OntoLogos

A modular Rust ontology reasoner in early development.

Display name: OntoLogos · Crates: ontologos-* · CLI binary: ontologos

v0.1 (today): in-memory ontology data model (ontologos-core) — build ontologies in Rust or load JSON v2 snapshots.

Planned: OWL file parsing (v0.2), profile detection (v0.2), RDFS/RL/EL reasoning (v0.3–v0.5), CLI and Python bindings.

If you need OWL classification today, use Protégé with HermiT or ELK. If you want to embed a Rust ontology graph or evaluate the architecture, start below.

What works in v0.1

Feature	Status
IRI intern pool, entity registry, axiom store	Available
`OntologyBuilder` programmatic construction	Available
JSON snapshot v2 (`to_json` / `from_json`)	Available
Axiom indexes (subclass, subproperty, equivalence, …)	Available
OWL file loading (`.owl`, `.ttl`, …)	v0.2
Profile detection	v0.2
RDFS / RL / EL reasoning	v0.3–v0.5
CLI subcommands beyond load	v0.2+
Python bindings	v0.9

Install (library)

Requires Rust 1.78+.

From crates.io:

[dependencies]
ontologos-core = "0.1.0"

From this repository:

git clone https://github.com/eddiethedean/ontologos.git
cd ontologos

API reference: docs.rs/ontologos-core

Quick start (5 minutes)

cargo run -p ontologos-core --example pizza_builder

Expected output (abbreviated):

Pizza direct superclasses: [EntityId(1)]
Superclass matches Thing: true
Entities: 4
Axioms: 2
Round-trip equal: true

Library usage

use ontologos_core::{Error, Ontology};

fn main() -> Result<(), Error> {
    let ontology = Ontology::builder()
        .class("http://example.org/Pizza")?
        .class("http://example.org/Food")?
        .subclass_of("http://example.org/Pizza", "http://example.org/Food")?
        .build()?;

    let json = ontology.to_json()?;
    let restored = Ontology::from_json(&json)?;
    assert_eq!(restored.axiom_count(), 1);
    Ok(())
}

Ontology::from_file returns Error::ParseNotAvailable until v0.2 parser support.

Workspace

Crate	Description	Status
`ontologos-core`	Core data model, ontology graph, and reasoner API	v0.1
`ontologos-parser`	OWL/RDF parsers (horned-owl integration)	Stub
`ontologos-profile`	OWL profile detection and diagnostics	Stub
`ontologos-rdfs`	RDFS reasoning engine	Stub
`ontologos-rl`	OWL RL forward-chaining rules	Stub
`ontologos-el`	OWL EL classification	Stub
`ontologos-query`	Query interface over classified ontologies	Stub
`ontologos-explain`	Proof graphs and explanation export	Stub
`ontologos-cli`	`ontologos` command-line tool	Stub
`ontologos-py`	Python bindings via PyO3	Stub

Only ontologos-core is published to crates.io in v0.1.0.

CLI (stub until v0.2)

The binary builds, but all subcommands fail at ontology load today:

cargo build -p ontologos-cli --release
./target/release/ontologos profile test.owl
# error: ontology file parsing is not available until v0.2

Planned commands: profile, classify, materialize, explain — see ROADMAP.md.

Python API (v0.9+)

Python bindings are stubbed; file loading requires v0.2.

Documentation

docs/README.md — documentation index and learning path
ROADMAP.md — versioned release plan (0.1 → 1.0 → 2.0)
CHANGELOG.md — release history
CONTRIBUTING.md — development workflow
FAQ.md — common questions
SPEC.md — technical specification (status-tagged)
docs/json-snapshot-v2.md — JSON snapshot format
docs/security.md — untrusted input guidance
docs/comparison.md — vs HermiT, ELK, and others
docs/internal/research/ — maintainer research notes

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.

ontologos-core 0.1.0