Open Ontologies

A Terraforming MCP for Knowledge Graphs Validate, classify, and govern AI-generated ontologies. Written in Rust. Ships as a single binary.

Quick Start · Studio · Benchmarks · Tools · Architecture · Docs

Open Ontologies is a Rust MCP server and desktop Studio for AI-native ontology engineering. It exposes 48 tools that let Claude build, validate, query, diff, lint, version, reason over, align, and persist RDF/OWL ontologies using an in-memory Oxigraph triple store — with Terraform-style lifecycle management, a marketplace of 29 standard ontologies, clinical crosswalks, semantic embeddings, and a full lineage audit trail.

The Studio wraps the engine in a visual desktop environment: 3D force-directed graph, AI chat panel, Protégé-style property inspector, and lineage viewer.

No JVM. No Protégé. No GUI required.

Screenshots

Full UI	3D Graph

Tissue ontology built in natural language. Gold edges show object property relationships (domain → range) connecting clusters; grey edges show subClassOf hierarchy. Spring-based force layout keeps related classes close.

Quick Start (MCP / CLI)

Install

Pre-built binaries:

# macOS (Apple Silicon)
curl -LO https://github.com/fabio-rovai/open-ontologies/releases/latest/download/open-ontologies-aarch64-apple-darwin
chmod +x open-ontologies-aarch64-apple-darwin && mv open-ontologies-aarch64-apple-darwin /usr/local/bin/open-ontologies

# macOS (Intel)
curl -LO https://github.com/fabio-rovai/open-ontologies/releases/latest/download/open-ontologies-x86_64-apple-darwin
chmod +x open-ontologies-x86_64-apple-darwin && mv open-ontologies-x86_64-apple-darwin /usr/local/bin/open-ontologies

# Linux (x86_64)
curl -LO https://github.com/fabio-rovai/open-ontologies/releases/latest/download/open-ontologies-x86_64-unknown-linux-gnu
chmod +x open-ontologies-x86_64-unknown-linux-gnu && mv open-ontologies-x86_64-unknown-linux-gnu /usr/local/bin/open-ontologies

Docker:

docker pull ghcr.io/fabio-rovai/open-ontologies:latest
docker run -i ghcr.io/fabio-rovai/open-ontologies serve

From source (Rust 1.85+):

git clone https://github.com/fabio-rovai/open-ontologies.git
cd open-ontologies && cargo build --release
./target/release/open-ontologies init

Connect to your MCP client

{
  "mcpServers": {
    "open-ontologies": {
      "command": "/path/to/open-ontologies/target/release/open-ontologies",
      "args": ["serve"]
    }
  }
}

{
  "mcpServers": {
    "open-ontologies": {
      "command": "/path/to/open-ontologies/target/release/open-ontologies",
      "args": ["serve"]
    }
  }
}

{
  "mcpServers": {
    "open-ontologies": {
      "command": "/path/to/open-ontologies/target/release/open-ontologies",
      "args": ["serve"]
    }
  }
}

{
  "mcpServers": {
    "open-ontologies": {
      "command": "do