# Ontology

Manage ontology schemas, concepts, alignments, and SHACL/OWL validation for Semantica...

- Repository: https://github.com/semantica-agi/semantica (14373 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add semantica-agi/semantica --skill ontology -g -a claude-code -y`
Codex: `npx skills add semantica-agi/semantica --skill ontology -g -a codex -y`
Cursor: `npx skills add semantica-agi/semantica --skill ontology -g -a cursor -y`
Gemini CLI: `npx skills add semantica-agi/semantica --skill ontology -g -a gemini-cli -y`

## Description

Manage ontology schemas, concepts, alignments, and SHACL/OWL validation for Semantica knowledge graphs. Uses OntologyEngine and OntologyValidator.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# /semantica:ontology

Manage ontology definitions and validation. Usage: `/semantica:ontology <task> [args]`

> Entry points: `OntologyEngine` (authoring, export, alignments) and
> `OntologyValidator` (consistency checking).

---

## `concepts <scheme_uri>`

List SKOS concepts in a vocabulary scheme.

```python
from semantica.ontology import OntologyEngine
from semantica.triplet_store import TripletStore

store = TripletStore(backend="oxigraph")   # needs semantica[tripletstore-oxigraph]
engine = OntologyEngine(store=store)       # list_concepts/list_vocabularies need a
                                            # configured store, raises ProcessingError without one
concepts = engine.list_concepts(scheme_uri)
vocabs = engine.list_vocabularies()
```

---

## `validate <ontology>`

Check an ontology for consistency and satisfiability.

```python
from semantica.ontology import OntologyValidator

validator = OntologyValidator(check_consistency=True, check_satisfiability=True)
result = validator.validate(ontology)   # dict or path to an ontology file
# result.valid, result.errors, result.warnings
```

For SHACL shape validation of instance data use `SHACLGenerator` / `SHACLValidationReport`:

```python
from semantica.ontology import SHACLGenerator
```

---

## `build <text|data>`

Generate an ontology from unstructured text or structured records.

```python
engine = OntologyEngine()
onto = engine.from_text(text)          # LLM-assisted (needs an llm-* extra + API key)
onto = engine.from_data(records)       # deterministic, from structured data
```

---

## `export <ontology> <path> [--format turtle]`

```python
engine.export_owl(onto, path, format="turtle")
engine.export_shacl(onto, path, format="turtle")
```

---

## `align <source_uri> <target_uri> <predicate>`

```python
engine.create_alignment(source_uri, target_uri, predicate)
engine.get_alignments(entity_uri)
engine.list_alignments()
```

---

## `evaluate <ontology>`

The rest: https://github.com/semantica-agi/semantica/blob/HEAD/plugins/skills/ontology/SKILL.md