Shifty

Shifty validates RDF graphs against SHACL shapes and runs SHACL-AF rules to a fixed point. It compiles shapes into a path and shape algebra before evaluating data. The engine is available through a command-line tool, Python package, C++17 SDK, Rust crates, and WebAssembly module.

Documentation · Feature support · Changelog

Quick start

Install the Python package and its optional rdflib dependency when you want a W3C sh:ValidationReport graph:

pip install "pyshifty[rdflib]"

import shifty

shapes = """
@prefix sh: <http://www.w3.org/ns/shacl#> .
@prefix ex: <http://example.org/> .

ex:PersonShape a sh:NodeShape ;
    sh:targetClass ex:Person ;
    sh:property [ sh:path ex:name ; sh:minCount 1 ] .
"""
data = """
@prefix ex: <http://example.org/> .
ex:alice a ex:Person ; ex:name "Alice" .
ex:bob a ex:Person .
"""

result = shifty.validate_algebra(data, shapes)
assert not result.conforms
assert len(result.violations) == 1

conforms, report_graph, results_text = shifty.validate(data, shapes)
assert not conforms

validate_algebra() returns structured violations. validate() returns the W3C report as an rdflib.Graph. The Python reference lists their options and the other graph input forms.

For the CLI, clone this repository and install the binary with Rust:

cargo install --path crates/shifty-cli
shifty validate --shapes shapes.ttl --data data.ttl
shifty infer --shapes rules.ttl --data data.ttl

The CLI's default validation output groups failures by finding and lists the affected focus nodes. --report emits a W3C report in Turtle. See the CLI reference for flags and output formats.

Interfaces

Interface	Use
Python	Validation, inference, evidence, shape maps, and prepared schemas.
CLI	Validation and inference from files or URLs.
C++17	Static library with prepared validation and typed results.
Rust	Engine crates and reusable sessions.
WebAssembly	Local browser validation and inference; try the playground.

SHACL Core and much of SHACL-AF are supported. JavaScript constraints and functions are unsupported; some calls to SHACL functions from SPARQL have limited graph access. Check the feature matrix before relying on an advanced feature. Symbolic repair is experimental.

Development

The contribution guide has build and quality checks. Python development uses the locked uv environment in python/:

cd python
uv sync --dev --frozen --reinstall-package pyshifty
uv run ruff check .
uv run ruff format --check .
uv run ty check shifty
uv run pytest -q

Reinstall the editable package after changing Rust sources so tests use the newly compiled extension. For performance measurements and implementation comparisons, see benchmark/README.md and scripts/compare_implementations.py.

The archive-first-attempt branch preserves the older implementation published as Shifty 0.0.7. The current project was developed predominantly with coding assistants, including Claude Opus 4.8, Sonnet 4.6, and ChatGPT 5.5.

License

BSD-3-Clause.