Getting Started

Five-minute success paths for common goals.

Crates.io only (no clone)

Use any OWL file on disk — no repository clone or benchmark download required.

cargo new ontologos-demo && cd ontologos-demo

Add to Cargo.toml:

[dependencies]
ontologos-core = "0.5.0"
ontologos-parser = "0.5.0"
ontologos-rdfs = "0.5.0"

src/main.rs:

use ontologos_parser::load_ontology;
use ontologos_rdfs::RdfsEngine;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut ontology = load_ontology(std::path::Path::new("ontology.owl"))?;
    let report = RdfsEngine::new().materialize(&mut ontology)?;
    println!(
        "inferred {} axioms ({} → {})",
        report.inferred_total(),
        report.initial_axiom_count,
        report.final_axiom_count
    );
    Ok(())
}

Place your OWL file at ontology.owl, then cargo run.

For OWL RL saturation, add ontologos-rl = "0.5.0" and see OWL RL saturation.

I want to try it from a clone

1. Clone and download benchmarks:

git clone https://github.com/eddiethedean/ontologos.git
cd ontologos
./benchmarks/scripts/download.sh

1. Run the builder example:

cargo run -p ontologos-core --example pizza_builder

1. Build the CLI and inspect an ontology:

cargo build -p ontologos-cli --release
./target/release/ontologos profile benchmarks/data/family.owl
./target/release/ontologos materialize benchmarks/data/family.owl

I want RDFS materialization

Follow RDFS materialization. Prefer CLI materialize over classify — both run the same engine in v0.4.

I want OWL RL saturation (v0.4 headline feature)

Follow OWL RL saturation or run:

cargo run -p ontologos-rl --example rl_saturation

OWL RL is not available in the CLI until v0.5 — use the library or Python profile="rl".

I'm integrating in Rust

Read Choosing an API then the guide for your workflow:

Goal	Guide
Build ontologies in code	First ontology
Load OWL files	Load an OWL file
RDFS materialization	RDFS materialization
OWL RL saturation	OWL RL saturation
JSON snapshots	JSON snapshot v2

I'm evaluating vs ELK / reasonable

See Comparison with existing tools and Conformance coverage.

I'm using Python

pip install ontologos

from ontologos import Reasoner

# Always set profile= — default "auto" fails in v0.4
Reasoner("ontology.owl", profile="rdfs").classify()

See Python guide.

Full learning path

See the documentation index.