parasolid-kit

A schema-aware parser for Parasolid X_T and X_B transmit files. A safe Rust core handles parsing and geometry mapping; Python exposes immutable typed models and a command-line interface. The project focuses on reading and preserving the transmitted structure for inspection and conversion pipelines.

Rust applications can use parasolid-core directly, without Python.

Features

• Inspect headers and map supported topology, analytic geometry and NURBS to a typed source B-Rep.
• Compare X_T/X_B documents after pointer remapping and reconstruct an unmodified parsed X_B document byte-for-byte.
• Report structured diagnostics and enforce configurable resource limits.
• Use optional OCCT conversion, validated STEP export, CadQuery shapes and a local viewer with face/edge source picking, body visibility and section views.

Installation

Python 3.10+ is required. The base package has no runtime dependencies:

python -m pip install parasolid-kit

For STEP export and the viewer, install the OCCT profile:

python -m pip install "parasolid-kit[occt]"

See installation for platform requirements, the separate CadQuery profile, downloaded wheels and source builds.

Quick start

For an input covered by a built-in profile:

parasolid-kit inspect model.x_b          # Header only; no schema catalog needed.
parasolid-kit check model.x_b            # Parse and check the source B-Rep.
parasolid-kit check model.x_t --json     # Structured report.
parasolid-kit compare model.x_t model.x_b

The same workflow is available in Python:

from parasolid_kit import read_brep

parsed = read_brep("model.x_b")
print(parsed.summary.to_dict())
print(parsed.complete)
print(parsed.brep.diagnostics)

complete describes source B-Rep mapping. Geometry conversion and a native CAD file's saved configuration have separate requirements. Use check when completeness must affect the CLI exit code. See the Python API and CLI reference for lower-level operations and diagnostics.

Local viewer

To try the viewer from a source checkout with Rust 1.88+ installed:

python -m pip install ".[occt]"
parasolid-kit viewer model.x_t --source-unit mm

Choose the input's actual unit; it is never inferred. view is an alias. The command opens a local URL; Ctrl-C stops serving and keeps the generated files. Node.js and a CDN are unnecessary at runtime.

Project-authored synthetic two-body fixture, rendered with Linux/SwiftShader. See preview controls and saving, display limits and viewer development.

Supported inputs

Built-in profiles cover exact Onshape V30/V13/current, extracted iCAD and SolidWorks partition keys and three transmit-file keys (NX and the Parasolid 24 and 26 acceptance tests). Each has verified_subset coverage and is completed by its schema family; application user fields are read. A key with no exact profile is read with the schema family of its effective schema and base (another Parasolid build of a reviewed schema) and reports family_inferred coverage; its node types must still be covered by the family's merged declarations. Consult the support matrix for exact keys, families and geometry limits; matching a key does not guarantee that all records are supported. Other schemas or uncovered types need an explicit schema catalog.

Native CAD containers and SolidWorks delta application are outside the complete parser contract. Assembly structure (instances and their transforms) is returned beside the B-Rep and is not applied to geometry or conversion. Parsing, OCCT conversion, STEP export and preview have separate coverage. See format support and limitations.

Documentation

License

The distribution is licensed under MIT AND Apache-2.0: the original implementation uses MIT, and adopted partial readers use Apache-2.0. See reader provenance and viewer notices.