inventor-kit

IDW saved 2D display opens in the Viewer by default (partial support): Python API and Viewer.

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Read Autodesk Inventor document metadata and saved part geometry with a Rust parser and a Python API. Supported geometry can be converted to cq_acis.AcisModel and CadQuery objects. Runtime use does not require network access, Inventor, Windows, or user-provided schemas.

IPT → CFB / RSe → saved SAB / ASM → acis-core → AcisModel → CadQuery
IAM → saved references and placements → local part resolution → CadQuery Assembly

The parser supports a limited set of validated format profiles. It does not determine the current Model State, reevaluate feature history, or compute its own approximations of unsupported geometry. A B-spline fit that the file stores beside a procedural curve or surface is used as derived geometry and reported as a warning; see body conversion.

v0.4.0 adds body selection and IPT/IAM batch conversion. v0.10.0 makes the shape backend an install extra, adds an OCCT backend without CadQuery, and converts stored B-spline fits; see the v0.10.0 release notes.

v0.5.0 adds IDW sheet inventories and JSON reports, and per-sheet SVG export. See the release notes for supported drawing profiles, line styles and platform checks. Drawing support remains experimental and partial; physical scale and native rendering equivalence are unverified.

The release version is defined in Cargo.toml; see version management for the update command. The writer requires inventor-kit[cadquery]; see the writer guide.

Installation

Requires Python 3.11 or later, cq-acis>=0.4.2,<0.5, and shared model API 2. Where compatible published wheels are available, install with one shape backend:

python -m pip install 'inventor-kit[cadquery]'  # CadQuery shapes, STEP export, IAM, writers
python -m pip install 'inventor-kit[occt]'      # OCCT shapes only, without CadQuery

Since 0.10.0 a plain pip install inventor-kit installs the parser and the shared model only; earlier versions always installed CadQuery. The two extras ship different builds of the same OCP module, so install one of them.

Source builds use Rust 1.93, maturin, and acis-core / acis-py-bridge 0.4.2 from crates.io. See the development guide and release requirements.

Reading parts

import inventor_kit as ik
import cadquery as cq

doc = ik.read_file("part.ipt")
print(doc.summary["status"], doc.summary["diagnostics"])
if doc.model is not None:
    shape = doc.to_cadquery()  # Raises for unsupported surfaces, trims, etc.
    cq.exporters.export(shape, "part.step")

For metadata alone, use inspect_file, which does not import the Python geometry modules.

info = ik.inspect_file("part.ipt").metadata
for prop in info.find_properties(semantic_name="part_number"):
    print(prop.value, prop.source.stream, prop.state_binding)

python -m inventor_kit part.ipt
python -m inventor_kit part.ipt --step part.step
python -m inventor_kit drawing.idw --metadata-only
python -m inventor_kit part.ipt --list-candidates

For local visual inspection of parts and saved assemblies, install the optional viewer.

python -m pip install 'inventor-kit[viewer]'
python -m inventor_kit.viewer part.ipt

Model: NIST CTC 03 (saved geometry).

Reading assemblies

assembly = ik.read_assembly_file("assembly.iam", search_roots=["parts"])
converted = assembly.to_cadquery(allow_unverified_state=True, allow_partial=True)
print(converted.omissions, converted.reference_issues)
report = converted.export_step("assembly.step", allow_partial=True)

Using saved placements requires explicit opt-in. Missing parts and unsupported geometry remain recorded in the result. Because the current state is unverified, complete is False. Assembly STEP export refuses to overwrite existing files and writes provenance and omission details to an accompanying JSON report.

Limits and supported scope

limits = ik.Limits(max_file_bytes=32 * 1024 * 1024, max_candidates=16)
doc = ik.read_file("part.ipt", limits=limits)
print(ik.capabilities())

Limits can be lowered per document. They do not guarantee bounds on process memory, runtime, or OCCT computation. See the API guide for defaults, diagnostics, and saved candidate selection.

To bundle authored IPTs into an IAM, see the assembly writer: new_assembly and write-assembly. Select Inventor 2026 or 2027 with target_year (API) or --target-year (CLI); 2027 remains the default. Both bounded profiles passed native open/save/reopen and moved-bundle qualification.

Public samples are validated against pinned hashes and sources; the CAD files themselves are excluded from distribution packages.

License

The current inventor-kit distribution is source-available under PolyForm Noncommercial 1.0.0. For use outside PolyForm's permissions, UnRobotics Inc. offers separate commercial licenses. See licensing details for scope, earlier MIT permissions, and third-party license conditions.

Required Notice: inventor-kit is licensed by UnRobotics Inc. (https://www.un-robotics.com/).

Required Notice: This inventor-kit release is offered under PolyForm Noncommercial 1.0.0 or a separate commercial agreement; earlier MIT permissions and third-party terms remain in effect.