Ontology authoring (OntoIndex v0.8)¶

Status: Documents behavior in OntoIndex v0.8.0. Pre-1.0 APIs may change. Canonical feature list: What ships today.

OntoCode provides Turtle write-back for simple and Manchester ontology edits without Protégé.

Supported operations¶

Operation	LSP / patch `op`
Create class, property, individual	`create_entity`
Delete entity	`delete_entity`
Add / set / remove label	`add_label`, `set_label`, `remove_label`
Add / set / remove comment	`add_comment`, `set_comment`, `remove_comment`
Add / remove parent class (named IRI)	`add_sub_class_of`, `remove_sub_class_of`
Add / remove complex `SubClassOf` (Manchester)	`add_complex_sub_class_of`, `remove_complex_sub_class_of`
Add / remove / set equivalent class (Manchester)	`add_equivalent_class`, `remove_equivalent_class`, `set_equivalent_class`
Add / remove disjoint class (named IRI)	`add_disjoint_class`, `remove_disjoint_class`
Set deprecated flag	`set_deprecated`

Full JSON reference: patch-reference.md.

Format policy¶

Write-back: Turtle (.ttl) only
Read/index: all supported RDF/OWL formats (unchanged)
Non-Turtle files are read-only in the explorer inspector (editable: false)

VS Code workflow (simple edits)¶

Open a .ttl ontology and select an entity in the OntoCode explorer.
Use the Entity Inspector edit section: add labels, comments, parents, or delete.
Use context menu Create Class/Property/Individual on explorer views.
Changes apply via ontoindex/applyAxiomPatch and trigger a workspace reindex.
VS Code undo works on saved file changes.

Manchester editor¶

For complex class expressions (restrictions, and/or, cardinality):

Select a class in a .ttl file.
In the Entity Inspector, click Edit in Manchester on a complex axiom row, or Add Manchester axiom.
Choose axiom type: SubClassOf, EquivalentClasses, or DisjointClasses (named class IRI for disjoint).
Enter a Manchester expression (e.g. ex:hasRecord some ex:MedicalRecord).
Use Insert pickers for classes, object properties, data properties, and XSD datatypes.
Validate shows parse diagnostics and an expression tree.
Preview shows the Turtle fragment; Apply writes the patch.

Manchester scope: named classes, and/or, some/only, min/max/exact cardinality, nesting, and DisjointClasses via IRI patch ops. Domain, range, and property chains appear in the axiom catalog (chains are view-only).

Workspace refactoring¶

For multi-file changes (rename IRI, namespace migration, move entity, extract module), use the refactor commands and Refactor Preview panel — see Refactoring guide.

Query workbench¶

Run OntoCode: Open Query Workbench from the Command Palette.

Toggle SQL or SPARQL mode
Run queries against the indexed workspace
Export results as CSV or JSON
Save named queries and reload from history
Use the virtual table dropdown for SQL table names

CLI¶

Example `patches.json`¶

[
  {
    "op": "create_entity",
    "entity_iri": "http://example.org/people#Student",
    "kind": "class"
  },
  {
    "op": "add_label",
    "entity_iri": "http://example.org/people#Student",
    "value": "Student"
  },
  {
    "op": "add_sub_class_of",
    "entity_iri": "http://example.org/people#Student",
    "parent_iri": "http://example.org/people#Person"
  }
]

ontoindex patch ./people.ttl patches.json --preview
ontoindex patch ./people.ttl patches.json
ontoindex validate .

More examples: patch-reference.md.

Horned-OWL dual stack¶

For Turtle files, catalog entities and axioms come from Horned-OWL via ontoindex-owl. Oxigraph remains authoritative for triple counts and SPARQL. CI runs owl_oxigraph_consistency tests on fixtures.

Unsaved buffers¶

When you apply a patch or Manchester edit in VS Code, the language server uses the open editor buffer as the source of truth (not only the file on disk). Unsaved edits in the buffer are preserved and patched in place. If reindex fails after a successful write, you may see APPLIED_NOT_INDEXED — run Index Workspace. See errors.md.

Limitations¶

Write-back is Turtle only
Complex axioms appear in the inspector and Manchester editor but not as edges in the class hierarchy tree (named-parent edges only; use reasoner for inferred hierarchy)
Manchester autocomplete uses catalog Insert pickers (no inline buffer autocomplete yet)
No SQL/SPARQL editor autocomplete in the workbench (v0.8+)