orionbelt-ontology-builder 0.9.0

A Streamlit application for building, editing, and managing OWL ontologies

OrionBelt Ontology Builder

Build, edit, and manage OWL ontologies visually with a Streamlit web application

Try it now: orionbelt.streamlit.app

Features

Core Functionality

• Create & Edit Ontologies - Build ontologies from scratch or modify existing ones
• Import/Export - Support for Turtle (.ttl), RDF/XML (.owl), N-Triples (.nt), N3 (.n3), and JSON-LD formats
• Validation - Check for missing labels, domains, ranges, and other issues
• Reasoning - Apply RDFS and OWL-RL reasoning to infer new triples
• Undo/Redo - Full undo/redo history for all ontology modifications
• Global Search - Search across all ontology elements
• Graph Visualization - Interactive vis-network graph with class filtering and layout options

Ontology Elements

Element	Operations
Classes	Create, edit, delete with hierarchy (subClassOf)
Object Properties	Domain/range, functional, transitive, symmetric, inverse
Data Properties	XSD datatypes (string, integer, date, boolean, etc.)
Individuals	Create instances, assign classes, property values
Restrictions	someValuesFrom, allValuesFrom, cardinality constraints
Annotations	RDFS labels/comments, SKOS, Dublin Core metadata
Relations	equivalentClass, disjointWith, sameAs, differentFrom

Quick Start

Prerequisites

• Python 3.10+

Installation

git clone https://github.com/ralfbecher/orionbelt-ontology-builder.git
cd orionbelt-ontology-builder
pip install -r requirements.txt

Run the Application

streamlit run app.py

Open your browser at http://localhost:8501

Workflow

1. Create New or Import - Start with a new ontology or import an existing .ttl file
2. Define Classes - Create your class hierarchy
3. Add Properties - Define object and data properties
4. Create Individuals - Add instances of your classes
5. Define Relations - Set up class/property/individual relationships
6. Add Restrictions - Apply constraints to classes
7. Validate - Check for issues using the validation button
8. Export - Download your ontology as .ttl or other formats

Pages Overview

Dashboard

• Ontology metadata (title, description, version, creator)
• Base URI configuration
• Statistics overview
• Quick validation button

Classes

• View class hierarchy
• Add/edit/delete classes
• Set parent classes (subClassOf)

Properties

• Object Properties - Relations between individuals
  • Characteristics: Functional, InverseFunctional, Transitive, Symmetric
  • Domain and range (classes)
• Data Properties - Attributes with literal values
  • XSD datatypes: string, integer, float, boolean, date, dateTime, etc.

Individuals

• Create named individuals
• Assign to classes
• Add property values (object or data)

Relations

• Class Relations: subClassOf, equivalentClass, disjointWith
• Property Relations: subPropertyOf, equivalentProperty, inverseOf
• Individual Relations: sameAs, differentFrom

Restrictions

• someValuesFrom / allValuesFrom
• hasValue
• Cardinality (min, max, exact)
• Qualified cardinality

Annotations

• RDFS: label, comment, seeAlso, isDefinedBy
• SKOS: prefLabel, altLabel, definition, example, note
• Dublin Core: title, description, creator, contributor, date

Import / Export

• Import: Upload files or paste content
• Export: Generate and download in multiple formats
• New Ontology: Create a fresh ontology with custom base URI

Validation

• Check for missing labels, domains, ranges
• Identify untyped individuals
• Apply OWL reasoning (RDFS, OWL-RL)

Visualization

• Interactive graph visualization with vis-network
• Class hierarchy tree view
• Statistics charts
• Class filter and configurable graph limits

Supported Formats

Format	Extension	Import	Export
Turtle	.ttl	✅	✅
RDF/XML	.owl, .rdf	✅	✅
N-Triples	.nt	✅	✅
N3	.n3	✅	✅
JSON-LD	.jsonld	❌	✅

Project Structure

orionbelt-ontology-builder/
├── app.py                 # Streamlit UI application
├── ontology_manager.py    # Core OWL operations using rdflib
├── requirements.txt       # Python dependencies
├── pyproject.toml         # Project metadata
├── lib/                   # Frontend vendor libraries
│   ├── vis-9.1.2/         # vis-network for graph visualization
│   ├── tom-select/        # Tom Select for enhanced dropdowns
│   └── bindings/          # JavaScript utility bindings
└── docs/
    └── assets/            # Logo assets

Dependencies

• streamlit - Web UI framework
• rdflib - RDF/OWL parsing and serialization
• owlrl - OWL-RL reasoning
• networkx - Graph operations
• pyvis - Network visualization

OWL Concepts Reference

Class Axioms

:Person a owl:Class .
:Student rdfs:subClassOf :Person .
:Male owl:disjointWith :Female .

Property Axioms

:hasParent a owl:ObjectProperty ;
    rdfs:domain :Person ;
    rdfs:range :Person ;
    owl:inverseOf :hasChild .

:hasAge a owl:DatatypeProperty ;
    rdfs:domain :Person ;
    rdfs:range xsd:integer .

Restrictions

:Parent rdfs:subClassOf [
    a owl:Restriction ;
    owl:onProperty :hasChild ;
    owl:someValuesFrom :Person
] .

Companion Project

OrionBelt Analytics

OrionBelt Analytics is an ontology-based MCP server that analyzes relational database schemas and generates RDF/OWL ontologies with embedded SQL mappings. It connects to PostgreSQL, Snowflake, and Dremio, providing AI assistants with deep structural and semantic understanding of your data. Together with the Ontology Builder, they form a comprehensive toolkit for ontology-driven data modeling.

License

Copyright 2025 RALFORION d.o.o.

Licensed under the Business Source License 1.1. The Licensed Work will convert to Apache License 2.0 on 2030-03-30.

By contributing to this project, you agree to the Contributor License Agreement.

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