dcc-mcp-openusd 0.4.0

OpenUSD MCP server with daemon runtime — uvx-launchable, defaults to Pixar USD bindings

dcc-mcp-openusd

OpenUSD adapter and skills for the DCC Model Context Protocol ecosystem.

dcc-mcp-openusd runs a headless OpenUSD-oriented MCP server that can create portable USD project folders, author simple stages, add references, validate stages, and package USDZ-like archives. It is designed to plug into the dcc-mcp-core gateway and skills-first workflow.

Install

pip install dcc-mcp-openusd

This release train requires dcc-mcp-core>=0.18.7.

The base install operates in text-fallback mode: it reads and writes USDA text without requiring the Pixar USD runtime. This mode is suitable for lightweight agents, CI gates, and environments where native USD libraries are unavailable.

For full OpenUSD runtime behavior, install the optional Pixar USD bindings:

pip install "dcc-mcp-openusd[openusd]"

The [openusd] extra pulls in usd-core>=24.11 (the Pixar open-source USD Python bindings, importable as pxr). With pxr installed, all stage authoring, material binding, camera/light definition, time-sampled animation, and composition-arc operations go through the native USD runtime.

Runtime mode detection

from dcc_mcp_openusd.runtime import detect_runtime

runtime = detect_runtime()
print(runtime.has_pxr)   # True when pxr is installed
print(runtime.version)   # e.g. "24.11"

Every public function returns a "runtime" field in its result dict — "pxr" when the native runtime was used, "text-fallback" otherwise.

Feature boundary

Feature	Text-fallback	pxr runtime
create_stage, create_project	USDA text	Native Usd.Stage
list_stage, define_xform, define_prim	USDA parse + insert	Native API
add_reference, set_xform_ops	USDA text	Native API
validate_stage, snapshot_stage, package_usdz	USDA checks	Native validation
Material binding (UsdShade)	—	Requires pxr
Camera / Light (UsdGeomCamera, UsdLux)	—	Requires pxr
Time-sampled animation	—	Requires pxr
Sublayer / payload composition	—	Requires pxr

Advanced features that cannot be expressed through text-fallback raise OpenUsdError("... requires the Pixar USD (pxr) package. Install it with: pip install usd-core") when pxr is absent.

Run

dcc-mcp-openusd --port 8765

Then connect an MCP client to:

http://127.0.0.1:8765/mcp

Bundled Skills

The first version ships three bundled skills:

Skill	Purpose
openusd-project	Create self-contained project folders and snapshots.
openusd-stage	Create stages, list prims, define xforms, and add references.
openusd-validate	Validate stage invariants and package a USDZ-style archive.

Agents should follow the normal DCC-MCP flow:

1. search_skills(query="openusd stage")
2. load_skill("openusd-stage")
3. Call a typed tool such as openusd_stage__create_stage
4. Validate with openusd_validate__validate_stage

Scope

This repository is intentionally an adapter/domain-skill package, not a new core USD engine. dcc-mcp-core remains the shared transport, gateway, validation, telemetry, and skill-loading foundation. This package owns OpenUSD-specific project semantics, stage authoring tools, validation policy, and packaging workflows.

Development

# Minimal setup (text-fallback, fast CI gate)
pip install -e ".[dev]"
pytest tests/ --ignore=tests/e2e

# Full setup (pxr runtime, material/light/animation/composition tests)
pip install -e ".[dev,openusd]"
pytest tests/e2e/ -v
ruff check src tests tools
python -m build

The CI matrix enforces both modes:

• test-minimal — no pxr, runs unit tests + contract test (text-fallback baseline)
• test-openusd — with pxr, runs the e2e golden-path suite

Release

The repository uses release-please. The baseline version is 0.0.0 so the first release PR will cut v0.1.0. PyPI publishing is wired through the pypi GitHub environment.