_pbr
houdini-lookdev	list_materials, list_assignments, get_material_parms, set_material_parms, get_shader_connections, connect_shader, disconnect_shader, reset_material, save_preset, list_presets, load_preset, delete_preset
houdini-hda	install_hda_file, list_hda_definitions, execute_hda, save_node_as_hda, promote_hda_parameters, author_hda_interface, publish_hda_library, validate_hda_contract, update_hda_definition, sync_hda_instance
houdini-chops	create_chop_network, create_motionclip, create_audio_driven, apply_filter, export_to_keyframes, get_channel_info
houdini-constraints	create_parent_constraint, create_blend_constraint, create_position_constraint, create_orient_constraint, list_constraints, delete_constraint
houdini-export-preset	list_export_presets, save_export_preset, load_export_preset, delete_export_preset
houdini-kinefx	create_rig, set_rig_pose, capture_joints, apply_mocap
houdini-light-rig	create_three_point_light_rig, create_area_softbox, create_hdri_world, list_light_rigs, set_light_rig_intensity, aim_light_at_object, group_lights, set_render_view_transform, get_lighting_summary
houdini-material-library	save_material_preset, list_material_presets, load_material_preset, delete_material_preset, get_shader_assignment, get_material_connections, set_material_attribute, assign_texture, list_images, reload_image, list_color_spaces, set_color_management
houdini-texture-bake	list_bake_targets, bake_textures, bake_ambient_occlusion, bake_lighting, transfer_maps

interchange (load on demand)

Skill	Tools
houdini-interchange	probe_file, import_geometry, export_geometry, export_alembic, export_fbx, export_usd
houdini-import-to-scene	import_to_scene

pipeline (load on demand)

Skill	Tools
houdini-render	capture_viewport, flipbook, get_render_settings, set_render_settings, validate_karma_stage, render_rop, get_render_job, cancel_render_job, create_render_layer, configure_aovs, manage_takes, get_render_stats
houdini-karma	configure_karma, set_material_override, configure_light_mixer, set_image_output
houdini-husk	render_with_husk, create_checkpoint, create_snapshot, set_husk_options
houdini-animation	get_timeline, set_timeline, set_keyframe, get_keyframes, delete_keyframes, list_animated_parms, validate_loop_contract, get_channel_info, export_channels, import_channels, bake_channels, cache_simulation
houdini-hda-automation	scan_hda_libraries, inspect_hda_definition, instantiate_hda, validate_hda, cook_top_network, execute_rop_chain
houdini-pipeline	set_project, get_project, tag_asset_metadata, get_asset_metadata, validate_scene, collect_dependencies, export_shot_package
houdini-dev	attach_project, reload_modules, run_entrypoint, run_script, start_debugpy, introspect_hom, ui_snapshot, ui_action
houdini-automation	run_python_file, set_frame_range, save_hip_file, load_hip_file, build_node_chain

CI and Houdini Docker

Normal CI runs without Houdini installed: unit tests, skill validation, Python 3.7 syntax checks, wheel/sdist build, and quickinstall ZIP assembly.

Live Houdini E2E is in .github/workflows/e2e.yml. It defaults to sabjorn/hbuild-worker:21.0.559-base and runs only when SideFX licensing secrets are configured. See docs/ci/houdini-docker.md.

Project Structure

dcc-mcp-houdini/
├── src/dcc_mcp_houdini/        # Python package and bundled skills
├── packaging/                  # Quickinstall ZIP assembly
├── tests/                      # Unit and packaging tests
├── tools/                      # Dev, lint, and syntax scripts
├── examples/                   # Usage examples
├── docs/                       # Guides and CI notes
├── justfile                    # Task runner
└── pyproject.toml              # Build config

Requirements

• Houdini with Python 3.7+ (hython or interactive Houdini)
• dcc-mcp-core >= 0.19.45
• Quickinstall bundles the latest non-prerelease dcc-mcp-core >= 0.19.45,<1.0.0 by default, or the validated core_version passed to a release backfill; no old-core pin is active.
• See pyproject.toml for full dependencies

License

MIT