# open-ontologies

AI-native ontology engine: a Rust MCP server with tools for building, validating, querying, and reasoning over RDF/OWL ontologies. In-memory Oxigraph triple store, native OWL2-DL tableaux reasoner, SHACL validation, SPARQL, versioning. Single binary, no JVM.

- Tier: Indexed (plain plugin)
- Category: Data
- Page: https://www.flowy.sh/listings/fabio-rovai-open-ontologies
- Source: https://github.com/fabio-rovai/open-ontologies
- Price: free and open source

## Summary
open-ontologies is a Claude Code plugin with 1 hand-picked skill for data work, indexed on Flowy. Install it with the command on its page. It includes ontology-engineering. Its skills do not fire on their own yet. Request auto-invocation to have Flowy route them as you prompt. Free and open source.

## Install (Claude Code)
```
npx -y skills add fabio-rovai/open-ontologies --agent claude-code
```

## Skills
- ontology-engineering

## FAQ

### What is open-ontologies?
AI-native ontology engine: a Rust MCP server with tools for building, validating, querying, and reasoning over RDF/OWL ontologies. In-memory Oxigraph triple store, native OWL2-DL tableaux reasoner, SHACL validation, SPARQL, versioning. Single binary, no JVM.

### How do I install open-ontologies?
Run these in Claude Code: npx -y skills add fabio-rovai/open-ontologies --agent claude-code. Then prompt normally.

### Does open-ontologies auto-invoke its skills?
Not yet. It is indexed on Flowy as a plain plugin. Request auto-invocation on its page and Flowy will route its skills for you as you prompt.

### Is open-ontologies free?
Yes. Flowy is free and open source, with nothing gated. You can read every skill in full before you install.